Eastern Tiger salamander | |
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Several in captivity | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Subclass: | Lissamphibia |
Order: | Caudata |
Family: | Ambystomatidae |
Genus: | Ambystoma |
Species: | A. tigrinum |
Binomial name | |
Ambystoma tigrinum Green, 1825 |
The tiger salamander or eastern tiger salamander (Ambystoma tigrinum) is a North American species of mole salamander.
Tiger salamanders grow to a typical length of 6–8 in (15–20 cm) and a maximum of 14 in (36 cm) in length, particularly neotenic individuals. Adults are usually blotchy with grey, green, or black, and have large, lidded eyes. They have short snouts, thick necks, sturdy legs, and long tails. Their diets consist largely of small insects and worms, though it is not rare for an adult to consume small frogs and baby mice.
Adults are rarely seen in the open, and often live in burrows that are usually two feet from the surface. Tiger salamanders are almost entirely terrestrial as adults, and usually only return to the water to breed, but also they partly live in both land and water. Although tiger salamanders are terrestrial, they are good swimmers. Like all ambystomatids, they are extremely loyal to their birthplaces, and will travel long distances to reach them. However, a single tiger salamander has only a 50% chance of breeding more than once in its lifetime. Males nudge a willing female to initiate mating, and then deposit a spermatophore on the lake bottom. The female picks up the packet and deposits the now-fertilized eggs on vegetation. Large-scale captive breeding of tiger salamanders has not been accomplished, for unknown reasons.
The larva is entirely aquatic, and is characterized by large external gills and a prominent caudal fin that originates just behind the head, similar to the Mexican axolotl. Limbs are fully developed within a short time of hatching. Some larvae, especially in seasonal pools and in the north, may metamorphose as soon as feasible. These are known as small morph adults. Other larvae, especially in ancestral pools and warmer climates, may not metamorphose until fully adult size. These large larvae are usually known as waterdogs, and are used extensively in the fishing bait and pet trade. Some populations may not metamorphose at all, and become sexually mature while in their larval form. These are the neotenes, and are particularly common where terrestrial conditions are bad. They are also very hardy.