Florida’s clown knifefish eye-popping and intriguing

scocking@MiamiHerald.comMay 1, 2013 

Captain Butch Moser holds up a clown knifefish caught beneath a bridge in a Palm Beach County canal.

SUSAN COCKING

Of the 23 established species of exotic freshwater fish in Florida, the clown knifefish has to be one of the most intriguing. With a flat silvery body and black spots ringed with white, the creature is eye-popping and sporty. Like a tarpon from a distant universe, it jumps high out of the water when hooked and uses its long, undulating anal fin to swim backward when you try to net it.

Boynton Beach freshwater fishing guide captain Butch Moser, 66, started catching the Asian invaders for his clients in the Ida-Osborne chain of lakes in Palm Beach County not long after the first one was spotted during 1994, probably a discarded pet from someone’s home aquarium. Numbers of clown knifefish grew steadily over the next decade and a half, but their range never really expanded north of West Palm Beach or south of Boca Raton. They kept Moser and his customers busy for hours at a time, targeting them around grassy shorelines and beneath bridges.

During December 2008, Nick Fusco caught a 13 1/2-pounder near Lake Clarke Shores that reigns as the International Game Fish Association all-tackle world record for the species. A chill in January 2010 knocked the fish way back; clown knifefish, like other tropical exotics, can’t tolerate water temperatures below 54 degrees for very long. But the back-pedaling jumpers have rebounded to the point that Moser and a few other guides and anglers target them again. Moser said he is far from the 50-fish days he enjoyed pre-freeze, but his clients recently have caught up to a dozen in a day, along with largemouth bass and other native species.

Moser said clown knifefish bite year-round, but the springtime spawn and the heat of summer are prime times, fishing mainly in early morning and at dusk. To bump up the odds of client success, Moser embarks on the lake system before dawn and cast-nets hundreds of threadfin shad that he keeps in an aerated 35-gallon live well on his Carolina Skiff.

“With shad, you’re catching everything out here,” Moser said, including largemouth, peacock and sunshine (hybrid) bass. His dissections of clown knifefish have revealed only shad – no shiners, crayfish or tilapia – in their stomachs.

On a recent outing to the canal separating Boca Raton and Delray Beach, Moser and a client caught and released three “clown fish” to 6 pounds within about three hours. Drifting and slow-trolling live shad below Styrofoam bobbers around grass lines and bridge pilings, they also released about a dozen largemouth to 2 pounds.

The Florida Fish and Wildlife Conservation Commission asks anglers not to release clown knifefish back into the water in order to slow their spread. There is no bag or size limit on the species. But Moser can’t bring himself to kill them.

“They don’t seem to be hurting anything,” he said.

Biological administrator Kelly Gestring of the FWC’s nonnative fish lab in Boca Raton, confirms the spotted back-peddlers “do not seem to have a measurable impact on the native species.”

Gestring said that during 18 years of sampling freshwater fish in the Ida-Osborne chain, he has collected fewer than 100 clown knifefish and can not estimate their population size. He said he has counted good numbers of bass, bluegill, sunfish and others occupying the same waters as the clowns with no signs the exotics are outcompeting the natives for food or habitat.

“We would prefer they were not here, but we can’t do anything to eliminate them,” he said. “If people would catch and keep them, then it could maybe slow their spread to other waters. They’re unusual and attractive and fun to catch.”

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