SandperchPinguipedidae

On open sand there is nothing to hide behind, so a sandperch does not try.

It sits out in the middle of a bare patch with the front half of its body lifted clear of the bottom on stiff pelvic fins, which is the posture the species pages describe, and from a distance it looks like a fish that has not noticed you. It has. The head is flattened and the eyes are set high on top of it, so the whole hemisphere of water above is covered without the animal moving anything at all, and the danger on a sand flat is always overhead. The mouth points the other way, low and forward at the ground where the food is: small crustaceans, worms, brittle stars, the occasional small fish, taken in a single short dash from a standing start. A sandperch never cruises. It sits, it goes, it sits again a meter away.

The lips are thick and there are proper canine teeth behind them, which is more weaponry than a fish of this size normally carries and a good clue to what it is. Sandperches are ambush predators on ground that offers an ambush predator nothing, and the answer they found was to be visible and to be still.

Their social arrangement is the reef standard, run on sand: a male holds an area containing several females and patrols it, and when he is removed the largest female becomes the next male. The wrasse page has the mechanics of that change and the anthias page has the arithmetic of who owns what.

In practice they are misidentified constantly, usually as gobies or as lizardfishes, because all three sit on sand. A lizardfish lies flat with its belly on the bottom and a mouth full of needle teeth. A goby is smaller and holds on with a disc under its chin. A sandperch props itself up, watches upward, and has a face like a small grouper. Two are listed here, which is the whole of this heading: the family is much larger in the Pacific and this sea gets a fraction of it. The speckled sandperch is the one you will actually meet, and it is on almost every sand patch beside almost every reef.