Illinois Natural History Survey - University of Illinois

Caudata       Siren intermedia -- Lesser Siren

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Purple shade indicates vouchered specimens. Light blue (cyan) shade indicates photographic records. Yellow shade indicates verified sighting. Slanted hatch indicates pre-1980 records only

NOTE: Not all specimens upon which these maps are based have been verified.

Key Characters: External gills; short front legs; no hind legs.

Similar Species: None.

Subspecies: Western lesser siren, S. i. nettingi.

Description: Named for mythological sea nymphs, sirens are long (up to 46 cm TL), slender brownish black or dark olive salamanders with small black spots and light spots. Belly lighter than back. Elongated body bears 34-37 costal grooves. Toothless jaws covered with dark, keratinized sheaths. Males and females indistinguishable externally. Larva differs from older individual by having more extensive tail fin and distinctive orange-red markings that include head stripe from gill to gill by way of snout, band across back of head, and stripe down middle of back.

Habitat: Aquatic and nocturnal inhabitants of swamps, ditches, lowland ponds, and sloughs.

Natural History: This permanently aquatic salamander burrows by day class="main"in debris and muck, but may remain active most of year. In seasonally dry bodies of water, they descend into burrows, produce a cocoon from skin gland secretions, and estivate until water returns. Adults eat worms, snails, and crayfish. Little is known about courtship and mating. Small larvae (about 24 mm TL) appear in May, grow quickly, and within a year some are 20 cm TL. Maturation probably requires 3-4 years. Underwater microphones have detected clicking sounds produced by sirens when they approach each other.

Status: May be even more widespread than thought, but infrequently seen because of secretive habits. Common in the southern quarter of the state and in places along the Illinois and Wabash rivers.


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