Fish o' the Day - Gulf sturgeon

Watched an episode of "River Monsters" this afternoon that I had DVR'd while I was at the coast. Jeremy, breathless as always, was tracking down a lake monster in Alaska. After eliminating other possibilities, he decided to travel to the Columbia River to catch a white sturgeon to prove the identify of the Alaskan beast. OK, Jeremy's an entertainer, not a scientist. Still, his mention of the jumping Gulf sturgeon suggested tonight's FOD. Gulf sturgeon, Acipenser oxyrhynchus desotoi, are appearing in increasing numbers as they migrate up Gulf Coast rivers. It's become enough of an issue that the Florida Fish and Wildlife Conservation Commission recently issued an advisory suggesting that boaters slow down on the Suwannee River to avoid collisions with airborne sturgeon.

The Gulf sturgeon was recognized as a subspecies about 50 years ago. It's virtually indistinguishable from the Atlantic sturgeon (A. oxyrhynchus oxyrhynchus) - apparently you have to dissect them and measure the spleen. Gulf sturgeon are listed as threatened, with critical habitat including Florida's Suwannee, Apalachicola, Choctawhatchee, and Escambia Rivers, as well as the Pascagoula and Pearl Rivers in Mississippi. They're big fish, reaching 8 feet and 200 pounds. Gulf sturgeon are anadramous, spending part of the year coastal marine habitats and returning to rivers in spawning migrations. While in the Gulf, sturgeon apparently remain over seagrass beds or shallow muddy bottoms near shore. In the spring, they move upriver, spawning near the headwaters, and then spend the summer months in deep river water or near spring mouths. rs, returning to estuarine or gulf waters during the coolest months of the year. Sub-adult fish also participate in this migration. During the warm summer months, gulf sturgeon congregate in the deeper sandy and rocky bottom areas of rivers as well as near the mouths of springs. Interestingly, they seem to do most, if not all, of their feeding during the winter months when they are in coastal habitats. There, they feed on a variety of benthic animals including mollusks, crustaceans, and worms.

The reasons for jumping are unclear, although it's speculated that it may allow individuals to maintain contact with another. It's also been suggested that it may allow them to rid themselves of ectoparasites.

A brief video of a jumping Suwannee sturgeon....