Salamanders: hidden amphibians with conspicuous secrets
By Austen Verrilli, CG Science
Author’s note: My source asked me not to disclose the location to which we traveled to protect the salamanders from too much human invasion. Patience and thorough searching will net many.
The hills lay hazy with a light fog. A drizzle of rain falls from the sky. Cool air rolls along.
“Perfect salamander weather,” says Mike Haughey, an Ohio University graduate student studying morphology.
Salamanders are mysterious and elusive creatures. The small amphibians coast swiftly along stream beds and live beneath rocks, leaves and rotting logs. Some reside underground, but most live near a water source. They feed on worms, bugs, other salamanders and other creatures beneath and above the water.
Today’s mission is simple: find and catch the sly amphibians. Haughey’s goal is to study the regional genetic trails of the spring salamander (Gyrinophilus porphyriticus). Spring salamanders reside in southern and eastern Ohio. Specifically, Haughey wants DNA samples to compare to other spring salamanders from around Ohio.
The secondary streams that we search are small trickles that roll through ravines. Flat rocks occupy much of the stream beds and trees fall and rot in the flow of the water. Nothing seems to be alive besides a few mosquitoes. When we flip a rock over, things change. Partially exposed worms wiggle genteelly. Beatles scurry under other rocks and brush. Occasionally a crawfish scuttles away in a fighting stance. The salamanders reside beneath only the most choice rocks and rotten logs.
Salamanders and amphibians are valuable to their ecosystems because they act like living habitat health sensors. Kipp Brown, a marine biologist at the Ohio Department of Natural Resources, described amphibians as indicator species. An indicator species displays the health of its ecosystem. The indicator species gauges habitat through the health of the species population.
“Amphibians show us things (in a habitat) have to be just right,” Brown explained.
A large amphibian population in an area means that the ecosystem is probably healthy. A lack of amphibians may mean the environment is too deficient to sustain larger life.
The streams we climb are healthy. The water is clear except when we disturb it. Eventually a rock reveals a small black salamander with a red stripe on its back (Plethodon cinereus). Red-backed salamanders are a commonly seen terrestrial salamander in Ohio. The salamander we see pauses to assess the situation then wiggles away from its potential assailants. One needs quick hands and little hesitation to catch the creatures.
Salamanders fail to adapt well to drastic changes in their environment. Brown said that excess silt in streams is one of the greatest detriments to stream habitats. The silt fills in crevices in rocks and makes the water cloudy. Silt also depletes oxygen concentrations in bodies of water. Compounds in the silt combine with oxygen and the water and react, using up oxygen sources.
Silt results from logging, development, mining and farming techniques which remove plants with deep roots from areas around streams. Once roots are gone, the soil begins to erode into streams and other bodies of water.
Brown said silt may be what caused the placement of the hellbender salamander (Cryptobranchus alleganiensis) on the endangered species list.
The salamander requires a large, clear water source to live in as it can grow up to 24 inches long, according to the book “Salamanders of Ohio.” Larvae take around three years to develop into sexually mature adults. But silt fills in hiding places larvae depend on to hide from predators, like their parents.
This hampers the survival of the species.
Salamanders show up often once the search gets going. A keen eye and patience reveals various salamander types, such as the northern dusky (Desmognathus fuscus), northern two-lined (Eurycea bislineata) and red-backed (P. cinereus) salamanders. But there is no sign of the spring salamander (G. porphyriticus).
Salamanders are very sensitive to water quality and require good oxygen sources under water. They have several different adaptations for respiration. Some retain their gills from metamorphosis for their entire lives while others develop lungs. The majority of salamanders can breathe through their skin in and out of water, called cutaneous respiration. Oxygen diffuses through the skin directly into the salamanders’ blood stream.
Haughey also said that acidic water is a detriment to salamanders living in and around streams. Iron disulfide, commonly called “fool’s gold,” is the main culprit for acidic water in Ohio. The material is a byproduct of coal mining.
Some streams run through old coal mines and the iron disulfide inside chemically reacts with the water. Oxidation occurs and lowers the pH of the water, netting a chemical makeup similar to sulfuric acid. Acidic water kills off most wildlife in streams partially because it depletes oxygen from the streams. The mine drainage is only treatable by adding basic chemicals to give the stream a neutral pH. These chemical systems are expensive and need to be routinely refilled to keep the water less acidic.
This spring salamander starts to sound mythical as we finish the second stream empty handed. Haughey says that the salamanders are subterranean. This makes finding them difficult. The long drive to the park propels us up to the next stream. Determined not to leave empty handed, we continue, heads down, rock by rock.
Many animals prey on salamanders including snakes, birds, frogs, and bigger salamanders. Salamanders use defense mechanisms to survive predatory strikes. They can shed their tails if necessary during predator attacks. Many reptiles use the same tactic to escape predators. The tail grows back over time. Others secrete poisonous or noxious fluids from glands in their skin. The juvenile eastern newt (Notophthalmus viridescens) is the only species in Ohio that uses toxic poison secretion for survival, according to the book “Salamanders of Ohio.” The book also states that salamanders that resemble the newt, like the red-backed, use their likeness of the newt to their advantage in survival.
Haughey said that environments with poison secretors and their predators sometimes lead to “biological arms races.” The predator develops increased resistance to the poison while the poisonous amphibian becomes more and more volatile through evolution.
Most salamanders in Ohio mate in the last weeks of winter or the first weeks of spring during the first night rain. Salamanders “pile out of the ground and make a mad dash to vernal pools (to mate),” Brown said.
Haughey said that the salamanders travel in packs to breeding grounds on that first rainy night. The pack even crosses roadways near breeding grounds as they travel.
Salamanders, like other amphibians, metamorphose from a larval stage, with some exceptions. The larvae take varying amounts of time to develop into juveniles which then develop into adults.
Some terrestrial salamanders like the red-backed salamander metamorphose while still in their eggs according to the ODNR Division of Wildlife Amphibian Field Guide. The eggs hatch and tiny infant salamanders emerge into the world.
Some salamanders retain larval characteristics their whole lives. The spring salamander never loses its finger-like gills as it develops through life.
Haughey goes up ahead as we search our third stream for a spring salamander, rock by rock. Then he calls out, “I think I got one!”
He tightly cups his hands together until he can safely deposit the small, spotted, pink salamander into a container. The salamander floats majestically. Its gills sway along with the water like elongated buoys. Haughey smiles as he holds the salamander.
“I need your DNA, buddy,” he says softly.
Haughey slices a small sliver off the tail and puts it in a vial. We release the creature which swims away. The small pink amphibian is the only spring salamander we find all day.
We are soaked from rain, our feet are soggy, and the morning’s coffee wore off hours ago. Haughey calls it an average day in salamander searching as we walk back to the car. To me, it seems quite the opposite; success and discovery usually don’t define average.