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Atrazine, an info disruptor, interferes with the olfaction of aquatic organisms by impairing the chemosensory system. Consequently, it affects behavior, physiology, and growth increases mortality and infections, and suppresses the immune system of aquatic animals. In this study, we wanted to determine the sensitivity of larval Euphlyctis cyanophlyctis to different concentrations of atrazine by assessing their antipredator behavior, growth, morphology, and metamorphic traits. The results indicate that exposure to atrazine did not affect the survival of tadpoles. However, it caused retarded growth at higher concentrations. Interestingly, the antipredator behavior of tadpoles toward conspecific alarm cues decreased in a dose‐dependent manner with an increase in the concentration of atrazine. Tadpoles exposed to low concentrations of atrazine had deeper, wider bodies and tails while those exposed to higher concentrations had shallower and narrower bodies with shallower tail muscles. However, at low and moderate concentrations atrazine did not affect size at metamorphosis, it extended the larval duration at higher concentrations. Research highlights: Atrazine (ATZ) disrupts innate predator recognition of larval skipper frogs.ATZ alters morphological traits of larval skipper frogs that are similar to those induced by predators.ATZ may increase predation risk in the larval anurans. [ABSTRACT FROM AUTHOR]

Glucocorticoids (GCs) are primarily involved in mobilising energy reserves to various physiological processes including reproduction. During situations of stress, GCs also help in coping with stress by diverting energy away from processes such as growth and reproduction. Hence, studying annual and seasonal changes in GCs of wild populations can help in understanding their role in stress management and reproduction. The quantification of GCs in wild animals involves capturing, handling and restraining, which could be stressful. Moreover, different species may exhibit differential sensitivity to different stressors. Hence, determining species-specific sensitivities and responses to different stressors may help in developing effective conservation measures. In this context, we studied the annual and seasonal variations in corticosterone metabolites of the Bombay night frog, Nyctibatrachus humayuni. In addition, the effects of handling, marking and short-term captivity (24 h) on corticosterone metabolite levels of N. humayuni were determined. Our results show that urinary corticosterone metabolites (UCM) varied significantly annually and between the sexes; in males, the levels were highest during the breeding season, whilst in females, the levels were highest just before the breeding season. Interestingly, UCM levels of both the sexes were not affected by tagging with visual implant elastomer (VIE), and by short-term captivity, suggesting that these manipulations were not stressful in terms of corticosterone responses. [ABSTRACT FROM AUTHOR]

Herpetological research involving amphibians is increasingly using mark and recapture methods, employing various techniques such as toe-clipping and visible implant alphanumeric tags. Visual Implant Elastomer (VIE) is a new method available for herpetological surveys, involving a coloured dye inserted into the epidermal skin surface of frogs. Previously, there has been only one study which demonstrated that the VIE method does not generate a significant physiological stress response (using a faecal glucocorticoid method) in a captive amphibian species. Physiological stress can also be quantified non-invasively using urinary corticosterone metabolite (UCM) enzyme-immunoassay in amphibians. In this study, we tested the physiological stress response of a common amphibian species, wild caught Asian toads (Duttaphrynus melanostictus), by comparing UCM responses to capture handling, sham control or VIE marking method. Adult males (n = 38) were captured and sampled for baseline UCM (t = 0 h) then marked either using the VIE or sham (saline control), or only handled during capture. Subsequently, urine samples were collected at t = 2, 12 and 24 h for toads within each group. UCM levels were quantified using an enzyme-immunoassay (EIA) to determine differences among treatment groups and over time following capture. Toads generated acute stress responses to all three groups, showing a change in UCMs between baseline samples, 12 h, and 24 h samples. The mean UCM levels were not significantly different between the VIE method and the control groups (capture handling or sham operated). These results indicate that VIE method of tagging is no more stressful than routine handling of amphibians, hence in this context, the method does not have any additional welfare implications. Future research should explore the limitations of VIE tagging for long-term mark recapture studies, however, our current findings support its application as a minimally-invasive method for marking amphibians. [ABSTRACT FROM AUTHOR]

ABSTRACT Gonadogenesis was studied in Microhyla ornata (Family: Microhylidae) and Hylarana malabarica (Family: Ranidae) up to sexual maturity. Indifferent gonads of M. ornata directly differentiated into either testes or ovaries while those of H. malabarica differentiated into ovaries in all the individuals followed by testicular differentiation in males through an ovarian phase. In some tadpoles of M. ornata, formation of a central cavity at Gosner stage 27 marked ovary differentiation while meiosis was initiated at stage 29. Folliculogenesis was evident at stage 39. Vitellogenesis was initiated in females 9 months post-metamorphosis that attained maturity around 11 months after the completion of metamorphosis. Gonads of males with uniformly distributed germ and somatic cells remained undifferentiated until stage 41. Germ and somatic cells reorganized into seminiferous cords at stage 42. One month after completing metamorphosis, testes contained seminiferous tubules while those of 3 months old males exhibited all spermatogenic stages. In H. malabarica, germ cells entry into meiosis marked ovary differentiation at stage 29 while, ovarian cavity was discernable around stage 35. Post-metamorphosis, ovaries of 1-6 month old females contained pre-diplotene oocytes. Females were immature even 1 year after the completion of metamorphosis. In all the tadpoles, ovaries with central cavity and meiocytes were present up to the completion of metamorphosis. Gonads of prospective males displayed an obliterating ovarian cavity along with degenerating oocytes at the end of metamorphosis. Germ and somatic cells reorganized into seminiferous cords in males 3 months after the completion of metamorphosis. Testes of 4 months old males exhibited distinct seminiferous tubules while those of 6 months old exhibited meiosis. All spermatogenic stages were observed in testes of 9 months old males indicating maturity. J. Exp. Zool. 323A: 666-678, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Describes the usefulness of endoscopy to determine the sex of small juvenile sea turtles and describes the sex ratio of pelagic juvenile Caretta caretta in the Indian Ocean waters of the Perth area in Western Australia. Impact of climatic conditions of nesting beaches on the sex ratios of nests; Methods to determine the sex of small juvenile sea turtles; Sex ratios of post-pelagic juvenile.