In 2007, the St. Louis Zoo’s WildCare Institute announced that their staff herpetologists, including herpetoculturists, and colleagues had achieved the first-ever laying of Ozark hellbender salamander eggs in captivity using only environmental cycling. Although the eggs were not fertile, this was a monumental achievement for hellbender propagation and conservation.
Last month, after a decade of collaboration, the Ron Goellner Hellbender Conservation Center at the Zoo’s Herpetarium and the Missouri Department of Conservation (MDC) officially established a successful breeding program for hellbenders with the hatching of Ozark hellbenders. Neither the federally endangered Ozark hellbender or the more common subspecies– the Eastern hellbender–have ever been bred in captivity. Missouri, incidentally, is the only state where both subspecies of hellbenders occur.
My first encounter with an “Allegheny Alligator” was in front of a glass terrarium at the Cleveland Museum of Natural History. I had signed up for a graduate class in herpetology taught by the museum’s Curator of Vertebrate Zoology, Dr. Tim Matson– a salamander aficionado and expert. So it did not come as a surprise that like other scholastic teaching venues in the organismal sciences his had a living, wet animal ambassador hanging around.
The accepted common name for our classroom’s resident giant salamander is hellbender. In the vernacular you will find colloquial names like “snot otter”, “devil dog”, and “grampus”–all fairly pejorative names. At first glance they do look rather fierce and perhaps unsightly, but they are actually quite docile aquatic amphibians. Since writing about their close relatives, the larger Japanese giant salamanders and visiting them on exhibit here in the states, I have come to think of the cryptobranchids as beautiful animals.
A little bit of folklore and my own imagination lead me to believe that this bizarre amphibian species was a formidable foe. Having sustained bites from small, lungless plethodontid salamanders to bites from juvenile crocodillians, I was a bit wary of this unfamiliar herpetile where as my classmates questioned if it was actually alive. These solitary salamanders don’t move a whole heck of a lot once they get comfortable.
Hellbenders can bite if provoked, but it is fairly rare. These salamanders, the smallest of giant salamanders, attain lengths of over two feet and have lived as long as 29 years in captivity. With skin that is brown with black splotches, the Ozark hellbender has a slippery, flattened body that moves easily through water and can squeeze under rocks on the bottom of streams.
Since 1981, hellbenders were listed as extinct or endangered in four states and remain threatened throughout the rest of their range. Endemic to the U.S., there are two subspecies as mentioned: the Eastern hellbender and the Ozark subspecies.
The Ozark hellbender (Cryptobranchus alleganiensis bishopi) occurs in riverine habitats of southern Missouri and northeastern Arkansas and specifically in two river systems. They require cold, clean water to survive. “Capillaries near the surface of the hellbender’s skin absorb oxygen directly from the water–as well as hormones, heavy metals and pesticides,” said Jeff Ettling, Saint Louis Zoo curator of herpetology and aquatics. “If there is something in the water that is causing the hellbender population to decline, it can also be affecting the citizens who call the area home.” To ecologists they are barometers of ecosystem health–likened to “canaries in a coal mine”.
Over the past three decades populations of both salamander subspecies have succumbed to anthropogenic stressors aside from just habitat degradation (i.e. stream impoundments, pollution and siltation) and habitat loss; they have also been impacted by collectors seeking specimens for the pet trade.
There are only about 590 Ozark hellbenders in the wild. At one time there were 8,000 of these highly aquatic caudates living in the Southcentral Missouri waterways. The Ozark subspecies has seen a precipitous decline–a 70% decline–in the last decade. Due to these drastic declines, captive propagation became a priority in the long-term recovery of the species. Fortunately, the St. Louis Zoo and the Missouri Department of Conservation were already trying to conserve this vanishing species through sorta situ conservation efforts.
“We have a 15- to 20-year window to reverse this decline,” said Missouri Department of Conservation Herpetologist Jeff Briggler. “We don’t want the animal disappearing on our watch.”
In 2004, funding from private donors, the Missouri Department of Conservation, the United States Fish & Wildlife Service and the Zoo covered the cost of building sophisticated facilities including climate-controlled streams to breed the hellbender.
The hellbender propagation facilities include two outdoor streams that are 40 feet long and six feet deep. The area is landscaped with natural gravel, large rocks for hiding and artificial nest boxes, where the fertilized eggs were discovered. A nearby building houses state-of-the-art life support equipment used to filter the water and maintain the streams at the proper temperature.
In addition, two large climate-controlled rooms in the basement of the Zoo’s Charles H. Hoessle Herpetarium are the headquarters for the program. The facilities recreate hellbender habitat with closely monitored temperatures, pumps to move purified water, sprinklers synced to mimic the exact precipitation and lights that flick on or dim to account for brightness and shade. The largest room includes a 32-foot simulated stream, complete with native gravel and large rocks for hiding. It houses a breeding group of adult Ozark hellbenders from the the White River in Missouri. Once the hellbender offspring reach 3 to 8 years of age they will be released back into the wild.
Please read my post on Japanese giant salamanders for more information on the biology and conservation of Cryptobranchidae in captivity.