, the Lesser Siren, ranges from the Coastal Plains of Virginia to Florida, then westward to southern Texas and northeastern Mexico. Populations extend northward in the Mississippi Valley to Illinois, Indiana, and southwestern Michigan. Geographic isolates occur in northern Indiana, southwest Michigan, northeastern North Carolina, and southeastern Virginia.(Petranka 1998) This range is occupied by three subspecies, they are S. i. intermedia, S. i. nettingi, and S. i. texana. All of these subspecies only vary slightly in physical characteristics such as length and color (Conant and Collins, 1998).
- Aquatic Biomes
- lakes and ponds
is an eel-like salamander with a long slender body (18-68 cm long) and a very small dorsal fin that runs from the vent to the tail tip. It has only a pair of front legs; each foot has four toes. The front legs are very reduced and the rear legs are completely absent. The head is rather flattened, and there are bushy external gills located on each side of the head. varies in coloration from light grayish green to olive or black; there are also small irregular markings (dots) that are visible on lighter colored individuals.
- Development - Life Cycle
- Key Reproductive Features
- gonochoric/gonochoristic/dioecious (sexes separate)
- Average lifespan
- 6.3 years
- Max Planck Institute for Demographic Research
- Average lifespan
is a nocturnal species, which may minimize predation risks from 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, will burrow into the mud were it can survive for months. In this situation 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.
is 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).
feeds primarily on aquatic invertebrates such as crustaceans, insect larvae, worms, and snails. They will also readily consume young amphibian larvae and their own eggs. often feeds by gulping large quantities of material at a time, which is filtered through the bronchial openings. Vegetable matter sometimes found in their digestive tracts is probably eaten accidentally.
- Animal Foods
- terrestrial non-insect arthropods
- terrestrial worms
- aquatic crustaceans
Economic Importance for Humans: Positive
Sirens are occasionally used for fish bait, but this species normally attracts little attention from humans. They occupy a predatory niche in shallow freshwater habitats, and have ecological value in the environment.
Economic Importance for Humans: Negative
On occasion a Siren might take a fisherman's baited hook, but this would be an uncommon and minor annoyance. These animals are properly considered harmless to human interests.
is extremely rare and possibly extirpated in Michigan but this species is not threatened over most of its range. It could be harmed by chemicals such as Rotenone, which is used as a fisheries management tool and can be fatal to aquatic amphibians such as . Another factor that may affect the vitality 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.
- bilateral symmetry
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. Synapomorphy of the Bilateria.
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 use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
mainly lives in water that is not salty.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
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
- native range
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.