CobiaRachycentridae

There is one cobia. Not one in this sea, one on the planet: a single species that is the only member of its genus and the only member of its family, with no close look-alike anywhere.

The wild animal is a brown torpedo up to about two meters long, with a broad flattened head and a dark stripe running the length of the flank. Despite the open-water build it is not much of a fish chaser. Its older name is crab-eater and it earns it, coming up with a stomach full of swimming crabs, with shrimp, squid and whatever fish it can corner making up the rest. It works structure rather than empty blue: wrecks, buoys, channel markers, floating debris, anything that concentrates prey, and it will drop in behind a large ray or shark and use it as moving cover.

The second career is stranger. For a fish almost nobody sees, cobia is one of the species offshore aquaculture has settled on. It spawns in captivity without much persuasion, tolerates crowding, takes pellets, and puts on weight in a sea cage faster than nearly anything else farmed in salt water, so cages from 🇹🇼 Taiwan and Vietnam to 🇵🇦 Panama and the Caribbean are stocked with it. There is a decent chance that most cobia alive at this moment have never been in open water.

One species is listed here and encounters are uncommon. A cobia in the 🌊 Red Sea is usually a single fish that appears at the edge of visibility over a wreck or a sand flat, reads for a second as something more alarming than it is, and keeps going.