While checking the minnow traps that I set in southern Illinois, I discovered this fish which I’ve never seen before.
Pirate Perch are found in clear warm streams, oxbows and marshes with low currents and tend to congregate where there is dense vegetation, woody debris, root masses and undercut banks.
They are small, usually 4 to 5 inches, dark brown and can have a purple sheen on their sides. They often have a dark tear drop shaped marking under the eye.
The Pirate Perch is the sole member of the family Aphredoderidae. What is noteworthy about it is the peculiar position of its anus, which is located near the anal fin when the fish is young but gradually moves forward, to the throat, as the fish matures.
The reason why the fish’s vent was located at the front of the body instead of the back was revealed by field observations. It turns out that females thrust their heads into tangled root masses to lay their eggs and the males quickly follow suit, putting their heads in the same spot in the tangled root mass to fertilize the eggs. No other North American fish does this.
Charles C. Abbott, a pioneer ichthyologist, is credited with giving this fish its common name, after observing that a specimen he kept in an aquarium ate only other fish.