"He must, so know the starfish and the student biologist who sits at the feet of living things, proliferate in all
directions. Having certain tendencies, he must move along their lines to the limit of their potentialities."

John Steinbeck - Log from the Sea of Cortez

Friday, May 21, 2010

Fish o' the Day - Southern stingray

It's proving difficult to get back into a routine. Lots of news items sitting here on my desk, but still feeling residual laziness. Not gonna worry about it too much - summer semester will be here soon enough. For now, the return of FOD.

Spent quite a bit of time wade-fishing Santa Rosa Sound last week, and saw plenty of stingrays. They're almost like alligators in the Everglades - very impressive to see such a high density of a large predator. Dasyatis americana is widely distributed through the tropical and temperate Atlantic and in the Gulf and the Caribbean. They can be big, reaching a "wingspan" of as much as 6 feet. A really big one may push 200 pounds in weight. Their claim to fame, of course, is the "sting" or barb, which is a modified denticle found about a third of the way down the long, whip-like tail. Grooves on the barb carry a proteinaceous poison which can certainly cause some problems for someone unfortunate enough to be "stung." It's rare, however, as stingrays will usually do whatever they can to avoid a confrontation. The most dangerous situation occurs when a wader or snorkeler steps on or swims over a partially buried stingray in shallow water. The toxin can be partially denatured by hot water, and this is a fairly effective first aid prior to a visit to the doctor.

Southern stingrays feed primarily on crabs and mollusks, although they'll take an occasional small fish if they can get one. They're ovoviviparous, meaning that they give birth to live young. After the smaller male impregnates the female, the eggs hatch out internally. The female then gives birth to five or so young rays.

On Monday, I kept an eye on a good-sized ray, perhaps three feet across, that shared with me the sandy edge of a Santa Rosa Sound seagrass bed in about two feet of water. I assume she was keeping an eye on me as well, and eventually she took flight into the deeper waters of the Sound.

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