Amphibian (Class XI / XII)

Grey foam-nest tree frog minimises the chance of overheating by turning white.

Newts are also used as bioindicators. They have thin, sensitive skin and evidence of their presence (or absence) can serve as an indicator of the health of the environment. Most species are highly sensitive to subtle changes in the pH level of the streams and lakes where they live. Because their skin is permeable to water, they absorb oxygen and other substances they need through their skin.

Tetrodotoxin is found in the skin of salamanders. It is a neurotoxin.

Necturus maculosus is known as the common mudpuppy.

African dwarf frog is a tongueless frog. It is also toothless and completely aquatic. It uses its webbed feet to shove food in its mouth and down its throat. It has a hyobranchial pump to draw or suck food into its mouth.

The parotids are located behind the ears of toads.

Toads possess warty (bumpy) skin that helps the animal in blending more effectively into its environment, by breaking up its visual outline.

Cynops pyrrhogaster (Japanese fire belly newt) can regenerate its eye lens 18 times over a period of 16 years and retain its structural and functional properties.

True toads possess Bidder's organ, which may have a role in reproduction.

Full neotany is seen in Ambystoma tigrinum (salamander). They become sexually mature in their larval form and retain lot of larval characteristics in the adult form.

Jacobson's organ is a patch of sensory cells within the main nasal chamber that detects heavy moisture-borne odour particles. Thus, it has olfactory function.

Western Ghats region is the center of caecilian diversity. Of the 26 described species of caecilians in India, 25 are endemic to Western Ghats.

Axolotl or neonatal salamander is known as the walking fish. Axolotls are unusual among amphibians as they reach adulthood without undergoing metamorphosis.

Caecilians use complete internal fertilisation as a mode of reproduction. The male caecilians have a long tube-like organ, the phallodeum, which is inserted into the cloaca of the female for two to three hours.

The ability of some amphibians to change their colour by expansion and contraction of pigment cells is called metachrosis.

This is the correct match. 
The fully aquatic Bornean flat-headed frog is the first frog known to lack lungs entirely.
The Lake Titicaca frog has adapted to survive in oxygen deficient water.
The Pacific tree frog (Pseudacris regilla) produces the onomatopoeic "ribbit" often heard in films.
Members of the West African genus Nimbaphrynoides are unique among frogs in that they are viviparous.