Sirens and Dwarf Sirens: Sirenidae

Physical characteristics: In addition to having a long, tubular body, no hind legs, and very short front legs, lesser sirens have thirty-one to thirty-seven grooves along their sides, four toes, and three gill slits. They are 7 to 27 inches (18 to 69 centimeters) long. The head is broadly rounded when looked at from the top. Newly hatched larvae are densely black and have bright red bands across the tip of the snout, across the head, and on the body. Older lesser sirens may keep a pale snout band, but the other markings disappear. The adult color pattern appears to vary from place to place in the geographic range, but there is always a greenish to gray background color with different amounts of shimmery speckling. The clear fin on the young siren's back and tail becomes solid in older lesser sirens and is present only on the tail.

Lesser sirens eat almost any water animal they can catch and fit into their mouths. (Illustration by Joseph E. Trumpey. Reproduced by permission.)

Geographic range: Lesser sirens live in North America from the far northeastern part of Mexico north to the southwestern part of Michigan and east to Florida and the southeastern part of Virginia.

Habitat: Lesser sirens live in many types of still or slowly flowing water, such as swamps, ponds, and ditches.

Diet: Lesser sirens eat almost any water animal they can catch and fit into their mouths, including small crustaceans such as crayfish, worms, mollusks such as snails, insect larvae, and small fishes. Crustaceans (krus-TAY-shuns) are water-dwelling animals that have jointed legs and a hard shell but no backbone. Mollusks (MAH-lusks) are animals with a soft, unsegmented body that may or may not have a shell.

Behavior and reproduction: Lesser sirens spend all their time in the water. Large numbers of them may live in one place. These salamanders spend the daylight hours burrowed into the water bottom or near the water's edge. They look for food along the water bottom at night. They suck the prey into their mouths and swallow it whole.

Salamanders usually do not make a sound, but when bitten or forced from a hiding spot by another salamander, lesser sirens yelp. Lesser sirens placed in unfamiliar surroundings may make several types of sounds. If there is not enough oxygen in the water, these lesser sirens come to the surface to gulp air.

If their pond, ditch, or mud hole dries out, lesser sirens move into burrows at the bottom and wait for water. They make a cocoon by shedding their skin several times and become inactive until water returns. The gills do not work unless the salamander is underwater, and they become small nubs while the lesser siren is in its burrow and breathing with its lungs.

Female lesser sirens lay as many as fifteen hundred eggs in a nest at the water bottom. Scientists believe one of the parents guards the nest. Each egg is enclosed in four jelly envelopes. The eggs hatch forty-five to seventy-five days after being laid. At this point the larvae are about 0.4 inches (10 millimeters) long.

Scientists do not know how lesser sirens find their mates or how the eggs are fertilized (FUR-teh-lyzed). They have found that during the breeding season most lesser sirens large enough to reproduce have a number of bite marks on them that match the size of the mouth of this species. Scientists believe males and females may bite each other during mating or that males bite one another while fighting over females or over territory.

Lesser sirens and people: Lesser sirens have no known importance to people. Some people are afraid of these salamanders because they confuse them with amphiumas (AM-fee-yoo-muhs), which give a dangerous bite.

Conservation status: Lesser sirens are not considered threatened or endangered. ∎