Notophthalmus viridescens (Eastern Newt)
Field Experience
& Observation: On our very first field trip to the Caw Caw Interpretive
Center in Ravenel, SC we found several Notophthalmus viridescens or the Eastern
Newt. Newts are their own salamander family and are distinguished from other
salamanders for their indistinct costal grooves and non-slimy rougher skin.
These Eastern Newts had been caught in the minnow traps that were placed in a
very wet and muddy area. These newts were a deep rep with the tell-tale large
red outlined black spots on their backs (we did not count to find all 21 spots)
and speckles of dark spots on their bellies. This red coloring is what distinguished
them from being adults since adults are yellowish to dark greenish brown. All
were in the eft stage, even though the minnow traps were found in the water.
These efts were pretty hefty at about 3 inches long, but despite our efforts it
was too hard to figure out their sexes (males have high tail fins, black
tubercles on their thighs/rear feet, and a swollen cloaca when breeding). With
both the friendly newts and no-see-ums, Caw Caw was a beautiful place to visit.
I really liked getting to find these newts because I have never seen them
before in their native habitat.
Habitat & Range: Newts
like ponds, small lakes, marshes, swamps, ditches, quiet areas of streams, and
other places with continuous unpolluted water. Most of these bodies of water
will have few fish (i.e. fewer predators) and lots of aquatic vegetation to
hide in. Adults are seen to swim, crawl along the bottom, and just rest in a
motionless state. Terrestrial efts will live in the moist woodland areas that
around their adult counterparts.
So which one did we find at Caw Caw? Based on the range map
it should have been the Central Newt that is normally found without red spots (or
their spots will be partly outlined in black) in swamplands, woodland swamps,
ditches and river bottoms. The Central Newt often skips the eft stage because
of harsher (hotter, drier) environmental conditions. However, the Red Spotted
and Central varieties are very similar and they can intergrade. I think that
the ones that we found at Caw Caw are Central variety because this is a
great habitat they were exhibiting the eft stage.
Sources:
Reptiles & Amphibians Eastern/Central Guidebookhttp://www.caudata.org/cc/species/Notophthalmus/N_viridescens.shtml
2 comments:
What we caught were actually adults, which would explain their aquatic habitat, brownish dorsal coloration, and the male secondary sexual characteristics that we were able to observe. We didn't sex all ~10 of the newts in the trap, but we checked some and found one female and several males. Perhaps a female found her way into the trap and the males then followed her scent into the trap.
Adults can't regrow gills. But through paedomorphosis, some can skip the eft stage and go directly from larva to adult while retaining their gills. An amazing life history, indeed!
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