Friday, January 30, 2009

Rio Grande Blue Catfish

Gliding through the greasy waters of the Rio Grande above the mud bottom on the deep outside reach of a bend, where the current ripples the surface on a moonless night, a giant blue catfish moves in on its prey.

Native to much of North America and existing as far south as Guatemala, the Blue Cat prefers large river systems like the Rio Grande. And unlike most of the other 40 fish species found in the Texas reach of this river, the blue cat is far from minnow size. The state record for a blue cat is 121 lbs caught on a rod and reel in 2004.

Like its predatory colleague, the gar fish, the blue cat along with its cousins the channel and the flathead have survived drought, pollution and artificial impoundments in the river that divert flow. The American Eel and the Atlantic Sturgeon that once roamed the nation’s fourth largest river system are no longer here.

The Rio Grande version of the blue cat is unique in that its slate blue body with the forked tail and multi-rayed anal fin is covered with dark spots found nowhere else. Some scientists speculate the spots are a camouflage mechanism that evolved for better survival.

For the most part, the blue cats eat other fish, like the Rio Grande Perch, or minnows, as well as frogs, mussels and insects and they will not hesitate to suck down the melting flesh of anything dead. Barbels, the cat-like whiskers near the mouth are chemo-sensory organs that allow the catfish to taste its environment.

Because Catfish have no scales, they are sun sensitive and can easily sun burn, preferring dark and deep water. Their smooth skin makes them efficient swimmers but they lack the body armor of a scaled fish.

Over 100 species of catfish swim the inland and coastal waters of every continent in the world except Antarctica and half of those species are found in America.

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