Among all the vertebrates (which possess the backbone), the class to hover on the land for the first time were Reptiles. They possess scales on the outer layer of their thick skin which is devoid of any feather or hair. Reptiles lay hard shelled eggs in dry places near water bodies, like sea beach. Due to unmatched adaptation, they can survive on the land and even in an arid zone too. On the other hand, the Amphibians, in spite of being the close relatives of Reptiles, need water to lay their eggs. reptile breeders
Reptiles are hypothermic (Cold blooded animals) and depend upon the external environment for their body temperature. Amphibians breathe by their gills while Reptiles have lungs to breathe. Among all the reptiles like snakes, alligators, lizards, turtles etc., only the turtles show the likelihood of Amphibians. They can survive both in water and on the land. Even some turtles can live in deserts too!
Till date, about 250 species of turtles are categorized under the order Chelonia. Among them the terrestrial ones are termed as ‘tortoises’, those which survive in water are called ‘turtles’, and terrapins are those which live in brackish water. They vary in size. Leatherback sea turtles are the biggest while teeny bog turtles are the smallest ones, while a tortoise may grow up to two meters!
They have both endo- and exoskeleton and the body is protected by a shield like shell. The upper part of it is called the carapace and the lower side is plastron. Tortoises have heavier shell while the aquatic turtles possess flat and light shell. Aquatic turtles need to surface for breathing, but can remain under water for several hours.
Turtles/tortoises/terrapins are generally timid and found around the reefs, coastal areas, bays, straits, rivers, lakes, and bogs. They nest on the beaches or the banks where they dig out holes and lay a number of eggs during winter season. Tortoises are grouped under the family Testudinidae and order Testudines. At night, a female turtle/tortoise lays 1 – 30 eggs in the nest and then covers them with soil, sand leaves, small branches, etc.
These unattended eggs take about 60 – 120 days to hatch and the hatchlings, after coming out of the shell, start their own life to live. Initially they depend upon the embryonic egg sac for the nutrition but after that start taking more nutritional foods like insects, worms etc.