TilefishesMalacanthidae

The family is named after a fish that the 🇺🇸 United States believed it had watched die out over a single winter.

In 1882 ships crossing the shelf off New England ran for days through floating dead tilefish. A cold intrusion had reached the narrow strip of warm water on the outer shelf where the great northern tilefish lived, a species described only three years earlier, and the estimated kill ran past a billion animals. The fish was written off. It reappeared roughly a decade later and the population rebuilt itself, and the episode is still the clearest statement anyone has of what a tilefish is: an animal with one address and nowhere else to be.

That is the thread through the whole family. A tilefish lives in shelter it made itself, in ground that offers none, whether that is a burrow cut into shelf clay or a mound of broken rubble carried out onto open sand one piece at a time. The two species here do the second version, out on the flats below the reef, and their own pages take the building and the exposure apart.

The body is built for the trip home. It is elongate, with a long unbroken dorsal and anal fin and a single spine on the gill cover, and it swims in straight lines. A sand tilefish hovers a body length above its entrance picking small animals out of the current, and every decision it makes is measured against the distance back down the hole. They are long-lived for the size, too: the northern species has been aged past forty years from the growth rings in its ear bones.

Two are listed here. On an open sand flat they are usually the only fish in sight, which is a good deal less comfortable than it sounds.