06/12/11

Hellbenders – Unique Jurassic Survivors

The other day my husband asked if I wanted to go see hellbenders at a state park in Pennsylvania. I knew that hellbenders were salamanders, but I didn’t know much else about them. So I thought I’d learn something about them before we go in search of these unique creatures.

Eastern Hellbenders (Cryptobranchus allegoniensis), the only member of the giant salamander family found in North America, are large aquatic salamanders that can grow from 10 to 20 inches in length. They have wrinkled skin and their color varies from spotted yellowish to red and brown.

The Eastern Hellbender lives in fast-flowing, cold streams with rocky bottoms from southern New York to northern Georgia, but are most abundant in Pennsylvania, West Virginia, and Virginia. They are primarily nocturnal and spend most of their day hiding under logs or rocks. They like to eat snails and crayfish and are partial to worms, which sometimes leads to encounters with fishermen.

There are two common misconceptions surrounding this aquatic salamander—that it’s poisonous and that it spreads a slime on fishing lines that drives away fish. Both are untrue. The hellbender is harmless. But these misconceptions have led to nicknames such as devil dog and Allegheny alligator.*

Hellbenders have an interesting reproductive process. They mate late in the summer and the male then digs a shallow nest in the stream bottom beneath a log or rock. A female deposits 100 to 200 eggs in the nest as the male releases sperm to fertilize them. Dad then guards the nest for two to three months until the young hatch.

Hellbenders are considered a living fossil. They haven’t changed much since the Jurassic times, over 160 million years ago, which means they’ve been on Earth about 60 million years longer than humans. But human activity is causing them to decline dramatically in most areas.

Some causes for their decline include blocking of the animals’ migration routes, destruction of their aquatic habitat by dams and other development, as well as pollution, disease, and over harvesting for commercial and scientific purposes.

Here’s a National Geographic video about the hellbender. I wouldn’t try this at home (licking a salamander), but it does remind one that tasting really really bad is one of the defenses of animals like hellbenders.

Unike the hellbender in the video above, the hellbender in this video has been left undisturbed and despite its name, I think the hellbender is quite beautiful when you see it in its natural habitat:

*Most of the information in this post came from Longstreet Highroad Guide to the Pennsylvania Mountains by Greg and Karen Czarnecki.

02/9/10

Giant Salamander: Earth's Largest Amphibian

We confess to paying most of our attention in our posts on Frogs Are Green to the stars of the amphibian world—frogs—and not so much on other amphibians. So to make up for that, we’d like to introduce you to Earth’s largest amphibian—the giant salamander of China and Japan.

BB-Japanese-Giant-Salamander

This creature is considered a living fossil because it hasn’t changed much in 30 million years. To put things in perspective, 30 million years ago our ancestors were little primates hanging from trees. It would be millions of years before some of these primates descended from the trees, and millions of years after that before the first humans.

The giant salamander lives in mountain streams and lakes and can grow up to 6 feet long. It has four digits on its front legs and five digits on its back legs and is covered with a slimy protective mucous. It spends most of its time walking on the river bottom, though it can swim quickly. On land, its small legs won’t carry it and it must drag itself along.

Like many amphibians, the giant salamander is endangered due to habitat loss. Construction of dams converts  their free-flowing stream habitats into standing water or dries them up completely. They are also vulnerable to water pollution from mining activity and farming throughout their range.

Other threats to their habitat includes deforestation around the streams. This exacerbates soil erosion and causes increased runoff and siltation of the streams, reducing water quality and making it difficult for the salamanders to get enough oxygen through their skin. In addition, the giant salamander  is considered a delicacy and is also used in traditional Chinese medicine.*

On the BBC News site, Dr. Takeyoshi Tochimoto, director of the Hanzaki Institute near Hyogo in western Japan, gives a guided tour of this unusual creature.  (“Hanzaki” is the local name for the giant salamander.) After watching this video, however, I have decided not to hug a giant salamander if I ever meet one.  They have a very large mouth and several hundred small teeth on the top and bottom and can bite if angry, causing serious injury. Generally, however, this is a shy and secretive animal and is unfortunately relatively easy to catch.

*Information from BBC Wildlife Finder. Image above courtesy of National Geographic.