WHAT DO WE KNOW ABOUT PIRATE PERCHES?
Jack Sparrow is certainly the most unusual pirate on the scene these days, but I recently encountered a different sort of pirate with its own intrigue. I caught two little fish in a flooded area of some nearby woods and recognized them as pirate perch. Knowing the name of a plant or animal is the first step in identifying it; knowing someone who can tell you about its lifestyle, its behavior and other interesting facts is the next step.
I caught the fish in a minnow trap, a small wire mesh cylinder with inward-pointing funnels at both ends. My grandson and I had placed some in a shallow woodland pool alongside a swampy area. We also caught other captivating creatures, including leopard frog tadpoles and some seldom-seen aquatic salamanders called sirens. We brought the fish home in a plastic sandwich bag filled with swamp water and I took them to a colleague who is an ichthyologist to confirm their identity and to find out more about their biology. Dean Fletcher, a research scientist at the University of Georgia's Savannah River Ecology Laboratory, probably knows more about pirate perches than any other living person, whether angler or fisheries biologist. The coauthor of a book on freshwater fishes, he has written one of the few modern scientific papers on pirate perches.
The pirate perch, a freshwater fish but not a true perch, is the only living species in its family. It is common and widely distributed along the Atlantic and Gulf coastal plains and up the Mississippi River Valley to the Great Lakes. But most people, even seasoned anglers, are not likely to see one. Adults are usually less than 4 inches long and are primarily nocturnal. In addition, not many people fish in small tributary streams, in weedy waters thick with root masses or in the floodplain swamps of larger rivers.
A bizarre biological trait of pirate perches involves the adult anatomy. As with other fishes, reproductive products (eggs and sperm) and body wastes are released through the vent, which is usually situated under the body near the tail. The vent is in this location in juvenile pirate perches. But as a pirate perch approaches adulthood, something strange happens. The opening gradually migrates along the underside of the fish until it is positioned under the throat, just behind the gills.
have speculated on the function of this odd placement of the vent since
it was first described in 1824. As the scientific paper by Dean Fletcher
and his colleagues says, "We solve[d] the conundrum through a combination
of intensive field investigations, underwater filming, and molecular parentage
analysis." In other words they studied the fish extensively in its
murky habitat, filmed its behavior and used DNA analyses to see who the
parents were of various offspring. Their discoveries were made in the
cool waters of late winter and early spring when pirate perch begin spawning.
and I released the two fish we had caught, still in good condition, back
into their wetland home. Let's hope they find the right root masses to
produce their young, leading to future generations of this unusual little
fish. And why are they called "pirate" perch? If you put one
in your home aquarium, it will apparently have no qualms about attacking
smaller fish--to eat them, of course, not to take their money and jewels.
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