Dermophis mexicanus

Dermophis mexicanus
Conservation status
Vulnerable  (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Gymnophiona
Family:	Caeciliidae
Genus:	Dermophis
Species:	D. mexicanus
Binomial name
Dermophis mexicanus (Duméril & Bibron, 1841)

The Mexican burrowing caecilian (Dermophis mexicanus) is a species of limbless amphibian in the family Caeciliidae. It is found in Mexico and Central America, where it burrows under leaf litter and plant debris.

Description

The adult Mexican burrowing caecilian grows to a length of 30 to 50 centimetres (12 to 20 in). In general appearance it resembles a large earthworm. There are about one hundred transverse annular folds in the skin which give the appearance of segments. The head has a pointed snout, a single row of teeth in the lower jaw and two vestigial eyes covered with skin. There is a pair of protrusible tentacles between the eyes and the nostrils. The body is elongated and there are no limbs. The upper surface is dark grey and the under surface pale gray with darker markings on derping the annuli.

Distribution and habitat

The Mexican burrowing caecilian is found in Mexico, Guatemala, El Salvador, Honduras, Nicaragua and possibly Belize, mostly on the Atlantic side but also in some isolated parts of the Pacific slope. Its natural habitats are subtropical or tropical dry forests, moist lowland forests, moist montane forests, plantations, rural gardens and heavily degraded former forest. It is fossorial, living in damp loose soil and under leaf litter, logs and plant debris, often in banana and coffee plantations. It is found at altitudes of up to 1,200 metres (3,900 ft) above sea level.

Biology

The Mexican burrowing caecilian feeds on invertebrates including earthworms, termites, crickets, slugs and snails. It emerges onto the ground surface on nights with light rainfall and catches small prey that come within its reach. Larger individuals may eat mice and small lizards. It moves by internal concertina-like movements and by undulating the body from side to side.

This caecilian is viviparous. Fertilisation is internal and up to sixteen developing larvae subsist on the yolks of their eggs for three months. Then they develop rasping teeth and feed on maternal glandular secretions, scraping the inside of the oviduct to stimulate the production of these. When they emerge, after eleven months gestation, they are 10 to 15 centimetres (3.9 to 5.9 in) long. They then shed their larval teeth and rapidly grow a set of adult ones.

Status

The Mexican burrowing caecilian is listed as Vulnerable in the IUCN Red List of Threatened Species. This is because it is thought that numbers have declined by more than thirty percent over the last ten years. It has several disjunct populations and in areas where it used to be abundant it now seems to be less common, and the locations in which it is found seem to be fewer in number. It may be persecuted in some locations because it superficially looks like a snake.