Sunday, March 11, 2018

Natural History: South Carolina slimy salamander


            Our trip to Caw Caw Interpretive Center last week was a bit too gray and rainy for spotting reptiles, but it turned out to be the perfect weather for catching plenty of amphibians!  The first Herp Alert of the day came when we turned over an old log to find this salamander hiding in the leaf mold underneath.  The salamander was about five inches long, with shiny black skin and mottled gray markings along its sides.  As soon as I picked it up, it began to secrete much more than any of the other amphibians we had handled (except maybe the amphiuma!).  I had scooped the salamander up along with a handful of leaves and dirt, and its defense mechanism managed to glue all the debris firmly onto my hands.  Dr. Welch told us the goo was a hint about its species, and sure enough, we were able to identify it as Plethodon variolatus, the South Carolina slimy salamander.


            Slimy salamanders are part of a large group, the Plethodon glutinosus species complex, which includes populations all across the southeast and mid-Atlantic regions of the US.  They belong to the Plethodontidae, the most diverse family of salamanders.  Salamanders in the Plethodontidae have no lungs and rely on the gas exchange they perform through their skin.  Many of them, including the slimy salamanders, have no larval stage and develop their terrestrial morphology in the egg instead.  Because of this, juveniles look like miniature versions of the adults in everything but their body proportions.  Based on its size, though, our salamander was most likely an adult.  Slimy salamanders do not need to reproduce in water, thanks to their direct development, so they instead lay their eggs in a damp, sheltered environment like the log where we found the adult.  Because salamanders tend to keep to a small home range, we released it back under the same log to continue enjoying the rainy day.


References:
Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America
Herpetology Program, Savannah River Ecology Laboratory, University of Georgia

2 comments:

Anonymous said...

I thought the slimy salamander was a really interesting amphibian to find. It is fascinating that one can identify this species by the feel of it, slimy! Thank you for sharing more about its life history and a few cool pictures. It's always exciting catching salamanders.

Allison Welch said...

How did we narrow it down to this particular species within the P. glutinosis complex?