© 2024 St. Louis Public Radio
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations

Saint Louis Zoo shares secrets of salamander love at hellbender symposium

The Saint Louis Zoo is sharing its expertise in matchmaking ... for salamanders.

It's part of the 7th Hellbender Symposium, which has drawn more than 100 participants from the Midwest, the Eastern U.S., Japan and China.

Purdue University wildlife scientist Rod Williams is on his fifth hellbender symposium.

His lab studies the genetics and ecology of Eastern hellbenders, a subspecies that’s endangered in many states including Indiana.

The flat, slimy appearance of adult hellbenders has earned them some unflattering nicknames like "snot otter" and "lasagna sides," but at 10 months old they're still pretty cute.
Credit Mark Wanner | St. Louis Zoo
The flat, slimy appearance of adult hellbenders has earned them some unflattering nicknames like "snot otter" and "lasagna sides," but at 10 months old this one is still pretty cute (imho).

He said the conference is a great way to foster collaboration among salamander researchers, environmental managers and policy-makers.

“It also facilitates innovation from a scientific standpoint,” Williams said. “We come here, we hear about scientific findings from the community of hellbender ecologists, and that really helps us go to the next level. So we know what we know today, we know where the gaps in our knowledge are. And that really helps us facilitate closing those gaps.”

The Saint Louis Zoo has been successfully breeding federally endangered Ozark hellbenders since 2011 — making the zoo the first institution to breed hellbenders in captivity.

The zoo's curator of herpetology Jeff Ettling said since then, the zoo has raised almost 6,000 of them. “The whole east basement of the herpetarium is now hellbender central,” Ettling said. “I mean we literally have three big rooms and one small nursery room, three full time keepers, one part time keeper, one seasonal keeper, and then anywhere between five and ten college interns at any given time, that all they do is take care of hellbenders.”

The zoo has already released 1,759 Ozark hellbenders into Missouri rivers and streams in an effort to stabilize the wild population. In 2010, there were fewer than 600 left in Missouri and Arkansas.

Two artificial streams are home to the zoo's breeding population of hellbenders. The males guard the eggs in nest boxes that mimic large, flat rocks in the gravel stream bed.
Credit Mark Wanner | Saint Louis Zoo
Two artificial streams are home to the zoo's breeding population of hellbenders. The males guard the eggs in nest boxes that mimic large, flat rocks in the gravel stream bed.

Its relative, the Eastern hellbender, isn’t doing much better. Ettling said the zoo hopes to breed them next. “We have three males already,” Ettling said. “We’re trying to bring females in this year. And we’re comfortable that the techniques that we’ve used with the Ozark hellbender will be equivalent with the Eastern hellbender. So, that’s kind of our new horizon for us.”

With the help of the Missouri Department of Conservation, the zoo is tracking the hellbenders it releases using two types of tags: coated wires for the smaller hellbenders, and PIT (passive integrated transponder) tags for the larger ones.

Ettling said a PIT tag provides each animal with a unique identifier, like a social security number. “We use it in most all of our animals here at the zoo, and it’s commonly used by veterinarians in dogs and cats.” PIT tags are also known as RFID chips.

Missouri Department of Conservation herpetologist Jeff Briggler said so far, hellbender survival has been good. But he said the real test will be if they can confirm the captive-raised salamanders are reproducing in the wild. “Then, after that, we’re hoping that the population will begin to increase,” Briggler said.

Even as adults, hellbenders can squeeze into tight places — like this PVC tube, or the rocks they like to hide under in natural streams.
Credit Mark Wanner | Saint Louis Zoo
Even as adults, hellbenders can squeeze into tight places — like this PVC tube, or the rocks they like to hide under in natural streams.

Scientists don’t know exactly why hellbenders have been dying off in the wild. One of the main causes is likely to be habitat loss and degradation — too much sediment washing into formerly clear-water streams. Another is a disease known as amphibian chytrid fungus, which has also caused huge die-offs of frogs.

U.S. Fish and Wildlife Service biologist Trisha Crabill said in addition, hellbenders are developing deformities. “A lot of the animals are either missing their toes, their whole feet, or in some instances their whole limbs,” Crabill said.

But the cause of those deformities remains a mystery. “Not all animals that test positive for chytrid fungus exhibit those abnormalities," Crabill explained. "And not all animals exhibiting the abnormalities test positive for amphibian chytrid fungus."

The Saint Louis Zoo’s Jeff Ettling hopes captive breeding can help restore hellbender populations. “We’ll probably be breeding animals here for at least the next 15 years,” Ettling said. “So, pretty much the rest of my career, we’ll be breeding hellbenders.”

Follow Véronique LaCapra on Twitter@KWMUScience