In Hong Kong, the lizards are represented by members of six major families: geckoes (Gekkonidae), skinks (Scincidae), agamids (Agamidae), lacertids (Lacertidae), dibamids (Dibamidae) and monitor lizards (Varanidae). Lizards are the largest group of reptiles in the world, with more than 3,000 species of which only two are venomous. Apart from the five species of sea turtles (among which the Green Turtle, Chelonia mydas, would nest in Hong Kong), all other native turtles that occur in Hong Kong are semi-aquatic or aquatic species inhabiting freshwater streams and ponds. Hong Kong has no true tortoises which have legs entirely adapted to walking on land. Turtles are characterized by their outer hard, keratin shell that effectively protects the body against predators, although the Soft-shelled Turtles (family Trionychidae) have a soft shell adapted for life in water. In Hong Kong, members of the first two groups are represented, and the snakes and turtles comprise both terrestrial species and their marine counterparts (the sea snakes and sea turtles). They are classified under four orders: Testudines (Turtles and Tortoises), Squmata (Lizards and Snakes), Crocodylia (Crocodiles and Alligators) and Rhynchocephalia (Tuatara). Reptiles comprise members of distinctive morphology and life habits. ![]() ![]() They possess dry, keratin scales for protecting their body from water loss they have more advanced respiratory and blood circulatory systems which enable them to live a more active mode of terrestrial life and their ability to undertake internal fertilization, and the development of leathery shells for protecting eggs from desiccation, offer them an additional reproductive advantage on land. Compared with amphibians, reptiles developed various adaptations which greatly reduce their dependence on water. In evolutionary terms, reptiles were the first group of vertebrates that became truly capable of living on land.
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