Tripletail
Tripletail is a fish found throughout the Gulf of Mexico and Caribbean. It also swims up the Gulf Stream and into the Atlantic, so fishermen in the Carolinas sometimes catch it. There it's better known by its other name--blackfish.
But "tripletail" has a better ring, doesn't it? That arises from the positions of the dorsal and anal fins, which are about the same size and shape as the tail fin. So they give the illusion that the fish has three tails.
Tripletail is an exceptional good eating fish. Unfortunately, there's no mass commercial catch of it. Because it's either line-caught or turns up as a bycatch in shrimp nets, it's not widely or regularly available. (Otherwise, it would turn up higher on this list.) Only restaurants that actively work the market every day buy it. In fact, finding tripletail on a menu usually means you're in a pretty good place.
Although tripletail is a moderately big fish--some ten inches wide and about a foot and a half long--its fillets remind me a lot of those of the much smaller speckled trout. In fact, I find the flavor similar, too.
As with trout, tripletail seems to be best cooked in the saute pan and served with a sauce on the buttery end of the spectrum. It can also be blackened or bronzed. (K-Paul's used to have some fun by calling it "reddened blackfish.") However, its texture makes it tend to fall apart on a grill. The flavor is excellent, and you shouldn't hesitate to order tripletail wherever and whenever you find it.
