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Description: Greater sirens are large, eel-like, salamanders
with two forelimbs, external gills and a flattened tail. Although
they can approach a full meter in length, most adults are 50-70
cm total length. They vary in coloration throughout their range
but are generally an olive green or grayish color with yellow
or green flecking along their sides and dorsum. Smaller greater
sirens can be differentiated from sympatric lesser sirens by counting
the number of costal grooves between the armpit and anus. Greater
sirens typically have 36-40 costal grooves while lesser sirens
have 31-35 costal grooves. Amphiuma, while superficially
similar in appearance, have a round tail, lack external gills
and have four reduced "limbs" that are much less developed
than the forelimbs of Siren.
Range and Habitat: Greater siren are found along the Atlantic
and Gulf Coastal Plains from Virginia south through Florida and
west to parts of eastern Alabama. Disjunct populations may exist
in parts of Southern Texas and Mexico along the Rio Grande river
valley but further genetic investigation is required to determine
their identity. The greater siren uses a wide variety of wetlands
but is found most often in slow or still bodies of water that
are heavily vegetated with a thick layer of organic muck or mud.
Because of their ability to aestivate for years at a time (one
lab specimen aestivated for 5.2 years), greater siren can thrive
in seasonal wetlands.
Habits: Breeding activity has been observed in February
and March and fertilization is presumed to be external, however
the exact mechanism of breeding has yet to be documented. Greater
siren occasionally give off a "yelping" sound when handled
that is likened to the distant call of green treefrogs (Hyla
cinerea) or young ducks. Clicking sounds have also been reported
for Siren lacertina. They feed on many different invertebrates
and occasional aquatic vertebrates with a possible preference
for snails and other mollusks in some areas. Captives can live
up to 25 years but no longevity information for wild animals is
available.
Conservation status: The greater siren is considered common
but is patchily distributed along the periphery of its range.
There is not much data available for the population status of
Siren lacertina across its entire range.
Pertinent references:
Hanlin, H. G., and R. H. Mount. 1978. Reproduction and activity
of the greater siren, Siren lacertina (Amphibia: Sirenidae),
in Alabama. Journal of the Alabama Academy of Science 49:31-39.
Petranka, J. W. 1998. Salamanders of the United States and Canada.
Smithsonian Institution Press. Washington, DC.
Sorensen, K. 2004. Population characteristics of Siren lacertina
and Amphiuma means in North Florida. Southeastern Naturalist
3:249-258.
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