An armored, Amazonian catfish. That eats wood from fallen logs – and, when desperate, the feces of its fellow catfish. With teeth shaped like spoons to make the eating easier. And oh, it’s a new species.
You gotta know more, right?
It’s all in a day’s work for Nature Conservancy freshwater scientist Paulo Petry, who with colleagues netted the first whole specimens of the species several weeks ago on a scientific expedition to the Fitzgarald arch, one of the remotest parts of the Peruvian Amazon — a region bursting with biodiversity, but also under threat from development.
I caught up with Dr. Petry to find out more about the fish, why the region is so special, and why discovering new species isn’t such a big deal…once you’ve done it a dozen times or so.
Let’s first talk about this fish — it’s not pretty, is it?
PAULO PETRY: Beauty is in the eye of the beholder. I have scientist friends who do work on the blobfish, and they think it’s beautiful!
How big are these specimens, and where did you find them?
PETRY: The largest one is about 65cm, the other two are half that size. They were caught at the confluence of the Purus and Curanja rivers. The Curanja is a tributary to the Purus River in Peru.
Why is it armored?
PETRY: There are 35 different families of catfish on Earth. Armored catfish are unique to South America. They’re the most diverse group of catfish in South America — probably close to 800 species. They’re a fairly evolved, and a very specialized group within catfish.
How unusual is it to find a fish that eats wood?
PETRY: There’s a very small group of catfish that do that. Some fish burrow into logs, but fishes that specialize in eating wood is a very small group. The ability to digest wood comes from a protozoan that lives in their intestinal tract. It’s able to convert the wood cellulose into a different kind of sugar that can be assimilated.
That’s one of the biggest issues when people bring these fish into the aquarium trade — they let them starve for very long times for shipping, the protozoan in their belly dies, and then they can’t digest wood. If you put another fish from the same group that is in good condition in the tank with them, the starving fish will eat the feces of the healthy fish to reinoculate itself with the protozoan, and then it will be able to eat wood and survive.
Yummy! Had local people known about this fish before, or was the discovery of the fish a true discovery for humanity and not just science?
PETRY: Local people eat it. In the area in which we found it, it’s largely indigenous communities in this large park. These are the Nahuan people. They have 5 different ethnicities; the one we work with is the Sharanahua (which means “the good people”). They call the fish Ishgunmahuan — which in their language basically means “large armored catfish.” In Spanish, it’s “carachama gigante.”