The class Amphibia includes not only frogs and toads, but also salamanders and caecilians, says Rahul Alvares.
Photo: Rahul Alvares.
The word ‘amphibian’ conjures up an image of a four-legged, bulging-eyed, tailless, hopping animal, aka a frog! Frogs and toads certainly fit this description, and in all likelihood, will be the only kind of amphibian most people will ever see. They all belong to the order Anura (ancient Greek for ‘without tail’).
Interestingly, there are two other orders in the class Amphibia. The first one is known as Caudata (Latin for tail) and includes salamanders. Salamanders not only have a tail but legs as well, and they resemble lizards. The second one goes by the name Gymnophiona (Greek for ‘naked serpent’) and includes caecilians. Caecilians, being legless, resemble either large worms or eels.
Both, salamanders and caecilians, are rare to find as they lead extremely secretive lives in unique habitats. I have never seen a salamander in the wild. Only one species seems to exist in India and is known as the Himalayan newt.
The first caecilian I ever found was on a road in Amboli. Unfortunately, the animal had been squashed dead by an automobile. From its colours I identified it as a Beddome’s caecilian.
My second encounter proved to be much more fortunate, yielding me a Bombay caecilian in the Cotigao Wildlife Sanctuary in Goa during the heaviest rains of July. The little animal was actually spotted by a client of mine, Frank, at night outside the room we were staying in!
If I ever thought frogs were tricky to handle, this caecilian posed an altogether whole new level of difficulty. The 17 cm.– long amphibian was so slimy that it was impossible to hold onto! Photographing it turned out to be a nightmare with the animal not staying still for even a split second. It was obviously extremely uncomfortable and so we released it right where we found it immediately after taking a few photographs.
Of the 26 species of caecilians found in India, 25 are endemic. The Western Ghats is the ‘hotspot’ for caecilians with 20 species found here alone! These legless amphibians live in leaf litter, loose soil, under rocks and decaying wood, and generally feed on earthworms, termites, and larvae of insects.
Being burrowers, caecilians have a strong skull, and in many species the bones in the skull are reduced and fused together to provide extra rigidity and strength. In addition, caecilians have a pointed snout with a mouth lying recessed beneath the head. All these adaptations serve the burrowing amphibian well for a life underground.
Almost all caecilians use lungs to respire, but they often use their skin or mouth to supplement oxygen absorption. Like in snakes, the left lung is usually much smaller than the right one (an adaptation to serve a long tube-like body).
While caecilians in other parts of the world mostly give birth to live young, Indian species are all known to be oviparous (egg-laying). A female Bombay caecilian from Koyna was found in a burrow with 144 eggs!
All caecilians possess a pair of tentacles located between their eyes and nostrils. A distinct identifying feature of the Bombay caecilian is that its tentacles are closer to its lips than its eyes.
Unlike frogs, caecilians have small eyes covered by skin. Their eyes are able to do little more than differentiate between light and dark. The Bombay caecilian possesses distinct eyes surrounded by a light white ring.
Author: Rahul Alvares First appeared in: Sanctuary Cub, March 2015.