Crocodiles: Inside out: a guide To the crocodilians and their functional morph

Guide to crocodilians, designed to assist scientists, wildlife managers, crocodile farmers, tourist operators, conservationists, veterinarians, and others working with these reptiles. Provides extensive information on anatomy, including the crocodilian's skeletal, muscular, cardiovascular, respiratory, digestive, urogenital and nervous systems. Includes full-colour photos, appendixes, list of further reading, glossary and index

Thermally induced torpor in fullterm lizard embryos synchronizes hatching with ambient conditions

Eggs inside an underground nest have limited access to information about above-ground conditions that might affect the survival of emerging hatchlings. Our measurements of heart rates of embryos inside the intact eggs of montane lizards (Bassiana duperreyi, Scincidae) show that low temperatures induce torpor in fullterm embryos, but do not do so during earlier embryogenesis or later, post-hatching. Because above-ground conditions affect soil temperatures, this stage-dependent torpor effectively restricts hatching to periods of high ambient temperatures above ground. Torpor thus can function not only to synchronize activity with suitable environmental conditions during post-hatching life (as reported for many species), but also can occur in embryos, to synchronize hatching with above-ground conditions that facilitate successful emergence from the nest

Adapting to the unpredictable: reproductive biology of vertebrates in the Australian wet–dry tropics

In the wet–dry tropics of northern Australia, temperatures are high and stable year-round but monsoonal rainfall is highly seasonal and variable both annually and spatially. Many features of reproduction in vertebrates of this region may be adaptations to dealing with this unpredictable variation in precipitation, notably by (i) using direct proximate (rainfall-affected) cues to synchronize the timing and extent of breeding with rainfall events, (ii) placing the eggs or offspring in conditions where they will be buffered from rainfall extremes, and (iii) evolving developmental plasticity, such that the timing and trajectory of embryonic differentiation flexibly respond to local conditions. For example, organisms as diverse as snakes (Liasis fuscus, Acrochordus arafurae), crocodiles (Crocodylus porosus), birds (Anseranas semipalmata) and wallabies (Macropus agilis) show extreme annual variation in reproductive rates, linked to stochastic variation in wet season rainfall. The seasonal timing of initiation and cessation of breeding in snakes (Tropidonophis mairii) and rats (Rattus colletti) also varies among years, depending upon precipitation. An alternative adaptive route is to buffer the effects of rainfall variability on offspring by parental care (including viviparity) or by judicious selection of nest sites in oviparous taxa without parental care. A third type of adaptive response involves flexible embryonic responses (including embryonic diapause, facultative hatching and temperature-dependent sex determination) to incubation conditions, as seen in squamates, crocodilians and turtles. Such flexibility fine-tunes developmental rates and trajectories to conditions–-especially, rainfall patterns–-that are not predictable at the time of oviposition

Diagnostic investigation of new disease syndromes in farmed Australian saltwater crocodiles (Crocodylus porosus) reveals associations with herpesviral infection

Since 2006, 3 new disease syndromes have emerged in farmed saltwater crocodiles (Crocodylus porosus) in the Northern Territory of Australia. We describe the syndromes through a retrospective study of laboratory findings from 187 diagnostic cases submitted to Berrimah Veterinary Laboratories between 2005 and 2014. The first syndrome was characterized by conjunctivitis and/or pharyngitis (CP), primarily in hatchlings. Herpesviruses were isolated in primary crocodile cell culture, or were detected by PCR directly from conjunctiva or pharyngeal tissue, in 21 of 39 cases of CP (54%), compared with 9 of 64 crocodiles without the syndrome (14%, p < 0.0001). Chlamydiaceae were detected by PCR in conjunctiva or pharyngeal tissue of 55% of 29 CP cases tested, and of these, 81% also contained herpesvirus. The second syndrome occurred in juveniles and growers exhibiting poor growth, and was characterized histologically by systemic lymphoid proliferation and nonsuppurative encephalitis (SLPE). Herpesviruses were isolated or detected by PCR from at least 1 internal organ in 31 of 33 SLPE cases (94%) compared with 5 of 95 crocodiles without the syndrome (5%, p < 0.0001). The third syndrome, characterized by multifocal lymphohistiocytic infiltration of the dermis (LNS), occurred in 6 harvest-sized crocodiles. Herpesviruses were isolated from at least 1 skin lesion in 4 of these 6 cases. Although our study revealed strong associations between herpesvirus and the CP and SLPE syndromes, the precise nature of the role of herpesvirus, along with the pathogenesis and epidemiology of the syndromes, requires further investigation