Once upon a research grant, scientists strapped three dead alligators into weighted harnesses and deposited the corpses 6,600 feet (2 kilometers) down in the Gulf of Mexico.
The first gator was overrun with giant pink crustaceans within a day and slowly eaten from the inside out.
The second gator was devoured down to its skull and spine after 51 days.
And the third gator? Well, nobody knows; its corpse was ripped from the harness and carried off by an unseen predator within a week, leaving behind some torn rope and unsettled sand.
This is either the least-satisfying fairytale ever, or the results of a strange new marine-food-cycle study described in the journal PLOS ONE. (Answer: It's both.)
The authors of the study (published Dec. 20) set out to test how carbon-hungry creatures of the deep, dark ocean would react to a food source they'd never seen before — namely, the scaly carcass of a freshwater gator (Alligator mississippiensis).
Denizens of the deep ocean can't afford to be picky eaters; it's too dark and cold down there for plants to undergo photosynthesis, and nutrients are scarce.
"The deep ocean is a food desert, sprinkled with food oases," study co-author Clifton Nunnally, of the Louisiana Universities Marine Consortium, said in a video about the experiment, released last April. "Some of these oases are vents in the ocean floor where chemicals come out or food falling from the ocean's surface."
Research into these "food falls" has mostly focused on large mammals, like whales, whose corpses provide a blubbery banquet for sea creatures large and small. While freshwater gator corpses can be cast into the ocean by hurricanes and other adverse weather, the ecological aftermath of such a "gator fall" has never been observed before now. Could the worms, crustaceans and other residents of the ocean floor find a way to penetrate the gators' thick hides and liberate the tasty meat within? The researchers didn't think it likely — however, they were quickly proven wrong.
When the team sent a camera-wielding robot to check on the first gator one day after laying it to rest at the bottom of the Gulf, they found the corpse being picked apart by huge, pill-bug-like isopods (Bathynomus giganteus) — some of which had already burrowed inside the gator and begun eating it from the inside. These crustaceans, the researchers noted, can store the energy from a single meal for months or years at a time, meaning that the hungry buggies scavenging the dead gator wouldn't have to work for more food for quite some time.
The second gator fared even worse. When the researchers revisited the corpse 51 days after deployment, it was picked clean, down to the bones. Those bones were caked in a mysterious brown fuzz, which a DNA analysis revealed to be a newly discovered species of bone-eating worm (genus: Osedax). This is the first time any Osedax species has been detected in the Gulf of Mexico, the researchers noted.
The final gator corpse disappeared from its harness before the researchers could spot any marine creatures eating it, but it's clear that the gator didn't wake up and swim away on its own. Considering that the creature and the harness weighed a combined 80 pounds (36 kilograms), it would have taken a large predator to chomp through the rope and haul the carcass away. A shark is the likeliest culprit, the researchers hypothesized.
So, to conclude the tale of “The Gators Who Fell Into the Sea,” many a bottom-feeding marine creature slaked its appetite on the tasty reptilian flesh — including some brown, bone-eating worms that nobody knew existed. And they all lived happily ever after, until their corpses were devoured in kind. The End.
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Originally published on Live Science.(opens in new tab)