Sounds like a rock group, but hellbenders are mute, cryptic, and uglier than any band! I imagine some American pioneer naming them after turning over a rock in a mountain stream and recoiling in horror at the sight of something looking like it crawled out of H***. But hellbenders are among nature’s innocents (despite their jaws) and, like the Elephant Man, they should draw our sympathy because we, too, would want to hide under a rock if we had the ugliest mugs in the world.
A hellbender’s body extends two to three feet behind its slimy head, sprouting two pairs of stumpy legs before reaching the tail. They live in rivers like the Greenbrier and Cheat in West Virginia that drain pristine water from the mountains and harbor the diet of crayfish (“crawdads”). Hellbenders are giant salamanders, and the Appalachian mountain chain is the redoubt of more of their species than anywhere else in the world, over seventy in all, mostly small, dainty, and colorful.
I have never found a Big Sal under a rock, but Nick and Tim grab one on their excursion to West Virginia in this video. They are slippery characters that are best left alone like other protected species with dwindling numbers.
Hellbenders like a quiet life, but their home stretches can quickly change temper after a storm, turning a gentle stream into a raging torrent that tosses slimy torsos against rocks, crushing and tearing their flesh. And yet deep skin wounds almost never go septic in salamanders because they evolved ways of repairing traumas and consequently live for 30 to 50 years, longer than almost every other animal in the forest except some large birds.
A family of small peptides called defensins help to protect them against infection by latching on before bacteria, fungi and viruses snuck into cells. We, too, have defensins for boosting our innate immunity by drinking our mother’s milk during the most vulnerable weeks of our young lives.
There are related peptides encoded in our genome, but they are shams because their pseudogenes have premature stop codons that produce truncated peptides that don’t work for us throughout life. Perhaps they were useful long ago, but we now depend on cells in the immune system to guard against microbes, and for the past eighty years have counted on the penicillin family when needed. I say “past” because overuse of these drugs is creating microbial resistance that could turn us back to the pre-antibiotic era. If defensins help to preserve salamanders in a turbulent environment perhaps we can synthesize analogous molecules as backups for penicillin.
These four-legged aquatic animals with a long tail look too alien to inform medical science, but their body plan and tissue architecture are not so foreign to our own. There is one huge, enviable difference. They have an amazing ability to regenerate amputated limbs that we lost way back in evolution along with the services of some defensins. If we could mimic their biology millions of patients could throw away prosthetic hands, arms and legs, and repair damaged internal organs by drawing on the regenerative potency that rests unbidden inside our bodies.
When part of a salamander’s body is lost a blastema forms at the site of injury containing stem cells and other cells that lose their specialized character as they ready themselves for a reconstruction job. Careful anatomical studies have shown that when limbs are regrown they become perfect copies of the originals. This process fails in us because of an absence of blastemas and scar tissue getting in the way.
But we are getting accustomed to surprises in biology, and there are grounds for hoping that the plasticity of cells can be harnessed one day for regenerating our bodies. If you see a salamander squatting in a glass tank in a lab you may think it is a scientist’s pet or a grotesque throw-back to the Cretaceous Era, but perhaps you are looking at the future, at something that will help to improve human lives, and revise your judgment of the beasts from Hell.
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Lovely video by Nick and Tim!