FROGS:
The study of frogs is called Batracology, belonging to Class Amphibian of Phylum Chordata.
The most common species of frog found in India is Rana tigrina.
Frogs are cold blooded or poikilothermic, live both on land and in fresh water.
Frogs changes its body color while they are in grasses and on dry land to hide from their enemies (camouflage). This protective colouration is called mimicry.
To protect itself from the severe cold in winter and scorching heat in summer, frogs becomes inactive and enters into a state of dormancy (buries deep into the mud of the pond).
A state of dormancy in winter is called hibernation and in summer called aestivation.
Morphology of Frog:
The skin of frog is smooth and slippery due to the presence of mucus.
The color of the skin is generally olive green with dark irregular spots on dorsal surface. But on ventral surface the skin is pale yellow in color.
Frogs never drinks water but absorbs it through the skin to fulfill the needs of the body.
The body of frog consists of a head and trunk but neck and tail are absent.
Above the mouth i.e. tip of the snout bears a pair of external nostrils which open into internal nostrils.
Eyes are bulged and covered by thin transparent nictitating membrane that protects them while in water.
On either side of eyes a membranous tympanum (ear) receives sound vibrations.
The forelimbs and hind limbs help in swimming, walking, leaping and burrowing.
The hind limbs are longer and stronger ends in five digits. Forelimbs are shorter and weaker that ends in four digits
Feet have webbed digits that help in swimming.
Frog exhibit sexual dimorphism. Male frogs can be distinguished by the presence of sound producing vocal sacs and also have copulatory pad on the first digit of the forelimbs which are absent in female frog.

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