Last year, in a scientific first, researchers dropped alligators 2,000 meters (6,560 feet) onto the ocean floor to see what lurking deep-sea creatures would make of this unusual new snack. Now, they are back with a published study and juicy new details on what happened at these gator buffets.
Back in February 2019, researchers from the Louisiana Universities Marine Consortium (LUMCON) executed the very first experiment on reptile falls in the ocean. A “fall” is when an animal – usually something big and substantial, like a whale – dies and its carcass falls to the seabed, providing an incredible banquet for a range of deep-sea critters.
For marine scientists, a fall provides unparalleled insights into deep-sea ecosystems and food webs, seeing who turns up, when, and who eats what. The LUMCON team wanted to know how deep-dwelling creatures in the Gulf of Mexico would react to an uncommon food source – alligators more commonly found in freshwater environments. Though, not always.
“There is actually really good evidence that alligators make it out into the gulf offshore in major flooding events especially because we have two major river outlets here,” River Dixon, one of the study authors told IFLScience last April. “So, we had good evidence that there were alligators out there but we didn’t know what that meant for the deep sea.”
In the study published in PLOS One, the team posited that the tough hides of the three American alligators would potentially impede some scavengers unused to their dinner coming in such protective packaging. Not so, it turns out.
One alligator was overrun with giant pink isopods (Bathynomus giganteus), foot-long scavengers known to respond to food pretty quickly. Within 24 hours, they’d penetrated the hide, burrowed their way through the skin, and started eating their meal from the inside out.
The second was picked clean in just 51 days, completely devoid of all soft tissue and leaving behind just a spine and a skull. However, this provided the researchers with the first evidence of a brand new species of bone-eating worm – seen here as a reddish-brown fuzz. It appears to be a new member of the Osedax family, sometimes known as zombie worms, and will be named in due course. It’s the first time any Osedax has been seen in the Gulf of Mexico.
The third alligator suffered an unknown fate. The first observations of it taken eight days later revealed an empty rope. The 20-kilogram (44-pound) weight, shackle, and part of the line (all used to weigh the gator down) were found nearby. Evidently, it was snaffled by something that did not want to share its good fortune.
Calculating what could drag the combined weight of alligator carcass and items (about 36 kilograms/80 pounds) and has a bite strength that could snap clean through the rope places the suspicion on a large shark, most likely a Greenland or sixgill.
It turns out denizens of the deep can’t afford to be picky, food sources are scarce, and nothing is going to look a gift gator in the mouth.