The lesser siren is an eel-like salamander with a long slender body (18-68 cm long) and a very small dorsal fin that runs down its back. It has only a pair of front legs; each foot has four toes. The front legs are very small. The head is flat, and there are bushy gills on each side of the head. Siren intermedia varies in color from light grayish to green to olive or black; there are also small dots that are visible on lighter colored sirens.
Siren intermedia, the Lesser Siren, ranges from the Coastal Plains of Virginia to Florida, and westward to southern Texas and northeastern Mexico. They extend northward in the Mississippi Valley to Illinois, Indiana, and southwestern Michigan.
Siren intermedia can be found in any slow and sluggish body of water that is shallow and with plenty of aquatic vegetation, including marshes, ponds, ditches, and canals. (Conant and Collins, 1998 (Expanded 3rd Ed.); Harding, 1997)
The mating behavior of Siren intermedia has never been observed. Eggs are laid by the females in early spring. They are deposited in shallow holes in the soft bottom of the water, usually areas with dense plant growth. In these shallow depressions the female will lay from 12 to over 300 eggs; the female may lay multiple clutches through out the season. Freshly laid eggs are dark brown and 2.5-3 mm in diameter. The hatchling larvae are about 1.1 cm in length. (Petranka 1998; Harding 1997) (Conant and Collins, 1998 (Expanded 3rd Ed.); Harding, 1997; Petranka, 1998)
Siren intermedia is a nocturnal species, which may help it avoid being eaten by diurnal predators such as fish and wading birds.(Petranka 1998) It spends the daylight period hidden in debris on the bottom of bodies of shallow water or burrowed in the mud and vegetation. In the case that the water dries up, Siren intermedia will burrow into the mud were it can survive for months. The siren's skin glands will secrete a substance that will dry and form a cocoon over the body (except for the mouth), protecting the siren from drying up until the water returns.
Lesser sirens are very vocal, which is unusual for a salamander. It communicates with clicks when other sirens are around and when disturbed or attacked by a predator it will emit a very shrill call (Harding 1997).
Siren intermedia feeds on aquatic invertebrates such as crustaceans, insect larvae, worms, and snails. They will also readily consume young amphibian larvae and their own eggs. Siren intermedia often feeds by gulping up large amounts of material at a time. Vegetable matter is sometimes found in their digestive tracts is probably eaten accidentally. (Harding, 1997; Petranka, 1998)
Lesser sirens have no real impact on humans.
Sirens are occasionally used for fish bait, but this species normally gets little attention from humans.
Siren intermedia is extremely rare and possibly extinct in Michigan but this species is not threatened over most of its range. Due to their sensitive skin and gills, sirens could easily be harmed by chemicals and pesticides in the water. Another factor that may affect the future of this species is habitat destruction and the filling in of wetlands.
Jesse Gabbard (author), Michigan State University, James Harding (editor), Michigan State University.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends.
a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.
an animal that mainly eats meat
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
animals that generate their own body heat through metabolic processes.
mainly lives in water that is not salty.
animals that have little or no ability to regulate their body temperature, body temperatures fluctuate with the temperature of their environment, often referred to as 'cold-blooded'.
An animal that eats mainly insects or spiders.
marshes are wetland areas often dominated by grasses and reeds.
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
eats mollusks, members of Phylum Mollusca
having the capacity to move from one place to another.
specialized for swimming
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Cogger, H., R. Zweifel. 1998, 2nd Ed.. Encyclopedia of Reptiles and Amphibians. San Diego, CA: Academic Press.
Conant, R., J. Collins. 1998 (Expanded 3rd Ed.). A Field Guide to Reptiles and Amphibians of Eastern and Central North America. New York, NY: Houghton Mifflin Company.
Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region. Ann Arbor: The University of Michigan Press.
Petranka, J. 1998. Salamanders of the United States and Canada. Washington D.C.: Smithsonian Institution Press.