Archives of The Cold Blooded News

The Newsletter of the Colorado Herpetological Society

Volume 32, Number 7;   July, 2005

Sirens

by Jim Horton

Secretly wandering below the surface of ponds, ditches, and other slow moving waterways, lives an amphibian that most people are unaware of. It is an aquatic salamander with external gills and two tiny forelimbs just behind the head and lacking any rear limbs. It is sometimes referred to as an "eel" by those unfamiliar with its occurrence. It is able to make clicking, squeaking, faint whistling, and distress sounds such as yelping. It is the only known instance of deliberate sound production by salamanders Minton (2001). One species may reach lengths of three feet while its smaller cousin averages about eight inches. All are somewhat drab in color and strictly aquatic.

The salamanders in question are Sirens. They are a small group consisting of three species and several subspecies in two genera, Pseudobranchus and Siren.

The Dwarf sirens, Pseudobrachus, are a small species of the southeastern United States, rarely reaching ten inches in length. Dwarf siren subspecies (five in all) have longitudinal stripes and each foot has three digits.

The Greater siren Siren lacertina, occurs in the lower Atlantic costal plain and in Florida. It is the largest of the sirens, attaining lengths of over three feet.

Lesser sirens, Siren intermedia, occur in eastern Texas and Mississippi north to Illinois, Indiana, and barely reaching into Michigan. Greater and lesser sirens, unlike the dwarf sirens, have four toes on each limb.

Sirens may move over land to connect to other habitats. They also adapt to drought by retreating to crayfish tunnels or burrowing into mud. Another survival technique is to conserve water by producing a protective cocoon. The cocoon is derived from skin secretion glands and covers the entire body. Food items consist of a variety of invertebrates including crustaceans, insect larvae, snails, and earthworms. It will also consume small fish.

Siren eggs arc laid in the spring in small depressions in the bottom mud, and in some cases may be attended by the female Harding (1991). Egg numbers range from 200 to 500 or more. Tiny larvae will grow to maturity in about two years. Life expectancy is twenty years or more.

References:
Minton, S.A. Jr. (2001) Amphibians and Reptiles of Indiana, Indiana Academy of Science
Harding, J.H. (1997) Amphibians and Reptiles of the Great Lakes Region, University of Michigan Press
Conant, R. and Collins, J. (1991) Reptiles and Amphibians, Eastern/Central North America, 3rd ed. Houghton Mifflin