The pineapplefish, Cleidopus gloriamaris, is a species of fish in the family Monocentridae, and the sole member of its genus. It is also known as the knightfish or the coat-of-mail fish, due to the armor-like scales covering its body, and the port-and-starboard light fish, as it has a pair of bioluminescent organs that are reminiscent of navigation lights on ships.^[1] Its specific epithet is from the Latin gloria and maris, meaning “glory of the sea.” […]

The pineapplefish grows up to 22 cm (8.7 in) long.^[4] It has a plump, rounded body almost completely covered in large, rough scales with sharp, backward-pointing spines. The head is large, with mucous pits bordered by rough ridges, and is armored with heavy bone. The snout is blunt and overhangs the wide mouth. The teeth are tiny and thin, present on the jaws, palatine, and vomer.

Due to its small fins and rigid armor, the pineapplefish is a weak swimmer.^[2] A nocturnal species, it may be found inside caves and under rocky ledges during the day.^[7] In the Fly Point Halifax Park Aquatic Preserve, New South Wales, a small group of pineapplefish has been documented under the same ledge for at least 7 years, and another group under a different ledge for 3 years.^[8] At night, this species ventures out onto sandy flats to feed, using its light organs to illuminate small shrimp.

(From Wikipedia, 03/05/11)