2024 |
Upton R, Calatayud NE, Clulow S, Brett D, Burton AL, Colyvas K, et al., 'Refrigerated storage and cryopreservation of hormonally induced sperm in the threatened frog, Litoria aurea.', Anim Reprod Sci, 262 107416 (2024) [C1]
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Nova |
2023 |
Callen A, Pizzatto L, Stockwell MP, Clulow S, Clulow J, Mahony MJ, 'The effect of salt dosing for chytrid mitigation on tadpoles of a threatened frog, Litoria aurea', Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, 193 239-247 (2023) [C1]
The novel fungal pathogen Batrachochytrium dendrobatidis (chytrid) is one of the greatest threats to amphibians worldwide. Small increases in water salinity (up to ca. 4 ppt) have... [more]
The novel fungal pathogen Batrachochytrium dendrobatidis (chytrid) is one of the greatest threats to amphibians worldwide. Small increases in water salinity (up to ca. 4 ppt) have been shown to limit chytrid transmission between frogs, potentially providing a way to create environmental refugia to reduce its impact at a landscape scale. However, the effect of increasing water salinity on tadpoles, a life stage confined to water, is highly variable. Increased water salinity can lead to reduced size and altered growth patterns in some species, with flow-on effects to vital rates such as survival and reproduction. It is thus important to assess potential trade-offs caused by increasing salinity as a tool to mitigate chytrid in susceptible frogs. We conducted laboratory experiments to examine the effects of salinity on the survival and development of tadpoles of a threatened frog (Litoria aurea), previously demonstrated as a suitable candidate for trialling landscape manipulations to mitigate chytrid. We exposed tadpoles to salinity ranging from 1 to 6 ppt and measured survival, time to metamorphosis, body mass and locomotor performance of post-metamorphic frogs as a measure of fitness. Survival and time to metamorphosis did not differ between salinity treatments or controls reared in rainwater. Body mass was positively associated with increasing salinity in the first 14¿days. Juvenile frogs from three salinity treatments also showed the same or better locomotor performance compared to rainwater controls, confirming that environmental salinity may influence life history traits in the larval stage, potentially as a hormetic response. Our research suggests that salt concentrations in the range previously shown to improve survival of frogs in the presence of chytrid are unlikely to impact larval development of our candidate threatened species. Our study lends support to the idea of manipulating salinity to create environmental refugia from chytrid for at least some salt-tolerant species.
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Nova |
2023 |
Beranek CT, Clulow J, Mahony M, 'Life stage dependent predator-prey reversal between a frog (Litoria aurea) and a dragonfly (Anax papuensis).', Ecology, 104 e4108 (2023) [C1]
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Nova |
2023 |
Gould J, Clulow J, Rippon P, Upton R, Clulow S, 'All in one: single-season multi-clutching in an ephemeral pool-breeding frog that is otherwise virtually semelparous', Journal of Zoology, 320 226-235 (2023) [C1]
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Nova |
2023 |
Upton R, Clulow S, Colyvas K, Mahony M, Clulow J, 'Paradigm shift in frog sperm cryopreservation: reduced role for non-penetrating cryoprotectants.', Reproduction, 165 583-592 (2023) [C1]
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Nova |
2023 |
Howell LG, Mawson PR, Comizzoli P, Witt RR, Frankham R, Clulow S, et al., 'Modeling genetic benefits and financial costs of integrating biobanking into the conservation breeding of managed marsupials.', Conserv Biol, 37 e14010 (2023) [C1]
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Nova |
2023 |
Alley C, Beard P, Clulow J, Griffin A, Fawcett A, James G, Hayward MW, 'Assessing the effectiveness of long-term monitoring of the Broad-toothed Rat in the Barrington Tops National Park, Australia', Ecological Management and Restoration, 24 47-55 (2023) [C1]
Biodiversity monitoring is crucial for effective conservation efforts. Effective monitoring allows managers to determine the status and trends of biodiversity, as well as the succ... [more]
Biodiversity monitoring is crucial for effective conservation efforts. Effective monitoring allows managers to determine the status and trends of biodiversity, as well as the success of conservation actions. The population of the Broad-toothed Rats (Mastacomys fuscus) in the Barrington Tops National Park New South Wales, Australia has been monitored since 1999 via scat and live-trapping surveys. We reviewed the methods used and analysed the data produced with the aim of describing patterns of population change over time using a range of outcome variables and identifying different climate correlates. A secondary aim was to explore the use of population statistics that account for imperfect detection by comparing naïve occupancy, with an index of relative abundance based on trap effort, the latency to find scats during scat surveys and an occupancy model based on trapping surveys. Neither of these three methods accounts for detectability variation. Naïve occupancy decreased slightly over time, while the relative abundance based on trap effort revealed no evidence of change. Additionally, naïve occupancy decreased with increasing temperature while temperature had no clear impact on relative abundance. Finally, precipitation had no impact on either naïve occupancy or relative abundance. We found no evidence of a relationship between the latency to find scats and the index of relative abundance, suggesting that one or neither is related to actual abundance. Finally, a multi-season occupancy model found occupancy probability to be 0.78 ± 0.23 (standard error); detection probability as 0.51 ± 0.06; seasonal colonisation rate as 0.36 ± 0.13 and seasonal extinction rate at 0.44 ± 0.13. We conclude that despite significant investment in monitoring, this historical data set does not allow managers to ascertain whether population change has occurred and to identify potential drivers of change. Careful consideration of future methods, in particular, whether there is imperfect detection in scat surveys, will help to inform future monitoring.
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Nova |
2022 |
Mahony M, Gould J, Beranek CT, Callen A, Clulow J, Clulow S, et al., 'A trait-based analysis for predicting impact of wildfires on frogs', Australian Zoologist, 42 326-351 (2022) [C1]
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2022 |
Beranek CT, Sanders S, Clulow J, Mahony M, 'Factors influencing persistence of a threatened amphibian in restored wetlands despite severe population decline during climate change driven weather extremes', Biodiversity and Conservation, 31 1267-1287 (2022) [C1]
Biodiversity is in global decline during the Anthropocene. Declines have been caused by multiple factors, such as habitat removal, invasive species, and disease, which are often t... [more]
Biodiversity is in global decline during the Anthropocene. Declines have been caused by multiple factors, such as habitat removal, invasive species, and disease, which are often targets for conservation management. However, conservation interventions are under threat from climate change induced weather extremes. Weather extremes are becoming more frequent and devastating and an example of this was the 2019/2020 Australian drought and mega-fires. We provide a case study the impacts of these extreme weather events had on a population of the threatened frog Litoria aurea that occurs in a constructed habitat which was designed to reduce the impact of introduced fish and chytrid-induced disease. We aimed to determine what factors influenced persistence so that the design of wetlands can be further optimised to future-proof threatened amphibians. We achieved this with 4 years (2016¿2020) of intensive capture¿recapture surveys during austral spring and summer across nine wetlands (n = 94 repeat surveys). As hypothesized, drought caused a sharp reduction in population size, but persistence was achieved. The most parsimonious predictor of survival was an interaction between maximum air temperature and rainfall, indicating that weather extremes likely caused the decline. Survival was positively correlated with wetland vegetation coverage, positing this is an important feature to target to enhance resilience in wetland restoration programs. Additionally, the benefits obtained from measures to reduce chytrid prevalence were not compromised during drought, as there was a positive correlation between salinity and survival. We emphasize that many species may not be able to persist under worse extreme weather scenarios. Despite the potential for habitat augmentation to buffer effects of extreme weather, global action on climate change is needed to reduce extinction risk.
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Nova |
2022 |
Gould J, Clulow J, Clulow S, 'High clutch failure rate due to unpredictable rainfall for an ephemeral pool-breeding frog.', Oecologia, 198 699-710 (2022) [C1]
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Nova |
2022 |
Beranek CT, Maynard C, McHenry C, Clulow J, Mahony M, 'Identifying a limiting factor in the population dynamics of a threatened amphibian: The influence of extended female maturation on operational sex ratio', AUSTRAL ECOLOGY, 47 239-250 (2022) [C1]
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Nova |
2022 |
Gould J, Clulow J, Clulow S, 'Cheek-to-cheek: Communal nesting in an ephemeral pool-breeding frog', ETHOLOGY, 128 684-692 (2022) [C1]
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Nova |
2022 |
Gould J, Clulow J, Herb F, Clulow S, 'An ephemerality paradox: Evidence of virtual semelparity in ephemeral pool-breeding anurans', AUSTRAL ECOLOGY, 47 1591-1608 (2022) [C1]
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Nova |
2022 |
Garnham JI, Bower DS, Stockwell MP, Pickett EJ, Pollard CJ, Clulow J, Mahony MJ, 'Seasonal variation in the prevalence of a fungal pathogen and unexpected clearance from infection in a susceptible frog species', Diseases of Aquatic Organisms, 148 1-11 (2022) [C1]
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes the disease chytridiomycosis, which is a primary driver for amphibian population declines and extinctions w... [more]
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes the disease chytridiomycosis, which is a primary driver for amphibian population declines and extinctions worldwide. For highly susceptible species, such as the green and golden bell frog Litoria aurea, large numbers of Bd-related mortalities are thought to occur during the colder season (winter), when low temperatures favour the growth of the pathogen. However, extant L. aurea populations are persisting with Bd. We measured Bd prevalence and infection levels of wild L. aurea using capture-mark-recapture and radio-tracking methods. Using this information, we sought to determine host and environmental correlates of Bd prevalence and infection load. Mean ± SE infection load was higher in frogs sampled in autumn (431.5 ± 310.4 genomic equivalents; GE) and winter (1147.5 ± 735.8 GE), compared to spring (21.8 ± 19.3 GE) and summer (0.9 ± 0.8 GE). Furthermore, prevalence of Bd infection in L. aurea was highest in winter (43.6%; 95% CI 33.1-54.7%) and lowest in summer (11.2%; 95% CI 6.8-17.9%). Both prevalence and infection load decreased with increasing temperature. Seven frogs cleared their fungal infection during the coolest months when Bd prevalence was highest; however, these clearances were not permanent, as 5 frogs became infected again. Understanding the factors that allow amphibians to clear their Bd infections when temperatures are optimal for Bd growth presents the potential for manipulating such factors and provides an important step in future research.
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Nova |
2022 |
Clulow S, Clulow J, Marcec-Greaves R, Della Togna G, Calatayud NE, 'Common goals, different stages: the state of the ARTs for reptile and amphibian conservation', REPRODUCTION FERTILITY AND DEVELOPMENT, 34 I-IX (2022)
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2022 |
Howell LG, Johnston SD, O'Brien JK, Frankham R, Rodger JC, Ryan SA, et al., 'Modelling Genetic Benefits and Financial Costs of Integrating Biobanking into the Captive Management of Koalas', ANIMALS, 12 (2022) [C1]
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Nova |
2022 |
Beranek CT, Sanders S, Clulow J, Mahony M, 'Predator-free short-hydroperiod wetlands enhance metamorph output in a threatened amphibian: insights into frog breeding behaviour evolution and conservation management', WILDLIFE RESEARCH, 49 360-371 (2022) [C1]
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Nova |
2022 |
Knipler ML, Dowton M, Clulow J, Meyer N, Mikac KM, 'Genome-wide SNPs detect fine-scale genetic structure in threatened populations of squirrel glider Petaurus norfolcensis', Conservation Genetics, 23 541-558 (2022) [C1]
Australian arboreal mammals are experiencing significant population declines, particularly due to land clearing and resulting habitat fragmentation. The squirrel glider, Petaurus ... [more]
Australian arboreal mammals are experiencing significant population declines, particularly due to land clearing and resulting habitat fragmentation. The squirrel glider, Petaurus norfolcensis, is a threatened species in New South Wales, with a stronghold population in the Lake Macquarie Local Government Area (LGA) where fragmentation due to urbanization is an ongoing problem for the species conservation. Here we report on the use of squirrel glider mitochondrial (385¿bp cytochrome b gene, 70 individuals) and nuclear DNA (6,834 SNPs, 87 individuals) markers to assess their population genetic structure and connectivity across 14 locations sampled in the Lake Macquarie LGA. The mitochondrial DNA sequences detected evidence of a historical genetic bottleneck, while the genome-wide SNPs detected significant population structure in the Lake Macquarie squirrel glider populations at scales as fine as one kilometer. There was no evidence of inbreeding within patches, however there were clear effects of habitat fragmentation and biogeographical barriers on gene flow. A least cost path analysis identified thin linear corridors that have high priority for conservation. These areas should be protected to avoid further isolation of squirrel glider populations and the loss of genetic diversity through genetic drift.
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Nova |
2022 |
Howell LG, Clulow J, Jordan NR, Beranek CT, Ryan SA, Roff A, Witt RR, 'Drone thermal imaging technology provides a cost-effective tool for landscape-scale monitoring of a cryptic forest-dwelling species across all population densities', WILDLIFE RESEARCH, 49 66-78 (2022) [C1]
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Nova |
2022 |
Rodger JC, Clulow J, 'Resetting the paradigm of reproductive science and conservation', Animal Reproduction Science, 246 (2022) [C1]
In the application of reproductive science to conservation breeding, it has long been assumed that artificial insemination using frozen thawed sperm would be the default technolog... [more]
In the application of reproductive science to conservation breeding, it has long been assumed that artificial insemination using frozen thawed sperm would be the default technology. This has always been problematic considering the wide range of tolerance to freeze thawing among vertebrate sperm. Furthermore, those providing leadership for genome banking should be proactive to preserve maximum genetic diversity, however, for many species there is little or no sperm motility after thawing of cryopreserved sperm. In this review article, there is the contention that a much wider range of tissues should be banked, and the range of evolving advanced reproductive and developmental technologies should be considered for conservation breeding programs, to realize the maximum opportunities of genome banking to contribute to conservation of animal species.
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Nova |
2021 |
Klop-Toker KL, Valdez JW, Stockwell MP, Fardell L, Clulow S, Clulow J, Mahony MJ, 'Improving breed-and-release programmes in the face of a threatening pathogen, Batrachochytrium dendrobatidis', AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS, 31 2788-2803 (2021) [C1]
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Nova |
2021 |
Beranek CT, Xu G, Clulow J, Mahony M, 'Preliminary evidence for a two-for-one deal: Wetland restoration for a threatened frog may benefit a threatened bat', ECOLOGICAL MANAGEMENT & RESTORATION, 22 32-39 (2021) [C1]
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Nova |
2021 |
Campbell L, Clulow J, Howe B, Upton R, Doody S, Clulow S, 'Efficacy of short-term cold storage prior to cryopreservation of spermatozoa in a threatened lizard', Reproduction, Fertility and Development, 33 555-561 (2021) [C1]
Assisted reproductive technologies (ARTs) have a significant role to play in reptile conservation, yet are severely lacking. Previous attempts to cryopreserve spermatozoa in the t... [more]
Assisted reproductive technologies (ARTs) have a significant role to play in reptile conservation, yet are severely lacking. Previous attempts to cryopreserve spermatozoa in the threatened lizard Varanus panoptes achieved approximately 48% motile sperm post-thaw for samples frozen immediately after collection. However, the feasibility of extended cold storage before cryopreservation has not been tested. We held V. panoptes spermatozoa at either 258Cor 48C for 8 days, assessing sperm motility at days 1, 2, 4 and 8. Subsamples were cryopreserved on days 1 and 4 following the previously reported protocol for this species. Percentage motility decreased rapidly at 258C, but did not decrease significantly until 4 days after collection at 48C, with .30% motility maintained after 8 days. There was no significant difference in post-thaw motility or viability of samples cryopreserved after 1 or 4 days storage at 48C, yielding substantial results for both parameters (mean motility 23.8% and 28.1% and mean viability 50.1% and 57.5% after 1 and 4 days respectively). We demonstrate the capacity to extend sperm viability for up to 8 days in unfrozen samples and to produce acceptable post-thaw motility in samples frozen after 4 days of storage, contributing to the development of valuable ARTs for lizards and other reptiles.
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Nova |
2021 |
Howell LG, Frankham R, Rodger JC, Witt RR, Clulow S, Upton RMO, et al., 'Integrating biobanking could produce significant cost benefits and minimise inbreeding for Australian amphibian captive breeding programs', REPRODUCTION FERTILITY AND DEVELOPMENT, 33 573-587 (2021) [C1]
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Nova |
2021 |
Gould J, Valdez J, Clulow J, Clulow S, 'Left High and Dry: Froth Nesting Allows Eggs of the Anuran Amphibian to Complete Embryogenesis in the Absence of Free-Standing Water', Ichthyology and Herpetology, 109 537-544 (2021) [C1]
For amphibians that oviposit in temporary aquatic systems, there is a high risk of desiccation-induced offspring mortality when water evaporates prior to the completion of embryo ... [more]
For amphibians that oviposit in temporary aquatic systems, there is a high risk of desiccation-induced offspring mortality when water evaporates prior to the completion of embryo or tadpole development. Such a strong selective pressure has led to the evolution of a variety of traits in reproducing females and their offspring to improve the odds of reproductive success when free-standing water is temporarily available. Herein, we describe an adaptive function of froth nesting in the Sandpaper Frog, Lechriodus fletcheri, as a possible maternal strategy for protecting embryos from the immediate risk of desiccating in highly ephemeral pools that frequently dry prior to hatching. Field observations revealed that embryos located near the core of nests remained alive and continued to develop for several days after becoming stranded out of water due to declining water levels, with embryo viability maintained long enough for additional rainfall to recharge pools and support hatching of tadpoles into water in some cases. In laboratory trials, the proportion of embryos surviving in nests exposed to desiccating conditions was positively correlated with nest volume, while the rate of water loss relative to nest mass declined, both of which are likely a function of reduced surface area relative to volume in larger nests. We suggest that the encapsulation of embryos within an aerated mucus shields them from desiccation by trapping moisture around their external surfaces. As embryos of L. fletcheri complete development rapidly, the ability for the froth nest to protect against desiccation for several days may allow embryogenesis to be completed largely out of water despite the larval phase not being terrestrial. These results suggest froth nesting has played an important role in facilitating this species' use of ephemeral habitats that most other amphibians with aquatic reproductive modes are incapable of exploiting.
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Nova |
2021 |
Gould J, Clulow J, Rippon P, Doody JS, Clulow S, 'Complex trade-offs in oviposition site selection in a cannibalistic frog', Animal Behaviour, 175 75-86 (2021) [C1]
For oviparous animals such as amphibians, the presence or absence of conspecifics can influence site selection, with each life history stage potentially influencing the decision-m... [more]
For oviparous animals such as amphibians, the presence or absence of conspecifics can influence site selection, with each life history stage potentially influencing the decision-making process in a different manner. In the present study, we tested the effect of conspecific life history stage on oviposition site selection in the sandpaper frog, Lechriodus fletcheri. We quantified preferences for spawning in pools that were unused by conspecifics, as well as pools with conspecific spawn or tadpoles present, or both. The study included two ecological contexts: a system of naturally occurring breeding pools and a field experiment with 40 artificial pools that controlled for habitat variation. Mothers preferred to oviposit in pools that already contained conspecific spawn, despite the likelihood of intense resource competition upon offspring hatching. This could be due to the potential benefits obtained by providing offspring access to a significant nutrient supply upon hatching via cannibalism of conspecific tadpoles and might be an important adaptation for completing tadpole development in highly ephemeral and resource-limited pools prior to desiccation. In contrast, mothers avoided ovipositing in pools with conspecific tadpoles, a probable adaptation to avoid their own offspring from becoming victims of cannibalism themselves prior to hatching. Such nuances in the effect of conspecific presence on offspring survival highlight the often complex decision-making process that amphibians need to make when selecting oviposition sites, as well as the influence cannibalism can have on the evolution of reproductive behaviour.
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Nova |
2021 |
Campbell L, Clulow J, Doody JS, Clulow S, 'Optimal cooling rates for sperm cryopreservation in a threatened lizard conform to two-factor hypothesis of cryo-injury', CRYOBIOLOGY, 103 101-106 (2021) [C1]
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Nova |
2021 |
Meyer NF, King J-P, Mahony M, Clulow J, Beranek C, Reedman C, et al., 'Large area used by squirrel gliders in an urban area, uncovered using GPS telemetry', ECOLOGY AND EVOLUTION, 11 7147-7153 (2021) [C1]
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Nova |
2021 |
Campbell L, Clulow J, Howe B, Upton R, Doody S, Clulow S, 'Erratum: Efficacy of short-term cold storage prior to cryopreservation of spermatozoa in a threatened lizard (Reproduction, Fertility and Development (2021) DOI: 10.1071/RD20231)', Reproduction, Fertility and Development, 33 619 (2021)
Assisted reproductive technologies (ARTs) have a significant role to play in reptile conservation, yet are severely lacking. Previous attempts to cryopreserve spermatozoa in the t... [more]
Assisted reproductive technologies (ARTs) have a significant role to play in reptile conservation, yet are severely lacking. Previous attempts to cryopreserve spermatozoa in the threatened lizard Varanus panoptes achieved approximately 48% motile sperm post-thaw for samples frozen immediately after collection. However, the feasibility of extended cold storage before cryopreservation has not been tested. We held V. panoptes spermatozoa at either 25°C or 4°C for 8 days, assessing sperm motility at days 1, 2, 4 and 8. Subsamples were cryopreserved on days 1 and 4 following the previously reported protocol for this species. Percentage motility decreased rapidly at 25°C, but did not decrease significantly until 4 days after collection at 4°C, with >30% motility maintained after 8 days. There was no significant difference in post-thaw motility or viability of samples cryopreserved after 1 or 4 days storage at 4°C, yielding substantial results for both parameters (mean motility 23.8% and 28.1% and mean viability 50.1% and 57.5% after 1 and 4 days respectively). We demonstrate the capacity to extend sperm viability for up to 8 days in unfrozen samples and to produce acceptable post-thaw motility in samples frozen after 4 days of storage, contributing to the development of valuable ARTs for lizards and other reptiles.
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2021 |
Beranek CT, Clulow J, Mahony M, 'Genetic evidence for polyandry in the threatened green and golden bell frog', GENETICA, 149 327-333 (2021) [C1]
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Nova |
2021 |
Gould J, Clulow J, Clulow S, 'Using citizen science in the photo-identification of adult individuals of an amphibian based on two facial skin features.', PeerJ, 9 e11190 (2021) [C1]
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Nova |
2021 |
Upton R, Clulow S, Calatayud NE, Colyvas K, Seeto RGY, Wong LAM, et al., 'Generation of reproductively mature offspring from the endangered green and golden bell frog Litoria aurea using cryopreserved spermatozoa', Reproduction, Fertility and Development, 33 562-572 (2021) [C1]
Amphibians are becoming increasingly reliant on captive breeding programs for continued survival. Assisted reproductive technologies including gamete cryopreservation and IVF can ... [more]
Amphibians are becoming increasingly reliant on captive breeding programs for continued survival. Assisted reproductive technologies including gamete cryopreservation and IVF can help reduce costs of breeding programs, provide insurance against extinction and assist genetic rescue in wild populations. However, the use of these technologies to produce reproductively mature offspring has only been demonstrated in a few non-model species. We aimed to optimise sperm cryopreservation in the threatened frog Litoria aurea and generate mature offspring from frozen-thawed spermatozoa by IVF. We tested three concentrations (1.4, 2.1 and 2.8 M) of the cryoprotectants dimethylsulfoxide (DMSO) and glycerol with 0.3 M sucrose. Using DMSO was more likely to result in recovery of sperm motility, vitality and acrosome integrity than glycerol, regardless of concentration, with forward progressive motility being most sensitive to damage. The lowest concentrations of 1.4 and 2.1 M provided the best protection regardless of cryoprotectant type. Spermatozoa cryopreserved in 2.1 M DMSO outperformed spermatozoa cryopreserved in equivalent concentrations of glycerol in terms of their ability to fertilise ova, resulting in higher rates of embryos hatching and several individuals reaching sexual maturity. We have demonstrated that sperm cryopreservation and subsequent offspring generation via IVF is a feasible conservation tool for L. aurea and other threatened amphibians.
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Nova |
2021 |
Beranek CT, Maynard C, McHenry C, Clulow J, Mahony M, 'Rapid population increase of the threatened Australian amphibian Litoria aurea in response to wetlands constructed as a refuge from chytrid-induced disease and introduced fish', JOURNAL OF ENVIRONMENTAL MANAGEMENT, 291 (2021) [C1]
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Nova |
2021 |
Bugir CK, Peres CA, White KS, Montgomery RA, Griffin AS, Rippon P, et al., 'Prey preferences of modern human hunter-gatherers', FOOD WEBS, 26 (2021) [C1]
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Nova |
2021 |
Howell LG, Frankham R, Rodger JC, Witt RR, Clulow S, Upton RMO, Clulow J, 'Integrating biobanking minimises inbreeding and produces significant cost benefits for a threatened frog captive breeding programme', Conservation Letters, 14 (2021) [C1]
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Nova |
2020 |
Beranek CT, Clulow J, Mahony M, 'Wetland Restoration for the Threatened Green and Golden Bell Frog (Litoria aurea): Development of a Breeding Habitat Designed to Passively Manage Chytrid-Induced Amphibian Disease and Exotic Fish', Natural Areas Journal, 40 362-374 (2020) [C1]
Amphibians are under threat from many drivers resulting in declining populations. Restoration and creation of habitat is a method used to reverse amphibian declines. The green and... [more]
Amphibians are under threat from many drivers resulting in declining populations. Restoration and creation of habitat is a method used to reverse amphibian declines. The green and golden bell frog (Litoria aurea) is distributed in southeastern Australia, and is threatened by the fungal pathogen Batrachochytrium dendobatidis (chytrid), an introduced fish (the plague minnow, Gambusia holbrooki), and habitat loss. There have been numerous wetland restoration attempts to combat population declines in this species, which have been largely unsuccessful in producing persisting populations. Here we present a robust model for the creation of breeding habitat for the L. aurea population on Kooragang Island, New South Wales, which is based off thorough review of the literature and past pilot studies and experiments. We describe in detail the habitat, land use history, and wetland habitat design formulation and construction so that the context of the habitat creation is understood and so construction can be repeatable and the design can be further refined. The habitat features passive controls for chytrid and G. holbrooki, and contains the most optimum breeding habitat for L. aurea based upon current knowledge. This is the first attempt in our knowledge to create wetlands in an open system that have the potential to passively manage chytrid.
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Nova |
2020 |
Beranek CT, Clulow J, Mahony M, 'A simple design feature to increase hydro-period in constructed ephemeral wetlands to avoid tadpole desiccation-induced mortality', ECOLOGICAL MANAGEMENT & RESTORATION, 21 250-253 (2020) [C1]
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Nova |
2020 |
Campbell L, Cafe SL, Upton R, Doody JS, Nixon B, Clulow J, Clulow S, 'A model protocol for the cryopreservation and recovery of motile lizard sperm using the phosphodiesterase inhibitor caffeine', CONSERVATION PHYSIOLOGY, 8 (2020) [C1]
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Nova |
2020 |
Della Togna G, Howell LG, Clulow J, Langhorne CJ, Marcec-Greaves R, Calatayud NE, 'Evaluating amphibian biobanking and reproduction for captive breeding programs according to the Amphibian Conservation Action Plan objectives', THERIOGENOLOGY, 150 412-431 (2020) [C1]
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Nova |
2020 |
Gould J, Clulow J, Clulow S, 'Food, not friend: Tadpoles of the sandpaper frog (Lechriodus fletcheri) cannibalise conspecific eggs as a food resource in ephemeral pools', Ethology, 126 486-491 (2020) [C1]
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Nova |
2020 |
Callen A, Hayward MW, Klop-Toker K, Allen BL, Ballard G, Beranek CT, et al., 'Response to comments on "Compassionate Conservation deserves a morally serious rather than dismissive response - reply to Callen et al., 2020"', BIOLOGICAL CONSERVATION, 244 (2020)
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2020 |
Callen A, Hayward MW, Klop-Toker K, Allen BL, Ballard G, Broekhuis F, et al., 'Envisioning the future with compassionate conservation : An ominous projection for native wildlife and biodiversity', Biological Conservation, 241 (2020) [C1]
The ¿Compassionate Conservation¿ movement is gaining momentum through its promotion of ¿ethical¿ conservation practices based on self-proclaimed principles of ¿first-do-no-harm¿ a... [more]
The ¿Compassionate Conservation¿ movement is gaining momentum through its promotion of ¿ethical¿ conservation practices based on self-proclaimed principles of ¿first-do-no-harm¿ and ¿individuals matter¿. We argue that the tenets of ¿Compassionate Conservation¿ are ideological - that is, they are not scientifically proven to improve conservation outcomes, yet are critical of the current methods that do. In this paper we envision a future with ¿Compassionate Conservation¿ and predict how this might affect global biodiversity conservation. Taken literally, ¿Compassionate Conservation¿ will deny current conservation practices such as captive breeding, introduced species control, biocontrol, conservation fencing, translocation, contraception, disease control and genetic introgression. Five mainstream conservation practices are used to illustrate the far-reaching and dire consequences for global biodiversity if governed by ¿Compassionate Conservation¿. We acknowledge the important role of animal welfare science in conservation practices but argue that ¿Compassionate Conservation¿ aligns more closely with animal liberation principles protecting individuals over populations. Ultimately we fear that a world of ¿Compassionate Conservation¿ could stymie the global conservation efforts required to meet international biodiversity targets derived from evidenced based practice, such as the Aichi targets developed by the Convention on Biological Diversity and adopted by the International Union for the Conservation of Nature and the United Nations.
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Nova |
2020 |
Witt RR, Beranek CT, Howell LG, Ryan SA, Clulow J, Jordan NR, et al., 'Real-time drone derived thermal imagery outperforms traditional survey methods for an arboreal forest mammal', PLOS ONE, 15 (2020) [C1]
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Nova |
2019 |
Campbell L, Bower DS, Clulow S, Stockwell M, Clulow J, Mahony M, 'Interaction between temperature and sublethal infection with the amphibian chytrid fungus impacts a susceptible frog species', SCIENTIFIC REPORTS, 9 (2019) [C1]
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Nova |
2019 |
Hayward MW, Jachowski D, Bugir CK, Clulow J, Krishnamurthy R, Griffin AS, et al., 'The search for novelty continues for rewilding', BIOLOGICAL CONSERVATION, 236 584-585 (2019)
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2019 |
Gould J, Valdez JW, Clulow J, Clulow S, 'Diving beetle offspring oviposited in amphibian spawn prey on the tadpoles upon hatching', ENTOMOLOGICAL SCIENCE, 22 393-397 (2019) [C1]
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Nova |
2019 |
Valdez JW, Klop-Toker K, Stockwell MP, Fardell L, Clulow S, Clulow J, Mahony MJ, 'Informing compensatory habitat creation with experimental trials: a 3-year study of a threatened amphibian', ORYX, 53 310-320 (2019) [C1]
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Nova |
2019 |
Gould J, Valdez J, Clulow S, Clulow J, 'Diving beetle offspring oviposited in amphibian spawn prey on the tadpoles upon hatching (2019)
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2019 |
Hayward MW, Scanlon RJ, Callen A, Howell LG, Klop-Toker KL, Di Blanco Y, et al., 'Reintroducing rewilding to restoration Rejecting the search for novelty', Biological Conservation, 233 255-259 (2019) [C1]
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Nova |
2019 |
Hayward MW, Callen A, Allen BL, Ballard G, Broekhuis F, Bugir C, et al., 'Deconstructing compassionate conservation', Conservation Biology, 33 760-768 (2019) [C1]
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Rece... [more]
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.
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Nova |
2019 |
Browne RK, Silla AJ, Upton R, Della-Togna G, Marcec-Greaves R, Shishova NV, et al., 'Sperm collection and storage for the sustainable management of amphibian biodiversity', Theriogenology, 133 187-200 (2019) [C1]
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Nova |
2018 |
Clulow S, Gould J, James H, Stockwell M, Clulow J, Mahony M, 'Elevated salinity blocks pathogen transmission and improves host survival from the global amphibian chytrid pandemic: Implications for translocations', JOURNAL OF APPLIED ECOLOGY, 55 830-840 (2018) [C1]
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Nova |
2018 |
Upton R, Clulow S, Mahony MJ, Clulow J, 'Generation of a sexually mature individual of the Eastern dwarf tree frog, Litoria fallax, from cryopreserved testicular macerates: proof of capacity of cryopreserved sperm derived offspring to complete development', CONSERVATION PHYSIOLOGY, 6 (2018) [C1]
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Nova |
2018 |
Klop-Toker K, Valdez J, Stockwell M, Clulow S, Clulow J, Mahony M, 'Community level impacts of invasive mosquitofish may exacerbate the impact to a threatened amphibian', Austral Ecology, 43 213-224 (2018) [C1]
Invasive fish threaten many native freshwater fauna. However, it can be difficult to determine how invasive fish impact animals with complex life cycles as interaction may be driv... [more]
Invasive fish threaten many native freshwater fauna. However, it can be difficult to determine how invasive fish impact animals with complex life cycles as interaction may be driven by either predation of aquatic larvae or avoidance of fish-occupied waterbodies by the terrestrial adult stage. Mosquitofish (Gambusia spp.) are highly successful and aggressive invaders that negatively impact numerous aquatic fauna. One species potentially threatened by Gambusia holbrooki is the green and golden bell frog (Litoria aurea). However, G.¿holbrooki's role in this frog's decline was unclear due to declines driven by the chytrid fungal disease and the continued co-existence of these fish and frogs in multiple locations. To clarify the extent to which Gambusia is impacting L.¿aurea, we conducted 3¿years of field surveys across a deltaic wetland system in south-east Australia. We measured the presence and abundance of aquatic taxa including G.¿holbrooki, and L.¿aurea frogs and tadpoles, along with habitat parameters at the landscape and microhabitat scale. Generalized linear models were used to explore patterns in the abundance and distributions of L.¿aurea and G.¿holbrooki. We¿found strong negative associations between G.¿holbrooki and tadpoles of most species, including L.¿aurea, but no apparent avoidance of G.¿holbrooki by adult frogs. Native invertebrate predators (Odonata and Coleoptera) were also absent from G.¿holbrooki-occupied ponds. Due to the apparent naivety of adult frogs toward G.¿holbrooki, the separation of G.¿holbrooki and tadpoles, plus the abundance of alternative predators in G.¿holbrooki-free ponds, we conclude that the impact of G.¿holbrooki on L.¿aurea recruitment is likely substantial and warrants management action.
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Nova |
2018 |
Fardell L, Valdez J, Klop-Toker K, Stockwell M, Clulow S, Clulow J, Mahony M, 'Effects of vegetation density on habitat suitability for the endangered green and golden bell frog, Litoria aurea', Herpetological Conservation and Biology, 13 47-57 (2018) [C1]
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Nova |
2018 |
Clulow J, Pomering M, Herbert D, Upton R, Calatayud N, Clulow S, et al., 'Differential success in obtaining gametes between male and female Australian temperate frogs by hormonal induction: A review', GENERAL AND COMPARATIVE ENDOCRINOLOGY, 265 141-148 (2018) [C1]
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Nova |
2017 |
Pollard CJ, Stockwell MP, Bower DS, Clulow J, Mahony MJ, 'Combining
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Nova |
2017 |
Klop-Toker KL, Valdez JW, Stockwell MP, Edgar ME, Fardell L, Clulow S, et al., 'Assessing host response to disease treatment: how chytrid-susceptible frogs react to increased water salinity', WILDLIFE RESEARCH, 44 648-659 (2017) [C1]
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Nova |
2017 |
Pollard CJ, Stockwell MP, Bower DS, Garnham JI, Pickett EJ, Darcovich K, et al., 'Removal of an exotic fish influences amphibian breeding site selection', JOURNAL OF WILDLIFE MANAGEMENT, 81 720-727 (2017) [C1]
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Nova |
2017 |
Valdez JW, Klop-Toker K, Stockwell MP, Fardell L, Clulow S, Clulow J, Mahony MJ, 'Differences in microhabitat selection patterns between a remnant and constructed landscape following management intervention', WILDLIFE RESEARCH, 44 248-258 (2017) [C1]
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Nova |
2016 |
Klop-Toker K, Valdez J, Stockwell M, Fardell L, Clulow S, Clulow J, Mahony M, 'We Made Your Bed, Why Won't You Lie in It? Food Availability and Disease May Affect Reproductive Output of Reintroduced Frogs', PLOS ONE, 11 (2016) [C1]
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Nova |
2016 |
Abu Bakar A, Bower DS, Stockwell MP, Clulow S, Clulow J, Mahony MJ, 'Susceptibility to disease varies with ontogeny and immunocompetence in a threatened amphibian', Oecologia, 181 997-1009 (2016) [C1]
Ontogenetic changes in disease susceptibility have been demonstrated in many vertebrate taxa, as immature immune systems and limited prior exposure to pathogens can place less dev... [more]
Ontogenetic changes in disease susceptibility have been demonstrated in many vertebrate taxa, as immature immune systems and limited prior exposure to pathogens can place less developed juveniles at a greater disease risk. By causing the disease chytridiomycosis, Batrachochytrium dendrobatidis (Bd) infection has led to the decline of many amphibian species. Despite increasing knowledge on how Bd varies in its effects among species, little is known on the interaction between susceptibility and development within host species. We compared the ontogenetic susceptibility of post-metamorphic green and golden bell frogs Litoria aurea to chytridiomycosis by simultaneously measuring three host-pathogen responses as indicators of the development of the fungus¿infection load, survival rate, and host immunocompetence¿following Bd exposure in three life stages (recently metamorphosed juveniles, subadults, adults) over 95¿days. Frogs exposed to Bd as recently metamorphosed juveniles acquired higher infection loads and experienced lower immune function and lower survivorship than subadults and adults, indicating an ontogenetic decline in chytridiomycosis susceptibility. By corresponding with an intrinsic developmental maturation in immunocompetence seen in uninfected frogs, we suggest these developmental changes in host susceptibility in L. aurea may be immune mediated. Consequently, the physiological relationship between ontogeny and immunity may affect host population structure and demography through variation in life stage survival, and understanding this can shape management targets for effective amphibian conservation.
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Nova |
2016 |
Pizzatto L, Stockwell M, Clulow S, Clulow J, Mahony M, 'Finding a place to live: conspecific attraction affects habitat selection in juvenile green and golden bell frogs', Acta Ethologica, 19 1-8 (2016) [C1]
Conspecific attraction plays an important role in habitat selection of several taxa and can affect and determine distribution patterns of populations. The behaviour is largely stu... [more]
Conspecific attraction plays an important role in habitat selection of several taxa and can affect and determine distribution patterns of populations. The behaviour is largely studied and widespread among birds, but in amphibians, its occurrence seems limited to breeding habitats of adults and gregarious tadpoles. The Australian green and golden bell frogs (Litoria aurea) have suffered considerable shrinking of their original distribution in south-eastern Australia since the 1970s. Currently, with only about 40 populations remaining, the species is considered nationally threatened. In natural conditions, these frogs are aggregated in the landscape and do not seem to occupy all suitable ponds within the occurrence area. To date, studies focusing on the frogs¿ habitat have failed in finding a general habitat feature that explains current or past occupancy. This led us to the hypothesis that social cues may play a key role in habitat selection in this species. Using two choice experiments, we tested the preference of juvenile green and golden bell frogs for habitats containing cues of conspecifics of similar size versus habitats without conspecific cues. Tested frogs did not show a preference for habitats containing only scent from conspecifics but did prefer habitats where conspecifics were present. Our results show that conspecific attraction is a determining factor in juvenile green and golden bell frog habitat selection. To our knowledge, this is the first time the behaviour is shown to occur in juvenile frogs in the habitat selection context. From a conservation management point of view, the behaviour may help to explain the failure of reintroductions to areas where the frogs have been extinct, and the non-occupation of suitable created habitats in areas where they still inhabit and develop appropriated management strategies.
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Nova |
2016 |
Valdez J, Klop-Toker K, Stockwell MP, Clulow S, Clulow J, Mahony MJ, 'Microhabitat selection varies by sex and age class in the endangered green and golden bell frog Litoria aurea', Australian Zoologist, 38 223-234 (2016) [C1]
Although amphibians are one of the most threatened animal groups, little published evidence exists on effective management programs. In order for conservation initiatives to be su... [more]
Although amphibians are one of the most threatened animal groups, little published evidence exists on effective management programs. In order for conservation initiatives to be successful, an understanding of habitat use patterns is required to identify important environmental features. However, habitat use may differ between the different sexes and age classes due to different behavioural and resource requirements. For this study, we compared microhabitat use during the active breeding season among the sexes and age classes in the endangered green and golden bell frog Litoria aurea, a species which has had several failed management programs. We found aquatic vegetation was selected for by every L. aurea class, and should be the focus of future management plans for this species. Females were the only class to select for terrestrial vegetation more than availability. Increasing the amount of terrestrial vegetation around ponds may help encourage female occupancy, and possibly improve management outcomes, as they are typically a limiting resource. Although large rock piles have been used in past L. aurea habitat management, they were selected for by adults and juveniles, but not metamorphs. Therefore, large rocks may not be necessary for captive breeding portions of management initiatives, which typically only involve tadpoles and metamorphs prior to release. The results indicate that the most appropriate management plans should contain a habitat mosaic of various microhabitats, such as a large proportion of aquatic and terrestrial vegetation with patches of bare ground and a small proportion of rocks for basking and shelter. Recognizing differences in microhabitat use patterns between individuals in a population and implementing them into management strategies should be a pivotal step in any conservation plan.
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Nova |
2016 |
Clulow J, Clulow S, 'Cryopreservation and other assisted reproductive technologies for the conservation of threatened amphibians and reptiles: bringing the ARTs up to speed.', Reproduction, fertility, and development, (2016) [C1]
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Nova |
2016 |
Stockwell MP, Garnham JI, Bower DS, Clulow J, Mahony MJ, 'Low disease-causing threshold in a frog species susceptible to chytridiomycosis', FEMS MICROBIOLOGY LETTERS, 363 (2016) [C1]
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Nova |
2016 |
Pickett EJ, Stockwell MP, Clulow J, Mahony MJ, 'Modelling the population viability of a threatened amphibian with a fast life-history', Aquatic Conservation: Marine and Freshwater Ecosystems, 26 9-19 (2016) [C1]
A bias in conservation research has meant that population viability analysis has focused primarily on mammals and birds with slow life histories. The global amphibian decline has ... [more]
A bias in conservation research has meant that population viability analysis has focused primarily on mammals and birds with slow life histories. The global amphibian decline has demonstrated the capacity for fast life-history species to experience decline. However, little is known about the viability of remnant populations of these species as patterns of decline cannot be inferred from other species with different life-history strategies. Population viability analysis was performed on the threatened frog, Litoria aurea, which exhibits high temporal variability in population size due to its fast life-history traits. Projections of population size from the viability model were highly variable, and removing parametric uncertainty only slightly improved overall model certainty, thus demonstrating the limits of population viability analysis for predicting abundance in fast life-history species. Sensitivity analysis identified recruitment of adults, female survival, male survival and rate of maturity as having the most impact on population viability. This population viability model provides a starting point to incorporate future research findings and better elucidate the causes of local extinction in this species. This study also reinforces the importance of egg-juvenile survival for amphibian populations, but also exemplifies the variability of amphibian viability analyses for identifying important parameters. As a case study for amphibian conservation, this analysis shows the utility of population viability analyses for fast life-history species, even with incomplete knowledge of all life-history stages.
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Nova |
2016 |
Pizzatto L, Clulow J, Mahony M, 'Eye malformation and body coloration in Litoria aurea tadpoles', SALAMANDRA, 52 207-210 (2016) [C1]
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Nova |
2016 |
Stockwell MP, Bower DS, Clulow J, Mahony MJ, 'The role of non-declining amphibian species as alternative hosts for Batrachochytrium dendrobatidis in an amphibian community', WILDLIFE RESEARCH, 43 341-347 (2016) [C1]
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Nova |
2016 |
Remon J, Bower DS, Gaston TF, Clulow J, Mahony MJ, 'Stable isotope analyses reveal predation on amphibians by a globally invasive fish (Gambusia holbrooki)', Aquatic Conservation: Marine and Freshwater Ecosystems, 26 724-735 (2016) [C1]
Biodiversity loss caused by invasive species is particularly problematic in freshwater ecosystems, which are among the world's most threatened habitats. Invasive fish such as... [more]
Biodiversity loss caused by invasive species is particularly problematic in freshwater ecosystems, which are among the world's most threatened habitats. Invasive fish such as the eastern mosquitofish, Gambusia holbrooki, have been implicated in the decline of amphibians, which suffer high extinction rates globally. Although G. holbrooki is one of the most studied freshwater fish, its diet shows wide geographic variation and its impact on amphibian populations remains unclear. Stable isotopes 13C and 15N were used in 10 urban ponds in Sydney, Australia to compare the diet of G. holbrooki in January, April and May 2013 using a stable isotope mixing model. Gambusia holbrooki was carnivorous and fed on invertebrates (24¿39%), tadpoles (25¿32%) and conspecifics (20¿45%). In contrast to previous studies, primary producers were a negligible part of Gambusia holbrooki diet (<10%). Its diet in late autumn comprised a high proportion of conspecifics (up to 45%) owing to the depletion of other food sources before winter (metamorphosis of larvae). This study provides evidence of high rates of predation on native tadpoles and invertebrates by a highly invasive fish. This knowledge should be incorporated into amphibian releases through head-starting tadpoles or using soft releases where tadpoles are placed in predator-free enclosures until larvae are large enough to avoid predation. Considering the dire conservation status of amphibians globally and the growing interest for invertebrates, it is suggested that stable isotopes are valuable to identify threats from predation in order to target conservation practice toward suitable priorities. Copyright © 2016 John Wiley & Sons, Ltd.
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Nova |
2016 |
Bower DS, Scheltinga DM, Clulow S, Clulow J, Franklin CE, Georges A, 'Salinity tolerances of two Australian freshwater turtles, Chelodina expansa and Emydura macquarii (Testudinata: Chelidae).', Conserv Physiol, 4 cow042 (2016) [C1]
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Nova |
2016 |
Pizzatto L, Stockwell M, Clulow S, Clulow J, Mahony M, 'How to form a group: Effects of heterospecifics, kinship and familiarity in the grouping preference of green and golden bell frog tadpoles', Herpetological Journal, 26 157-164 (2016) [C1]
Social aggregations are widespread among animal groups. They are relatively common in amphibian larvae, likely conferring protection against predators, advantages for microhabitat... [more]
Social aggregations are widespread among animal groups. They are relatively common in amphibian larvae, likely conferring protection against predators, advantages for microhabitat selection, foraging efficiency, and thermoregulatory efficiency. Group formation involves selection of individuals to group with by the other members, and several tadpoles are reported to recognise and prefer to aggregate with siblings or familiar individuals. In Australia, tadpoles of the endangered green and golden bell frog, Litoria aurea, are attracted to conspecifics and form schools. We conducted two choice experiments for captive breed tadpoles of this species to test their grouping preferences. Tadpoles preferred to aggregate with conspecifics to heterospecifics of a sympatric species; however, when conspecifics were absent they preferred to aggregate with the heterospecifcs than to remain alone. Tadpoles also preferred unfamiliar kin to unfamiliar non-kin conspecifics, but had no preferences between unfamiliar and familiar siblings. Once widespread in southeast Australia, the green and golden bell frog has suffered considerable declines and local extinctions in recent decades. Susceptibility to chytridiomycosis is likely the major threat for most remaining fragmented populations and the major challenge for reintroduction programs. The strong gregarious behaviour of this species may affect disease dynamics, especially chytridiomicosis that continues to threaten remaining wild populations.
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Nova |
2015 |
Sanders MR, Clulow S, Bower DS, Clulow J, Mahony MJ, 'Predator Presence and Vegetation Density Affect Capture Rates and Detectability of Litoria aurea Tadpoles: Wide-Ranging Implications for a Common Survey Technique.', PloS one, 10 e0143733 (2015) [C1]
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Nova |
2015 |
Stockwell MP, Storrie LJ, Pollard CJ, Clulow J, Mahony MJ, 'Effects of pond salinization on survival rate of amphibian hosts infected with the chytrid fungus', Conservation Biology, 29 391-399 (2015) [C1]
The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. Recent ... [more]
The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. Recent studies show that sodium chloride (NaCl) has fungicidal properties that reduce the mortality rates of infected hosts in captivity. We investigated whether similar results can be obtained by adding salt to water bodies in the field. We increased the salinity of 8 water bodies to 2 or 4 ppt and left an additional 4 water bodies with close to 0 ppt and monitored salinity for 18 months. Captively bred tadpoles of green and golden bell frog (Litoria aurea) were released into each water body and their development, levels of B. dendrobatidis infection, and survival were monitored at 1, 4, and 12 months. The effect of salt on the abundance of nontarget organisms was also investigated in before and after style analyses. Salinities remained constant over time with little intervention. Hosts in water bodies with 4 ppt salt had a significantly lower prevalence of chytrid infection and higher survival, following metamorphosis, than hosts in 0 ppt salt. Tadpoles in the 4 ppt group were smaller in length after 1 month in the release site than those in the 0 and 2 ppt groups, but after metamorphosis body size in all water bodies was similar . In water bodies with 4 ppt salt, the abundance of dwarf tree frogs (Litoria fallax), dragonfly larvae, and damselfly larvae was lower than in water bodies with 0 and 2 ppt salt, which could have knock-on effects for community structure. Based on our results, salt may be an effective field-based B. dendrobatidis mitigation tool for lentic amphibians that could contribute to the conservation of numerous susceptible species. However, as in all conservation efforts, these benefits need to be weighed against negative effects on both target and nontarget organisms.
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Nova |
2015 |
Stockwell MP, Bower DS, Bainbridge L, Clulow J, Mahony MJ, 'Island provides a pathogen refuge within climatically suitable area', Biodiversity and Conservation, (2015) [C1]
Surveillance of pathogens can lead to significant advances towards making effective decisions in research and management for species threatened by disease. Batrachochytrium dendro... [more]
Surveillance of pathogens can lead to significant advances towards making effective decisions in research and management for species threatened by disease. Batrachochytrium dendrobatidis has been a major contributing factor to the global decline of amphibians. Knowledge of the distribution of B. dendrobatidis can contribute to understanding patterns of species decline and prioritizing action. Therefore, we surveyed four spatially distinct populations of a B. dendrobatidis susceptible species, the green and golden bell frog (Litoria aurea), for evidence of infection in the population. Three mainland populations were infected at a prevalence of 3.5¿28.3 %, with median infection loads of 0.28¿627.18 genomic equivalents (GE). Conversely, we did not detect infection in an island population 3 km from the mainland; the isolation and infrequent visitation of the island suggests that the pathogen has not arrived. Management actions for B. dendrobatidis and conservation of susceptible frog species are heavily dependent on the presence and absence of the pathogen in the population. Prevention of the accidental introduction of B. dendrobatidis and safe guarding genetic diversity of L. aurea is necessary to preserve unique diversity of the island population, whereas containment and control of the pathogen can be directed towards mainland populations. Knowledge of disease dynamics also provides a context to understand the ecology of remaining populations as variation in the physiology or habitat of the mainland populations have facilitated persistence of these populations alongside B. dendrobatidis. Other islands should be a priority target in disease surveillance, to discover refuges that can assist conservation.
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Nova |
2015 |
Stockwell MP, Clulow J, Mahony MJ, 'Evidence of a salt refuge: chytrid infection loads are suppressed in hosts exposed to salt', Oecologia, 177 901-910 (2015) [C1]
With the incidence of emerging infectious diseases on the rise, it is becoming increasingly important to identify refuge areas that protect hosts from pathogens and therefore prev... [more]
With the incidence of emerging infectious diseases on the rise, it is becoming increasingly important to identify refuge areas that protect hosts from pathogens and therefore prevent population declines. For the chytrid fungus Batrachochytrium dendrobatidis, temperature and humidity refuge areas for amphibian hosts exist but are difficult to manipulate. Other environmental features that may affect the outcome of infection include water quality, drying regimes, abundance of alternate hosts and isolation from other hosts. We identified relationships between water bodies with these features and infection levels in the free-living hosts inhabiting them. Where significant relationships were identified, we used a series of controlled experiments to test for causation. Infection loads were negatively correlated with the salt concentration of the aquatic habitat and the degree of water level fluctuation and positively correlated with fish abundance. However, only the relationship with salt was confirmed experimentally. Free-living hosts inhabiting water bodies with mean salinities of up to 3.5 ppt had lower infection loads than those exposed to less salt. The experiment confirmed that exposure to sodium chloride concentrations >2 ppt significantly reduced host infection loads compared to no exposure (0 ppt). These results suggest that the exposure of amphibians to salt concentrations found naturally in lentic habitats may be responsible for the persistence of some susceptible species in the presence of B. dendrobatidis. By manipulating the salinity of water bodies, it may be possible to create refuges for declining amphibians, thus allowing them to be reintroduced to their former ranges.
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Nova |
2015 |
Garnham JI, Stockwell MP, Pollard CJ, Pickett EJ, Bower DS, Clulow J, Mahony MJ, 'Winter microhabitat selection of a threatened pond amphibian in constructed urban wetlands', Austral Ecology, 40 816-826 (2015) [C1]
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Nova |
2015 |
Valdez JW, Stockwell MP, Klop-Toker K, Clulow S, Clulow J, Mahony MJ, 'Factors driving the distribution of an endangered amphibian toward an industrial landscape in Australia', Biological Conservation, 191 520-528 (2015) [C1]
Although human-modified habitats often result in a loss of biodiversity, some have been found to serve as habitat refuges for threatened species. Given the globally declining stat... [more]
Although human-modified habitats often result in a loss of biodiversity, some have been found to serve as habitat refuges for threatened species. Given the globally declining status of amphibians, understanding why some species are found in heavily modified environments is of considerable interest. We used the endangered green and golden bell frog (. Litoria aurea) as a model to investigate the factors influencing their distribution toward industrial areas within a landscape. The number of permanent waterbodies within a kilometer of surveyed sites was the best predictor of L. aurea occupancy, abundance and reproduction. It appears that industrial activities, such as dredging and waste disposal inadvertently created refuge habitat for L. aurea to fortuitously persist in a heavily modified landscape. Future conservation plans should mimic the positive effects of industrialization, such as increasing the number of permanent waterbodies, especially in areas containing ephemeral or isolated waterbodies and threatened with drought. Our findings also suggest that despite amphibians being relatively small animals, some species may require a larger landscape than anticipated. Recognizing life history traits, in combination with a landscape-based approach toward species with perceived limited motility, may result in more successful conservation outcomes. Identifying why threatened species persist in heavily disturbed landscapes, such as industrial sites, can provide direction toward future conservation efforts to prevent and reverse their decline.
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Nova |
2015 |
Bainbridge L, Stockwell M, Valdez J, Klop-Toker K, Clulow S, Clulow J, Mahony M, 'Tagging tadpoles: retention rates and impacts of visible implant elastomer (VIE) tags from the larval to adult amphibian stages', HERPETOLOGICAL JOURNAL, 25 133-140 (2015) [C1]
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Nova |
2015 |
James MS, Stockwell MP, Clulow J, Clulow S, Mahony MJ, 'Investigating behaviour for conservation goals: Conspecific call playback can be used to alter amphibian distributions within ponds', Biological Conservation, 192 287-293 (2015) [C1]
Conspecific attraction can prevent occupancy of restored or created habitats by limiting dispersal to unoccupied areas. This may cause problems for threatened taxa where habitat r... [more]
Conspecific attraction can prevent occupancy of restored or created habitats by limiting dispersal to unoccupied areas. This may cause problems for threatened taxa where habitat restoration and creation programmes are implemented as part of species recovery plans. Studies on birds have found that the introduction of artificial communication cues such as calling can increase occupancy of restored habitat. The endangered green and golden bell frog (Litoria aurea) has a number of behavioural traits which suggest conspecific attraction occurs via a vocal mechanism, including a loud conspicuous call and large chorusing aggregations. To date, attempts to repopulate restored and created habitat through natural immigration and active translocation of tadpoles and juveniles have been met with limited success for this species. We used L. aurea to determine if distribution could be manipulated via conspecific attraction using artificial communication cues. We placed speaker systems in uninhabited areas of five inhabited ponds across two locations and broadcast calls of L. aurea to see if we could manipulate distribution into previously unoccupied pond areas. Surveys undertaken before and after broadcast indicate that we successfully manipulated L. aurea distribution for adults increasing both occupancy and calling around the speaker locations. This occurred in four of five replicate ponds over three months of experimental treatment, but controls remained low in abundance. We suggest that manipulation of distribution via conspecific attraction mechanisms could be a useful conservation tool for endangered amphibian habitat restoration and creation programmes, resulting in increased occupancy and programme success.
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Nova |
2014 |
Sanders M, Clulow S, Bower D, Clulow J, Mahony J, 'Predator presence and vegetation density affect capture rates and detectability of aquatic vertebrates: wide-ranging implications for a common survey technique.', Proceedings of the 38th Meeting of the Australian Society of Herpetologists, 47-47 (2014) [O1]
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2014 |
Pizzatto L, Stockwell M, Clulow S, Clulow J, Mahony M, 'Chemical communication in green and golden bell frogs: do tadpoles respond to chemical cues from dead conspecifics?', Chemoecology, (2014) [C1]
Captive bred animals often lack the ability of predator recognition and predation is one of the strongest causes of failure of breed and release projects. Several tadpole and fish... [more]
Captive bred animals often lack the ability of predator recognition and predation is one of the strongest causes of failure of breed and release projects. Several tadpole and fish species respond defensively to chemical cues from injured or dead conspecifics, often referred to as alarm pheromones. In natural conditions and in species that school, the association of chemical cues from predators to alarm pheromones released by attacked conspecifics may lead to the learning of the predator-related danger without experiencing an attack. In the laboratory, this chemical communication can also be used in associative learning techniques to teach naïve tadpoles to avoid specific predators and improve survivorship of released animals. In our experimental trials, tadpoles of the threatened green and golden bell frog (Litoria aurea) did not avoid or decrease their activity when exposed to solutions of conspecific macerate, suggesting that the chemicals released into the water by dead/injured conspecifics do not function as an alarm pheromone. This non-avoidance of dead conspecific chemicals may explain why green and golden bell frog tadpoles have seemingly not developed any avoidance behaviour to the presence of introduced mosquito fish, and may render attempts to teach naïve tadpoles to avoid this novel predator more difficult. © 2014 Springer Basel.
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2014 |
Pickett EJ, Stockwell MP, Bower DS, Pollard CJ, Garnham JI, Clulow J, Mahony MJ, 'Six-year demographic study reveals threat of stochastic extinction for remnant populations of a threatened amphibian', Austral Ecology, 39 244-253 (2014) [C1]
Sustained demographic studies are essential for early detection of species decline in time for effective management response. A paucity of such background data hindered the potent... [more]
Sustained demographic studies are essential for early detection of species decline in time for effective management response. A paucity of such background data hindered the potential for successful conservation during the global amphibian decline and remains problematic today. The current study analysed 6 years of mark-recapture data to determine the vital demographic rates in three habitat precincts of the threatened frog, Litoria aurea (Hylidae) and to understand the underlying causes of variability in population size. Variability in population size of L.aurea was similar to many pond-breeding species; however this level of fluctuation is rare among threatened amphibians. Highly variable populations are at greater risk of local extinction and the low level of connectivity between L.aurea populations means they are at a greater risk of further decline due to stochastic extinction events and incapacity to recolonize distant habitat. We recommend that management of this species should encourage recolonization through creation of habitat corridors and reintroduction of L.aurea to areas where stochastic extinction events are suspected. © 2013 Ecological Society of Australia.
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2014 |
Nixon B, Ewen KA, Krivanek KM, Clulow J, Kidd G, Ecroyd H, Jones RC, 'Post-testicular sperm maturation and identification of an epididymal protein in the Japanese quail (Coturnix coturnix japonica)', REPRODUCTION, 147 265-277 (2014) [C1]
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2014 |
Bower DS, Pickett EJ, Garnham JI, Deboo ML, McCurry MR, Mengerink RM, et al., 'Diet of a threatened pond frog differs over a small spatial scale', Endangered Species Research, 23 93-98 (2014) [C1]
Suitability of habitat patches affects demographic processes and consequently influences the viability of populations. In order for managers to consider the potential of resources... [more]
Suitability of habitat patches affects demographic processes and consequently influences the viability of populations. In order for managers to consider the potential of resources on a scale appropriate to their use, it is important to understand the processes that influence the ecology of threatened species. Differential growth rates of Litoria aurea (green and golden bell frog) at Sydney Olympic Park, Australia, may be explained by prey availability and diet. We tested: (1) whether food availability differed among precincts at Sydney Olympic Park and (2) whether the diet of L. aurea was influenced by availability of invertebrate prey. Diets were distinct among precincts and reflected the variation in biomass and richness of invertebrate assemblages. Precincts with greater biomass corresponded to areas with faster individual growth rates and greater habitat structure. The differences in diet and individual growth rates of L. aurea among precincts at Sydney Olympic Park demonstrate how caution must be applied to generalising population function, even within a small area.
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2014 |
Bower DS, Pickett EJ, Stockwell MP, Pollard CJ, Garnham JI, Sanders MR, et al., 'Evaluating monitoring methods to guide adaptive management of a threatened amphibian ( Litoria aurea)', ECOLOGY AND EVOLUTION, 4 1361-1368 (2014) [C1]
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2014 |
Clulow J, Trudeau VL, Kouba AJ, 'Amphibian declines in the twenty-first century: Why we need assisted reproductive technologies', Advances in Experimental Medicine and Biology, 753 275-316 (2014)
Each amphibian species is evolutionarily distinct, having developed highly specialized and diverse reproductive strategies in both terrestrial and aquatic environments. These uniq... [more]
Each amphibian species is evolutionarily distinct, having developed highly specialized and diverse reproductive strategies in both terrestrial and aquatic environments. These unique reproductive patterns and mechanisms, key to species propagation, have only been explored in a limited number of laboratory models. Although the development of applied reproductive technologies for amphibians has proven useful for a few threatened species, the real benefit of this technology has been new insights into the reproductive adaptations, behavior, endocrinology, and physiological mechanisms that have evolved over millions of years. As the basic fundamental database on amphibian reproductive physiology has grown, so has the applied benefit for species conservation. In particular, technologies such as non-invasive fecal and urinary hormone assays, hormone treatments for induced breeding or gamete collection, in vitro fertilization, and the ability to establish genome resource banks have all played important roles in monitoring or managing small populations of captive species. Amphibians have the ability to produce a large excess of germplasm (up to 10,000 ovulated eggs in a single reproductive event) that if not collected and preserved, would represent a wasted valuable resource. We discuss the current state of knowledge in assisted reproductive technologies for amphibians and why their extinction crisis means these available tools can no longer be implemented as small-scale, last-ditch efforts. The reproductive technologies must be established early as a key component of large-scale species recovery. © 2014 Springer Science+Business Media New York.
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2013 |
Pickett EJ, Stockwell MP, Bower DS, Garnham JI, Pollard CJ, Clulow J, Mahony MJ, 'Achieving no net loss in habitat offset of a threatened frog required high offset ratio and intensive monitoring', BIOLOGICAL CONSERVATION, 157 156-162 (2013) [C1]
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2013 |
Kouba AJ, Lloyd RE, Houck ML, Silla AJ, Calatayud N, Trudeau VL, et al., 'Emerging trends for biobanking amphibian genetic resources: The hope, reality and challenges for the next decade', BIOLOGICAL CONSERVATION, 164 10-21 (2013) [C3]
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2013 |
Bower DS, Stockwell MP, Pollard CJ, Pickett EJ, Garnham JI, Clulow J, Mahony MJ, 'Life stage specific variation in the occupancy of ponds by Litoria aurea, a threatened amphibian', Austral Ecology: a journal of ecology in the Southern Hemisphere, 38 543-547 (2013) [C1]
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2013 |
Mahony MJ, Hamer AJ, Pickett EJ, McKenzie DJ, Stockwell MP, Garnham JI, et al., 'Identifying Conservation and Research Priorities in the Face of Uncertainty: A Review of the Threatened Bell Frog Complex in Eastern Australia.', Herpetological Conservation and Biology, 8 519-538 (2013) [C1]
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2013 |
Lawson B, Clulow S, Mahony MJ, Clulow J, 'Towards Gene Banking Amphibian Maternal Germ Lines: Short-Term Incubation, Cryoprotectant Tolerance and Cryopreservation of Embryonic Cells of the Frog, Limnodynastes peronii', PLOS ONE, 8 (2013) [C1]
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2012 |
Pickett EJ, Stockwell MP, Pollard CJ, Garnham JI, Clulow J, Mahony MJ, 'Estimates of sex ratio require the incorporation of unequal catchability between sexes', Wildlife Research, 39 350-354 (2012) [C1]
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2012 |
Clulow JR, Buss H, Evans G, Sieme H, Rath D, Morris L, Maxwell WMC, 'Effect of staining and freezing media on sortability of stallion spermatozoa and their post-thaw viability after sex-sorting and cryopreservation', Reproduction in Domestic Animals, 47 1-7 (2012) [C1]
Sex-sorted, frozen-thawed stallion spermatozoa remain out of reach of commercial horse breeders because of the low efficiency of the sex-sorting process and unacceptable fertility... [more]
Sex-sorted, frozen-thawed stallion spermatozoa remain out of reach of commercial horse breeders because of the low efficiency of the sex-sorting process and unacceptable fertility rates after insemination. Two experiments were designed to test the effects of alternative staining and freezing media to improve the viability of sex-sorted frozen-thawed stallion spermatozoa. Experiment 1 compared two freezing media, INRA 82® and a modified lactose-ethylenediaminetetraacetic acid (EDTA), for the cryopreservation of sex-sorted stallion spermatozoa. No significant differences between the two freezing media could be identified, suggesting that both cryodiluents would be suitable for incorporation into a sex-preselection protocol for stallion spermatozoa. Experiment 2 compared Kenney's modified Tyrode's (KMT) and Sperm TALP (Sp-TALP) as the staining and incubation medium for stallion spermatozoa prior to sex-sorting. A significant increase in the percentage of acrosome-reacted spermatozoa occurred after staining and incubation in the clarified Sp-TALP compared with KMT. As no improvements in sorting rates were achieved using Sp-TALP, it was concluded that stallion sorting protocols could include KMT as the staining and incubation medium while either INRA 82® or lactose-EDTA could be employed as a cryodiluents. © 2011 Blackwell Verlag GmbH.
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2012 |
Clulow J, Clulow S, Guo J, French AJ, Mahony MJ, Archer M, 'Optimisation of an oviposition protocol employing human chorionic and pregnant mare serum gonadotropins in the Barred Frog Mixophyes fasciolatus (Myobatrachidae)', Reproductive Biology and Endocrinology, 10 (2012) [C1]
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2012 |
Stockwell MP, Clulow J, Mahony MJ, 'Sodium chloride inhibits the growth and infective capacity of the amphibian chytrid fungus and increases host survival rates', PLoS One, 7 (2012) [C1]
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2010 |
Clulow JR, Evans G, Maxwell WMC, Morris LHA, 'Evaluation of the function of fresh and frozenthawed sex-sorted and non-sorted stallion spermatozoa using a heterologous oocyte binding assay', Reproduction, Fertility and Development, 22 710-717 (2010)
The aim of the present study was to evaluate the potential oocyte binding ability and functional integrity of fresh or frozenthawed, sex-sorted or non-sorted stallion spermatozoa.... [more]
The aim of the present study was to evaluate the potential oocyte binding ability and functional integrity of fresh or frozenthawed, sex-sorted or non-sorted stallion spermatozoa. In the absence of effective IVF procedures in the horse, a heterologous sperm-binding assay was used as an indicator of fertilising capacity to assess differences in the ability of stallion spermatozoa to bind to bovine oocytes. The functional integrity of four treatment groups was assessed: (1) fresh non-sorted spermatozoa; (2) fresh sex-sorted spermatozoa; (3) frozen-thawed non-sorted spermatozoa; and (4) frozen-thawed sex-sorted spermatozoa. Spermatozoa found in association with the zona pellucida of the bovine oocytes were deemed 'attached' or 'bound' depending on their characterisation as either acrosome intact or acrosome reacted, respectively. Significantly less frozen-thawed spermatozoa were found attached to the oocytes compared with fresh spermatozoa. No significant differences were identified between the number of attached sex-sorted and non-sorted frozen-thawed spermatozoa. However, significantly more sex-sorted than non-sorted fresh spermatozoa were found attached to the oocytes after 1 h coincubation, although after 3 h coincubation this difference was no longer apparent. In conclusion, sex-sorted fresh and frozen-thawed stallion spermatozoa are functionally capable of attaching and binding to bovine oocytes in vitro. Furthermore, fresh sex-sorted spermatozoa attach better than non-sorted spermatozoa, suggesting that they have a more advanced capacitation-like status. © 2010 CSIRO.
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2010 |
Stockwell MP, Clulow J, Mahony MJ, 'Efficacy of SYBR 14/propidium iodide viability stain for the amphibian chytrid fungus Batrachochytrium dendrobatidis', Diseases of Aquatic Organisms, 88 177-181 (2010) [C1]
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2010 |
Stockwell MP, Clulow J, Mahony MJ, 'Host species determines whether infection load increases beyond disease-causing thresholds following exposure to the amphibian chytrid fungus', Animal Conservation, 13 62-71 (2010) [C1]
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2009 |
Clulow JR, Evans G, Morris LHA, Maxwell WMC, 'Factors influencing the "sortability" of stallion spermatozoa into X- and Y-chromosome bearing populations', Animal Reproduction Science, 113 220-228 (2009)
Intrinsic differences between stallions exist for semen traits such as motility, morphology fertility and the ability of spermatozoa to survive cryopreservation processes. Ejacula... [more]
Intrinsic differences between stallions exist for semen traits such as motility, morphology fertility and the ability of spermatozoa to survive cryopreservation processes. Ejaculates from 11 stallions were used to test the differences between stallions when selecting X- and Y-chromosome bearing spermatozoa using a modified flow cytometer. Data on orientation and viability of spermatozoa were collected during sex-sorting, and motility characteristics of sex-sorted and non-sorted (control) spermatozoa were assessed before and after cryopreservation. An index was created to rank each stallion in order of their suitability for sex-sorting using the data generated by the flow cytometry software. Motility of spermatozoa was higher after sorting and cooling than in the fresh ejaculates, but was significantly lower after thawing in comparison to fresh semen for both sex-sorted and non-sorted spermatozoa. Semen samples with a high percentage of food dye positive, defined as dead, spermatozoa had a low sortability index and ranking. Thus, percentage of dead spermatozoa in the semen sample was identified as the most important factor determining sortability. We conclude that variation between stallions exists for the sortability of their spermatozoa and that the sortability index is a useful tool for the selection of suitable stallions for a sex-sorting program. Crown Copyright © 2008.
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2008 |
Clulow JR, Mansfield LJ, Morris LHA, Evans G, Maxwell WMC, 'A comparison between freezing methods for the cryopreservation of stallion spermatozoa', Animal Reproduction Science, 108 298-308 (2008)
The effects of sperm freezing concentration (40 × 106 mL-1 vs. 400 × 106 mL-1), straw size (0.25 mL vs. 0.5 mL) and freezing method (liquid nitrogen vapour in a Styrofoam® box vs.... [more]
The effects of sperm freezing concentration (40 × 106 mL-1 vs. 400 × 106 mL-1), straw size (0.25 mL vs. 0.5 mL) and freezing method (liquid nitrogen vapour in a Styrofoam® box vs. programmable freezing machine) were evaluated in a 2 × 2 × 2 factorial experimental design using 3 split ejaculates from each of 4 stallions. Immediately after thawing, the total motility and forward progressive motility of spermatozoa frozen at a concentration of 40 × 106 mL-1 was higher than for spermatozoa frozen at 400 × 106 mL-1. No significant differences were observed in the semen parameters assessed after cryopreservation in either 0.25 or 0.5 mL straws. However, the programmable freezer provided a more consistent and reliable freezing rate than liquid nitrogen vapour. We conclude that an effective protocol for the cryopreservation of stallion spermatozoa at low concentrations would include concentrations of 40 × 106 mL-1 in 0.25 mL straws using a programmable freezer. This freezing protocol would be suitable for emerging sperm technologies such as sex-preselection of stallion spermatozoa as the sorting process yields only low numbers of spermatozoa in a small volume available for either immediate insemination or cryopreservation. © 2007 Elsevier B.V. All rights reserved.
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2008 |
Clulow JR, Buss H, Sieme H, Rodger JA, Cawdell-Smith AJ, Evans G, et al., 'Field fertility of sex-sorted and non-sorted frozen-thawed stallion spermatozoa', Animal Reproduction Science, 108 287-297 (2008)
In the 2004/2005 breeding season, the fertility of sex-sorted (SS) and non-sorted (NS) frozen stallion spermatozoa from two Hannovarian stallions was compared. A hysteroscopic ins... [more]
In the 2004/2005 breeding season, the fertility of sex-sorted (SS) and non-sorted (NS) frozen stallion spermatozoa from two Hannovarian stallions was compared. A hysteroscopic insemination technique [Morris, L.H., Tiplady, C., Allen, W.R., 2003a. Pregnancy rates in mares after a single fixed time hysteroscopic insemination of low numbers of frozen-thawed spermatozoa onto the uterotubal junction. Equine Vet. J. 35, 197-201] was used to deposit low doses (6, 13 or 25 × 106 frozen-thawed SS or NS spermatozoa) onto the utero-tubal junction at 32 or 38 h after the administration of Chorulon (2500 IU, Intervet). Fertility was low, with one pregnancy (13 × 106 spermatozoa, 500 µL) obtained after artificial insemination with frozen SS spermatozoa (n = 29 cycles) which resulted in the birth of a filly. Two pregnancies were obtained in mares inseminated with 6 × 106 NS spermatozoa in 250 µL (n = 31 cycles). Mares failing to conceive on two experimental cycles were allocated to the conventional insemination group. Insemination with >500 × 106 motile NS frozen-thawed spermatozoa, yielded satisfactory per cycle conception rates (35.5%, 22/62) for both stallions combined and was within the values of their normal fertility as quoted by the stud's records. This suggests that the quality of the frozen semen was acceptable and that the freezing processes yielded viable spermatozoa capable of fertilisation. The poor fertility after hysteroscopic insemination with low doses of sex-sorted or non-sorted spermatozoa from the same stallions may be directly attributable to the low dose insemination conditions with frozen-thawed rather than sex-sorted spermatozoa. © 2007 Elsevier B.V. All rights reserved.
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2008 |
Stockwell MP, Clulow S, Clulow J, Mahony MJ, 'The impact of the amphibian Chytrid Fungus Batrachochytrium dendrobatidis on a Green and Golden Bell Frog Litoria aurea reintroduction program at the Hunter Wetlands Centre Australia in the Hunter Region of NSW', Australian Zoologist, 34 379-386 (2008) [C1]
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2007 |
Fitzsimmons C, McLaughlin EA, Mahony MJ, Clulow J, 'Optimisation of handling, activation and assessment procedures for Bufo marinus spermatozoa', Reproduction, Fertility and Development, 19 594-601 (2007) [C1]
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2007 |
Clulow JR, Maxwell WMC, Evans G, Morris LHA, 'A comparison of duck and chicken egg yolk for cryopreservation of stallion sperm', Australian Veterinary Journal, 85 232-235 (2007)
Duck and chicken egg yolk were compared for their protective effects against cold shock during the cryopreservation of stallion sperm in a lactose-EDTA-glycerol cryodiluent. A com... [more]
Duck and chicken egg yolk were compared for their protective effects against cold shock during the cryopreservation of stallion sperm in a lactose-EDTA-glycerol cryodiluent. A completely randomised design was used. Ejaculates from five stallions (n = 14 ejaculates) were split and diluted to either 20 or 200 × 106 sperm/mL in a lactose-EDTA extender containing either duck or chicken egg yolk. The extended semen was then frozen in liquid nitrogen. The percentage of sperm total motility and forward progressive motility were assessed before freezing and at 0 and 1 hr after thawing. Morphology data were also collected at 0 and 1 hr post thaw. Total and forward progressive motility were higher when the sperm were frozen in the presence of duck rather than chicken egg yolk. Furthermore, the total and forward progressive motility and percentage of morphologically normal sperm were higher when frozen at a concentration of 200 than 20 × 106/mL. The results of this study demonstrate that the motility parameters of stallion sperm are improved when the semen is frozen in lactose EDTA extender supplemented with duck egg yolk rather than chicken egg yolk. Moreover, sperm motility and the percentage of morphologically normal sperm were higher after freezing at a concentration of 200 × 106/ml rather than 20 × 106/ml. © 2007 Australian Veterinary Association.
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2005 |
Buss H, Clulow J, Sieme H, Maxwell WM, Morris LH, Sieg B, et al., 'Improvement of the freezability of sex-sorted stallion spermatozoa.', Animal reproduction science, 89 315-318 (2005)
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2004 |
Clulow J, Jones RC, 'Composition of Luminal Fluid Secreted by the Seminiferous Tubules and After Reabsorption by the Extratesticular Ducts of the Japanese Quail, Coturnix coturnix japonica', Biology of Reproduction, 71 1508-1516 (2004) [C1]
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Nova |
2004 |
Hansen LA, Dacheux F, Man SY, Clulow J, Jones RC, 'Fluid Reabsorption by the Ductuli Efferentes Testis of the Rat Is Dependent on Both Sodium and Chlorine', Biology of Reproduction, 71 410-416 (2004) [C1]
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2004 |
Edwards DL, Mahony MJ, Clulow J, 'Effect of sperm concentration, medium osmolality and oocyte storage on artificial fertilisation success in a myobatrachid frog (Limnodynastes tasmaniensis)', Reproduction Fertility and Development, 16 347-354 (2004) [C1]
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Nova |
2003 |
Man SY, Clulow J, Jones RC, 'Signal Transduction in the Ductuli Efferentes Testis of the Rat: Inhibition of Fluid Reabsorption by Cyclic Adenosine 3', 5' - Monophosphate', Biology of Reproduction, 1714-1718 (2003) [C1]
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Nova |
2002 |
Browne RK, Mahony MJ, Clulow J, 'A comparison of sucrose, saline, and saline with egg-yolk diluents on the cryopreservation of cane toad (Bufo marinus) sperm', Cryobiology, 44 251-257 (2002) [C1]
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2002 |
Browne RK, Clulow J, Mahony M, 'The effect of saccharides on the post-thaw recovery of cane toad (Bufo marinus) spermatozoa', CRYOLETTERS, 23 121-128 (2002)
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2002 |
Browne RK, Clulow J, Mahony MJ, 'The short-term storage and cryopreservation of spermatozoa from hylid and myobatrachid frogs', Cryo Letters, 23 129-136 (2002) [C1]
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Nova |
2002 |
Browne RK, Davis J, Pomering M, Clulow J, 'Storage of cane toad (Bufo marinus) sperm for 6 days at 0 degrees C with subsequent cryopreservation', Reproduction, Fertility and Development, 14 267-273 (2002) [C1]
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2001 |
Browne RK, Clulow J, Mahony MJ, 'Short-term storage of cane toad (Bufo marinus) gametes', Reproduction, 121 167-173 (2001) [C1]
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2000 |
Hansbro NG, Clulow J, Man SY, Jones RC, 'pH and bicarbonate in the ductuli efferentes testis of the rat', INTERNATIONAL JOURNAL OF ANDROLOGY, 23 46-50 (2000) [C1]
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Nova |
1999 |
Hansen LA, Clulow J, Jones RC, 'The role of Na+ -H+ exchange in fluid and solute transport in the rat efferent ducts', Experimental Physiology, 84 521-527 (1999) [C1]
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1999 |
HANSEN LA, CLULOW J, JONES RC, 'The role of Na+-H+ exchange in fluid and solute transport in the rat efferent ducts', Experimental Physiology, 84 521-527 (1999)
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1999 |
Murdoch RN, Armstrong VL, Clulow J, Jones RC, 'Relationship between motility and oxygen consumption of sperm from the cauda epididymides of the rat', Reproduction Fertility and Development, 11 87-94 (1999) [C1]
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1998 |
Browne RK, Clulow J, Mahony MJ, Clark AK, 'Successful recovery of motility and fertility of cryopreserved cane toad (Bufo marinus) sperm', Cryobiology, 37 339-345 (1998) [C1]
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Nova |
1997 |
Hansen LA, Clulow J, Jones RC, 'Perturbation of fluid reabsorption in the efferent ducts of the rat by testosterone propionate, 17 beta-oestradiol 3-benzoate, flutamide and tamoxifen', INTERNATIONAL JOURNAL OF ANDROLOGY, 20 265-273 (1997)
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1997 |
Man SY, Clulow J, Hansen LA, Jones RC, 'Adrenal independence of fluid and electrolyte reabsorption in the ductuli efferentes testis of the rat', EXPERIMENTAL PHYSIOLOGY, 82 283-290 (1997)
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1996 |
Clulow J, Hansen LA, Jones RC, 'In vivo microperfusion of the ductuli efferentes testis of the rat: Flow dependence of fluid reabsorption', EXPERIMENTAL PHYSIOLOGY, 81 633-644 (1996)
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1994 |
WANG S, JONES RC, CLULOW J, 'SURFACE-AREA OF APICAL AND BASOLATERAL PLASMALEMMA OF EPITHELIAL-CELLS OF THE DUCTULI EFFERENTES TESTIS OF THE RAT', CELL AND TISSUE RESEARCH, 276 581-586 (1994)
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1994 |
CLULOW J, JONES RC, HANSEN LA, 'MICROPUNCTURE AND CANNULATION STUDIES OF FLUID COMPOSITION AND TRANSPORT IN THE DUCTULI EFFERENTES TESTIS OF THE RAT - COMPARISONS WITH THE HOMOLOGOUS METANEPHRIC PROXIMAL TUBULE', EXPERIMENTAL PHYSIOLOGY, 79 915-928 (1994)
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1994 |
JONES RC, CLULOW J, 'INTERACTIONS OF SPERM AND THE REPRODUCTIVE DUCTS OF THE MALE TAMMAR WALLABY, MACROPUS-EUGENII (MACROPODIDAE, MARSUPIALIA)', REPRODUCTION FERTILITY AND DEVELOPMENT, 6 437-444 (1994)
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1994 |
ARMSTRONG VL, CLULOW J, MURDOCH RN, JONES RC, 'INTRACELLULAR SIGNAL-TRANSDUCTION MECHANISMS OF RAT EPIDIDYMAL SPERMATOZOA AND THEIR RELATIONSHIP TO MOTILITY AND METABOLISM', MOLECULAR REPRODUCTION AND DEVELOPMENT, 38 77-84 (1994)
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1992 |
CLULOW J, JONES RC, MURDOCH RN, 'MATURATION AND REGULATION OF THE MOTILITY OF SPERMATOZOA IN THE EPIDIDYMIS OF THE TAMMAR WALLABY (MACROPUS-EUGENII)', JOURNAL OF REPRODUCTION AND FERTILITY, 94 295-303 (1992)
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1992 |
CHATURAPANICH G, JONES RC, CLULOW J, 'ROLE OF ANDROGENS IN SURVIVAL OF SPERMATOZOA IN EPIDIDYMIS OF TAMMAR WALLABY (MACROPUS-EUGENII)', JOURNAL OF REPRODUCTION AND FERTILITY, 95 421-429 (1992)
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1992 |
CHATURAPANICH G, JONES RC, CLULOW J, 'PROTEIN-SYNTHESIS AND SECRETION BY THE EPIDIDYMIS OF THE TAMMAR WALLABY, MACROPUS-EUGENII (MACROPODIDAE, MARSUPIALIA)', REPRODUCTION FERTILITY AND DEVELOPMENT, 4 533-545 (1992)
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1990 |
SUJARIT S, JONES RC, SETCHELL BP, CHATURAPANICH G, LIN M, CLULOW J, 'STIMULATION OF PROTEIN SECRETION IN THE INITIAL SEGMENT OF THE RAT EPIDIDYMIS BY FLUID FROM THE RAM RETE TESTIS', JOURNAL OF REPRODUCTION AND FERTILITY, 88 315-321 (1990)
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1989 |
JONES RC, WALSH AL, SETCHELL BP, CLULOW J, 'GROWTH-FACTOR ACTIVITY IN LUMINAL FLUIDS FROM THE MALE REPRODUCTIVE-TRACT OF THE RAM, RAT, TAMMAR WALLABY (MACROPUS-EUGENII) AND JAPANESE QUAIL (COTURNIX-COTURNIX JAPONICA)', JOURNAL OF REPRODUCTION AND FERTILITY, 86 513-516 (1989)
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1988 |
CLULOW J, JONES RC, 'STUDIES OF FLUID AND SPERMATOZOAL TRANSPORT IN THE EXTRATESTICULAR GENITAL DUCTS OF THE JAPANESE QUAIL', JOURNAL OF ANATOMY, 157 1-11 (1988)
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1987 |
JONES RC, CLULOW J, 'REGULATION OF THE ELEMENTAL COMPOSITION OF THE EPIDIDYMAL FLUIDS IN THE TAMMAR, MACROPUS-EUGENII', JOURNAL OF REPRODUCTION AND FERTILITY, 81 583-590 (1987)
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1986 |
JONES RC, CLULOW J, STONE GM, SETCHELL BP, 'THE ROLE OF THE INITIAL SEGMENT OF THE EPIDIDYMIS (IS) IN SPERM MATURATION', DEVELOPMENT GROWTH & DIFFERENTIATION, 28 39-39 (1986) |
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1982 |
CLULOW J, JONES RC, 'PRODUCTION, TRANSPORT, MATURATION, STORAGE AND SURVIVAL OF SPERMATOZOA IN THE MALE JAPANESE QUAIL, COTURNIX-COTURNIX', JOURNAL OF REPRODUCTION AND FERTILITY, 64 259-266 (1982)
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