Wednesday, April 24, 2013

A dash of newt, spotted in red

The tranquil, forest buffered waters of one of several small lakes within Shawnee State Forest. This lake, and the others, plays host to scores of one of our most interesting salamanders. I visited this site last Sunday with John Howard and Mary Ann Barnett and we, quite naturally, spent some time working with these animals, and documenting them on our pixel-making machines.

A Red-spotted Newt, Notophthalmus viridescens, poses nicely on a log (with a little direction from the paparazzi). This animal is probably at least three years old, and could be much older than that. Newts operate in quite the opposite way of most salamanders, which are strictly aquatic when immature, and become landlubbers when adulthood is attained.

In their juvenile stage, which can last several years, Red-spotted Newts look very different than this, and are known as Red Efts. You can see photos and read about efts RIGHT HERE. When the brightly colored eft matures and transforms to an adult newt, it slips into the drink and becomes nearly as aquatic as a fish, as we shall see. On occasion, adult newts make short peregrinations from their pond during wet weather, as this one had done, but for the most part they remain in deep permanent water.

In addition to the red spots on the dorsal (upper) surface, newts are sparsely polka-dotted with black stippling below. In the looks department, these are probably not our flashiest salamander, but newts do have a certain charm to them.

An adult Red-spotted Newt is far more at home in the water than on land (or posed on logs). In this photo, we're peering through a foot or so of water to the bottom of the aforementioned pond. Three newts are visible floating in the water column, and there were far more than this. In just a short stroll along a small part of the shoreline, we must have seen 50 or so. Newts swim like fish, and the rudderlike laterally compressed tail - reminiscent of a muskrat tail - provides efficient propulsion.

Newts can operate with relative impunity in waters such as this, without fear of being preyed upon by voracious fish such as bass or bluegill. Their immunity stems from a toxic chemical defense system. Red-spotted Newts are infused with tetrodotoxin (TTX), which is the same stuff that would have you regretting (briefly) wolfing down a poisonous puffer fish. Apart from a suite of marine animals such as puffer fish, the only other group of animals known to carry TTX are amphibians. About 28 species in 10 genera - frogs, toads, salamanders - have been found to harbor TTX, and to date no antidote has been discovered to combat TTX poisoning. So, please avoid swallowing newts and their attendant neurotoxins. To do so would bring on severe muscular paralysis, and possible death, and neither of those things makes for a good field trip.

We discovered this pair of amorous newts entertwined in the shallows of the pond. It is breeding season for the newts, and the smaller male (presumably the male) has climbed atop the female and has her firmly in his grasp. The females apparently select their mate, and the chosen male will deposit a sperm packet (spermatophore) on the bottom of the pond. Mrs. Newt will then uptake the sperm via her cloaca, and later drop her fertilized eggs.

Newts don't become sexually mature until three years of age, and once adulthood is reached and they're in the breeding ponds, they can probably live a long life. It's possible that newts can live for ten or twenty years, maybe even longer.

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1 comment:

Buckeyeherper said...

One of my favorite lakes in all of Ohio...