CT Shows It's A Fish-Eat-Frog, Frog-Eat-Fish World Out There


Rachael Funnell

Digital Content Producer

clockNov 18 2020, 20:08 UTC
Can I offer you a slice of the forbidden Turducken in these trying times? Images by Maxwell Bernt courtest of the American Museum of Natural History

Can I offer you a slice of the forbidden Turducken in these trying times? Images by Maxwell Bernt courtest of the American Museum of Natural History

The lead up to Thanksgiving has revealed an aquatic alternative to the famed Turducken (turkey, duck, and chicken) worth a try for anyone looking to put on an aquatic spread. The recipe, captured using computerized tomography (CT) by Maxwell Bernt scanning samples at the American Museum of Natural History, revealed that one of the fish from the museum’s ichthyology collection had, in life, eaten a frog who, in life, had eaten a fish. What's more festive than a case of Inception indigestion?

The unusual Russian doll was revealed in the subsequent scans showing the skeleton of the frog in the throat of the fish, with the skeleton of a smaller fish inside the frog. The outer layer of the “Catfroginnow,” as dubbed by Gar celebrity Dr Solomon David, is a catfish (Clarias stappersii). Eating amphibians isn’t unusual for this species, but to capture a frog still with the remains of what Bernt suspects is a cypriniform judging by the looks of the pharyngeal jaw still in its gut is quite the catch.

This catfish got more than it bargained for when it scoffed down a frog. Maxwell Bernt at the American Museum of Natural History

Computerized tomography is a medical imaging technique that combines X-ray measurements taken from different angles. The result is tomographic images of a body, or fish, which can be layered and reviewed to provide a detailed account of what’s going on inside without ever having to cut into the sample. New imaging platforms now mean the images from CT scans can be quickly processed and labeled to show the complex and interlocking internal features for diagnostic purposes or as part of research.

Judging by the pharyngeal jaw, Bernt suspects the surprise fish inside the surprise frog was a cypriniform. Maxwell Bernt at the American Museum of Natural History

CT scans of fish are a common feature in ichthyological research, and historically people have stuffed everything from sharks to the deepest fish in the ocean inside scanners, and the unique view they provide often reveals surprises. Earlier this year, a scan of a wrasse revealed the unfortunate fish was hiding a grim secret, as in place of its tongue sat a parasitic isopod. These crustaceans crawl into the mouths of fish and eat their tongues to make room so they can sit at the opening and wait for its host to provide some snacks.

Fish gotta swim, frog gotta eat. Bigger fish also need to eat. Maxwell Bernt at the American Museum of Natural History

Indeed, it seems fish have been found to contain all manner of strange and disgusting contents. According to a post from the Angling Trust, everything from mobile phones and money to human remains including fingers, genitals, and the body of a Nazi have been found inside fish. I suppose, in that respect, CT scanning fish specimens is like a box of chocolates. You never know what you’re gonna’ get.