Natural History of Sirenidae lacertina

Natural history- Sirenidae lacertina

            Sirenidae lacertina commonly known as the greater siren, range from 20-30 in (51-76 cm) with a record length of 38.5 in (97.8 cm). They have 2 small forelegs that are easily hidden by their large external gills that are in close proximity. They are olive in color to light gray; the back typically darker than the sides. Young become a darker color as they near maturity. (Field guide) There are no Sex dimorphisms, so it is difficult to determine the gender of the greater siren that was encountered on the field trip, which is pictured below.

            Breeding activity is observed in February and March, (this specimen was found Feb 26).  They are reproductively mature at 2 yrs of age, and have a captive lifespan of around 25 years. Though still not known for certain it is inferred that fertilization is external. Females will guard their eggs in the shallows until they hatch and then return to deeper water with no further parental care (ADW). When handled, they occasionally will produce a sound that resembles the call of the green tree frog (amphiaweb).

            Greater Siren are carnivorous and feed on small bugs such as insects or spiders, small fish and other aquatic organisms such as crustaceans, gastropods, bivalves, crayfish and mollusks. Alligators and mud snakes prey on greater siren and in response the siren are able to produce sounds to intimidate the predators such as the green tree frog-like call, and other hissing noises. In addition, muscular tails help to get away and they can bite as last resort. (ADW)

            Greater sirens lack a terrestrial life as their external gills might suggest, and therefore are found only in freshwater aquatic environments throughout their entire life span.  The freshwater regions that include the greater siren are temperate; the overall habitats range from as far north as Virginia and as far south as Florida and as far east as eastern Alabama. (amphiaweb)

            This find was extremely exciting, being one from my very first field experience ever; it was just about all I could talk about for a while. I was so impressed with it and the experience overall that I would even pull up the herp class pictures almost every time I brought it up to anyone... I was so proud. It was a great and exciting new experience, and being a huge fan on half-human/ half-critter mythological creatures (such as the satyr, the centaur, and the (mermaid-like) siren), I enjoyed further excitement from the finding of this epic two-legged amphibian, as it resembled my favorite of these half-human creatures. This specimen was absolutely gorgeous; I adored its sleek coloration of its eel-like body and the majestic external gills that floated just over the gentle forelimbs.

Sources:

Peterson Field Guides: Reptiles and Amphibians (Eastern/ Central North America)

http://animaldiversity.ummz.umich.edu/accounts/Siren_lacertina/

http://amphibiaweb.org/cgi/amphib_query?where-genus=Siren&where-species=lacertina

http://srelherp.uga.edu/salamanders/sirlac.htm