Q: While fishing the docks near John's Pass in Madeira Beach, Florida, I caught a black drum that weighed about 3 or 4 pounds. It put up a good fight, but interestingly did so without a tail fin. Apparently the drum's tail had been cut or bitten off, perhaps as a juvenile, because the wound had healed perfectly. The fish seemed extremely healthy, and I was amazed that it could fend for itself so well. I released the drum, but wondered how long it would be able to survive.
St. Petersburg, Florida
A: Since its wound had already healed and the fish appeared healthy, it could live to a ripe old age - for black drum. Many fishes swim nearly as well without their caudal fins as they do with them, although they may lose some speed and maneuverability. If you looked at a drum (or many other fishes, for that matter) from above as the fish swam, you'd see that its body doesn't remain rigid. Rather, muscles bend its body to produce a series of posterior-moving waves, or undulations, along a portion of its length. These cause the body's surface to push backward against the water, which in turn propels the fish forward. A friend of mine has a panther grouper (Cromileptes altivelis) that lost its entire caudal fin when it was very young. He has kept the fish in a marine aquarium for several years, and it has no problem competing for food with larger, more aggressive fishes or maneuvering around the various rocks and corals in its tank. - Ray Waldner