Biological Synopses of the Species 



A Summary of the Distribution and Biolocry of Sea 

 Turtles in the Western Atlantic (Peter C.H. 

 Pritchard) 



Much has been written about the sea turtle species in the 

 western Atlantic and the task of distilling this information into 

 a brief presentation is invidious Despite the remaining gaps in 

 our knowledge of sea turtles, especially in such areas as natal 

 beach imprinting, navigation mechanisms, or population dynamics, 

 an extraordinary amount of sea turtle research, both routine and 

 high technology, has been undertaken in the last decade or two 

 resulting in these fascinating animals becoming among the most 

 intensively studied of all reptiles. 



All but one of the living sea turtle species are allocated 

 to the family Cheloniidae. This family includes at least 27 

 fossil and entirely extinct genera but only five living genera. 

 The living species are almost all of wide distribution, together 

 encompassing the oceans of the world, and were formerly of great 

 abundance. Moreover, they have shown a great ability to persist 

 even in the face of intense exploitation by man. Even though 

 populations of all species have been significantly reduced in the 

 last century or two, no species has become extinct, and most 

 retain at least some large and healthy populations. Most of the 

 extinct sea turtle genera were in fact more specialized — and thus 

 less adaptable — than the living forms. Geographic isolation has 

 fostered much higher levels of speciation and subspeciation among 

 the freshwater and terrestrial chelonians than among the marine 

 forms living in a contiguous environment. 



The living sea turtle species include the leatherback 

 ( Dermochelys coriacea) , which is the only living representative 

 of the family Dermochelyidae; the loggerhead f Caretta caretta) ; 

 the hawksbill ( Eretmochelys imbricata) ; the olive ridley 

 ( Lepidochelys olivacea) ; Kemp's ridley ( Lepidochelys kempi ) ; the 

 green turtle ( Chelonia mydas) ; the black turtle (Chelonia 

 agassizii) ; and the f latback (Natator depressa) . The last seven 

 species are all representatives of the family Cheloniidae; all 

 but the last two are found in the western Atlantic region (the 

 black turtle is confined to the eastern Pacific, and the f latback 

 to the waters of northern Australia) . 



The Leatherback ( Dermochelvs coriacea) 



Morphology ; The leatherback is the largest of all living 

 turtle species, attaining a carapace length of 150-170 cm and a 

 weight that may occasionally exceed 500 kg. The shell structure 

 of this species is unique; instead of the keratinized scutes that 



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