Chapter 1 1 DERMOPHIS MEXICANUS
Mexican caecilian
Classification Order Gymnophiona, Family Caeciliidae.
Distribution Central America, from southern Mexico to Panama.
Identification The front of the head is pointed and triangular in shape. The eyes are covered by skin and a small tentacle which enhances the sense of smell is found in a depression below and in front of the eye. The limbs are absent and the relatively long, stocky body bears numerous and conspicuous annular rings. The tail is virtually nonexistent, the body ending in a blunt point. The back is grayish or olive-brown and the belly usually yellowish. There is a prominent yellow spot on the cloacal region. Total length: 16-24 in (40-60 cm).
Habitat Moist soils with plenty of ground litter.
Biology This worm-like amphibian is for the most part a burrower and surfaces only at night and on rainy days. It digs rapidly, hunting insects, termites, and earthworms in underground tunnels. Strong jaws and numerous small hooked teeth enable it to grasp and swallow prey. The species is viviparous, each female giving birth on the ground to 3-4 young, similar in all respects to the adults but only two inches long.
2 ICHTHYOPHIS GLUTINOSUS
Ceylonese caecilian
Classification Order Gymnophiona, Family Ichthyophiidae.
Distribution Sri Lanka.
Identification The head is oval and relatively small. The eyes are minute, covered by skin, but visible. A tiny finger-like, chemical-detecting tentacle is situated between the eye and nostril, near the edge of the upper lip. There are no limbs and the body displays 350-390 annular rings, very close to one another. The conical tail is very short. The color of the back is uniformly dark brown with a few violet tints, and the belly is somewhat paler. A yellow stripe extends along the flanks from head to tail. Total length: 12-16 in (3040 cm).
Habitat Muddy and swampy ground close to water.
Biology The species lives in tunnels, not too far from the surface, dug in the mud. Food consists mainly of earthworms and various arthropods. After mating, the female digs a burrow close to water and lays as many as 54 eggs there. She coils herself around the eggs until they hatch. The newborn larvae immediately head for nearby ponds or streams and remain there until they complete metamorphosis.
3 AMBYSTOMA MACULATUM
Spotted salamander
Classification Order Caudata, Family Ambystomatidae.
Distribution Eastern North America, from Ontario and Nova Scotia to Georgia and Texas.
Identification This salamander is black, blue-black or brownish, with two conspicuous irregular rows of round, yellow or orange spots which extend from head to tail. The underside is uniformly gray. The body is robust, with 12 distinct costal grooves on the sides. Total length: 6-9 3/4 in (15-25 cm). (9 3/4 in = record size.)
Habitat Deciduous woods close to small ponds and pools.
Biology The species spends most of its life underground. Adults move to the mouth of their tunnels at night or on particularly rainy days, to ambush earthworms and other passing small invertebrates. In winter or at the beginning of spring rains, sexually mature individuals migrate to ponds to breed. The females lay one or more masses containing about 50-100 eggs. The larvae hatch in 1-2 months.
4 AMBYSTOMA TIGRINUM
Tiger salamander
Classification Order Caudata, Family Ambystomatidae.
Distribution North America, from Canada to Mexico.
Identification Largest of the land-dwelling salamanders, it is stoutly built and has a broad head with small eyes. The back is dark brown or blackish, with numerous light patches, varying in shape and arrangement, but sometimes fused with one another to form transverse stripes. The sides of the body have 11-14 distinct costal grooves. The relatively long tail is compressed laterally. Total length: 6-14 in (15-35 cm).
Habitat Arid plains and pine barrens to wet meadows and mountain forests.
Biology Adults spend most of the day under plant detritus or in abandoned crayfish or mammal burrows. During the night, especially after heavy rainstorms, they leave their shelters and surface to look for small tasty prey such as earthworms and snails. Breeding occurs at the end of winter or in early spring in temporary pools or fishless waters. The females lay jelly-like masses of 50-100 eggs on submerged debris. The larvae hatch within about one month and undergo metamorphosis in the summer.
Copyright © 1989 by Arnoldo Mondadori Editore S.p.A., Milan English translation copyright © 1989 by Arnoldo Mondadori Editore S.p.A., Milan