Crocodiles and alligators.

Abstract

This chapter discusses the taxonomy of crocodiles and alligators and their anatomical and physiological differences and the different ways in which crocodiles are living or kept. A great portion of this chapter tackles the anatomy, physiology, biochemistry and behaviour of crocodiles. The discussion on the anatomy of crocodiles includes the skeleton, skin, muscles, respiratory system, digestive system, urinary system, reproductive organs, endocrine organs, circulatory system and blood cells, nervous system and sensory organs, fat storage and eggs. The discussion on crocodilian physiology includes yolk sac resorption, sex differentiation, growth locomotion, digestion, normal oral flora, normal intestinal flora, respiration, excretion, responses to high salinity, reproduction, circulation, nervous activity, thermoregulation, immunity, inflammation, fever and diseases. Blood and urine biochemistry, mineral values, composition of crocodile fat, nutrient composition of crocodile eggs and paracloacal and gular glands are discussed in the section on biochemistry, while the topics covered under behaviour include embryonic learning, parental care, imprinting, dispersal of the young, cannibalism, hunting and feed selection, social behaviour, territoriality, sexual behaviour, nesting, thermoregulation and vocalization.

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

“…The significance of the combined presence of herpesvirus and Chlamydiaceae is unknown, but a similar situation has been noted in a herpesvirus investigation of Australian marsupials in which the presence of Chlamydia pecorum was a significant predictor of herpesvirus presence in 68 koalas (OR = 60). 37 In the literature, there is allusion to conjunctivitis being caused by Chlamydiaceae infection in Crocodylus niloticus in Africa, 15,16 C. porosus in Papua New Guinea, 17 and recently, C. siamensis in Thailand. 32 However, in all of these investigations, the diagnosis appears to be based primarily on identification of Chlamydiaceae in internal organs, most commonly the liver, because unlike the CP cases detailed in our study, the infections also involved internal organs.…”

“…The first syndrome to emerge was conjunctivitis and/or pharyngitis (CP). Chlamydiaceae bacteria have been noted in the literature as being associated with conjunctivitis in various Crocodylus spp., [15][16][17]32 and CP in saltwater crocodiles was initially attributed to this agent. However, the role of the bacterium became unclear when a survey on the prevalence of Chlamydiaceae in live saltwater crocodiles revealed a poor association between the syndrome and presence of the bacteria (Jerrett I .…”

High hatching success of saltwater crocodile (Crocodylus porosus) in a commercial Crocodile Farm of Bangladesh

“…Dehydration of eggs results in malformed hatchlings or premature death of the embryos. The incubation temperature not only determines the sex of hatchlings but also maintains body temperature of crocodiles in their later life (Huchzermeyer, 2003). A lack of fluid inside the eggs suggests that an egg is infertile or that the embryo died at an early stage.…”

Steatitis in wild sharptooth catfish, Clarias gariepinus (Burchell), in the Olifants and Lower Letaba Rivers in the Kruger National Park, South Africa

“…The condition has been described from many species of both warm and cold-blooded animals, associated with the feeding of rancid or unsaturated fats, often of fish origin, particularly in the absence of sufficient vitamin E (Fytianou, Koutinas, Saridomichelakis & Koutinas 2006;Goodwin 2006;Herman & Kircheis 1985;Murai & Andrews 1974;Roberts, Richards & Bullock 1979;Roberts & Agius 2008). Previously described cases of pansteatitis in crocodiles were associated with consumption of large numbers of dead and rancid fish consumed by farmed crocodiles (Huchzermeyer 2003). Larsen, Buergelt, Cardeilhac & Jacobson (1983) reported steatitis at slaughter in apparently healthy alligators fed an exclusive fish diet.…”