Fish o' the Day - spot

Pretty unassuming name, right? My fish, spot. Actually, there was a time when spot was, in fact, MY fish. A significant portion of my dissertation work centered on Leiostomus xanthurus. So, welcome to another installment of Fish of my Life.

Spot are members of the Family Sciaenidae, the same family that includes the vastly more popular redfish and spotted seatrout. Spot are every bit as common, probably moreso, but they don't reach the sizes or provide the angling (or gustatory) experience supplied by their more celebrated cousins. Spot, which reach a length of 6 or 7 inches, are widely distributed in estuaries along the Atlantic and Gulf coast. They love to feed in soft sediments, where they move across the bottom, grazing like a herd of cattle. They're not feeding on marine plants, though. They're actually biting the bottom, taking mouthfuls of sediment which they manipulate in their buccopharyngeal apparatus (yeah, that's basically their mouths) to remove the small invertebrates that they rely on for food.

My Ph.D. work was completed in the lab of Dr. John Fleeger at LSU, a good man, a very good biologist, and a leading authority on the ecology of meiofauna, that unusual group of inverts that are too big to be "microscopic" and too small to be shrimp and crabs. Composed largely of nematodes and harpacticoid copepods, meiofauna are the primary food source for spot as they swarm into coastal estuaries. In one project, we investigated the manner in which spot could identify and utilize the patchy distributions that meiofauna are famous for. In fact, here's the paper. I spent the better part of a summer creating density treatments of meiofauna and video-taping feeding spot in laboratory aquaria. We found out that, indeed, they can localize their feeding in areas where holding greater concentrations of their tiny prey. Not only that, we discovered that the fish knew when they had slurped up a particularly rich patch of muddy substrate, manipulating it in their mouth like a relief pitcher with a fresh wad of chaw to remove all the good stuff. It's actually fairly sigificant in the way that it links the detrital and grazing food webs in estuarine systems.

Good ole days, but very tedious work. Still, an excellent model that I'm about to spring on some unsuspecting students of my own. Provided they're not reading this.