Salamanders have some fascinatingly unusual traits | ECOVIEWS

Q. Salamanders come in many colors and are widespread, yet they seem to be one of the least-appreciated groups of animals. Most of my friends have never even seen one. What interesting facts could I tell them about salamanders?

A. Your friends are not the only ones unfamiliar with this fascinating group of animals. Salamanders are more common in the eastern half of the country than people realize. A classic scientific study published nearly 50 years ago estimated that the total weight of woodland and stream salamanders in New Hampshire was twice that of birds. In other words, salamanders were a more significant part of New England biodiversity than birds — a highly visible group of animals with which everyone is very familiar.

A walker passing through a forest anywhere from Alabama to South Carolina to Virginia passes hundreds of salamanders they never see.

For some other facts about these intriguing animals, I asked Larry Wilson, a herpetologist and salamander expert at Emory University, for his top 10 notable facts.

Green salamanders, like this one from North Alabama, inhabit mountainous habitats from coast to coast but are seen by few people. [Photo courtesy Parker Gibbons]
Green salamanders, like this one from North Alabama, inhabit mountainous habitats from coast to coast but are seen by few people. [Photo courtesy Parker Gibbons]

• 1. All salamanders are carnivorous. Most eat insects and other invertebrates, but some, such as dusky, spring, and tiger salamanders will eat other salamanders, including smaller members of their own species.

• 2. Salamanders do not have vocal cords. Some species can make squeaks, clicks or snapping noises with their jaws or by letting out quick exhalations. They communicate mainly through touch and chemical signals.

• 3. Some permanently aquatic salamanders have a lateral line system on their head and sides like those of fish, permitting them to detect vibrations in the water and identify movement of prey and potential predators.

• 4. Some salamanders have lungs, some have gills, some have both lungs and gills. All can respire through their skin. Many of the woodland salamanders have no lungs or gills; they respire only through their skin.

• 5. Salamanders exhibit the best regenerative ability among all vertebrates. They can achieve scar-free healing and can replace significant parts of eyes, heart, brain, spinal cord, jaws and gills. They are also able to regenerate entire appendages throughout their lifetime.

• 6. Many salamanders, including hellbenders and marbled salamanders, will guard, care for and defend their eggs until they hatch.

• 7. Many salamanders begin their life as eggs and larvae in the water then spend their adult life on land, making them one of the best biological indicators of an ecosystem’s overall health.

• 8. Salamanders are ectotherms, which means they do not internally regulate their body temperature like birds and mammals. They are much more energy efficient, requiring only a fraction of the food of that of warm-blooded vertebrates.

• 9. No eastern salamanders are venomous (actively injecting poison into the body), but many produce toxic chemicals on their skin that make them dangerous if eaten or touched. Newts are salamanders that produce a powerful poison called tetrodotoxin, which can be fatal if ingested by a would-be predator.

• 10. A salamander can have up to 40 times the DNA of humans. Their cells are larger than those of most animals, which allows them to accommodate large amounts of DNA. Such information may be useful in future research in medical genetics.

If that list is not enough to impress your friends, here are a couple more facts.

The smallest salamanders in the world, less than an inch long, occur on isolated mountaintops in Mexico. The largest salamander in the world is 4 feet, 9 inches long and lives in Japan. A Chinese salamander can get even larger, but the biggest ones are believed to be gone because of habitat loss and human consumption.

Another fact that should be of interest to the medical profession is that decades-old salamanders show no signs of senescence, or deterioration because of age.

Clearly, salamanders are a group of animals we need to keep around. To do so will mean keeping our natural habitats intact and unpolluted. Salamanders will be the first to let us know when we have a problem.

Whit Gibbons
Whit Gibbons

Whit Gibbons is professor of zoology and senior biologist at the University of Georgia’s Savannah River Ecology Laboratory. If you have an environmental question or comment, email ecoviews@gmail.com.

This article originally appeared on The Tuscaloosa News: Salamanders have some fascinatingly unusual traits