Monday, March 19, 2012

The Slimy Salamander: A Natural History


Family: Plethodontidae
    Subfamily: Plethodontinae
         Scientific Name: Plethodon variolatus
         Common Name: South Carolina Slimy Salamander

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During a recent field trip to Caw Caw Interpretive Center in Charleston, South Carolina, we stumbled upon this slimy salamander hiding under some vegetation. The salamander's length appeared to be around the expected 4 3/4"-6 3/4" and we did not determine its' gender. This species is characterized by skin that is mainly black with many whitish spots or brassy flecks or both. This species typically has 16 costal grooves and has a long, slender body with a long tail. They have 4 digits on their forelimbs and 5 digits on their hind limbs.

A distinguishing characteristic of this family are their nasolabial grooves, which travel downwards from each nostril to their upper lip. These grooves aid in pheromone reception during mating season. 

 http://www.herpetology.us/field_trips/2009/cades_cove_gsmnp_blount_co_.html


This species gets its' 'slimy' name from the sticky, glue-like substance they secrete from their skin glands which adheres to your hands. 

Habitat: This species shows ecological diversity in habitat by being terrestrial, aquatic, arboreal, fossorial, and troglobitic. In humid climates, this species may be seen throughout the year but encountered more after rainfall. In hot climates, they are known to estivate to avoid dessication. We determined this specimen was a slimy salamander based on its' physical characteristics described in our field guide. We  identified our specimen to be the South Carolina species because of its' home range. 

Diet: Slimy salamanders feed mainly on invertebrates such as earthworms and insects such as beetles, ants, and bugs.

Life History: This species displays elaborate courtship rituals, internal fertilization via spermatophores, and lay their eggs in moist environments. They go through direct development within the egg. Males are distinguished from females by their mental gland (circular gland) under their chin.

http://www.flickr.com/photos/71701055@N00/4095701565/

Males use their mental gland to transfer their pheromones to a female during a courtship straddle walks. She then uses her nasolabial grooves to wick up his pheromones by placing them on his dorsum. This is an example of chemical and tactile signals used in salamander communication. 

After identifying this specimen and handling it for a while, we let it go close to where it was located.


2 comments:

Allison Welch said...

Neat salamander!

UndiscoveredAnomilies said...

I found a salamander in my dirt that looks almost identical to this, I can't figure out what he is. But he's also SIMILAR to the White spotted Night Lizard, who eats humans, deteriorating a slime that has acidic properties to melt the skin for consumption.