Cusk-Eels and Relatives: Ophidiiformes

Physical characteristics: Pearlfish are long, slender, and eel-like. The skin is cloudy, almost clear, with silvery bands along the sides and black along the back. The cheeks are silver, and there are blotches of color at the bases of the dorsal and anal fins and on the head. The dorsal and anal fins extend almost the length of the body. There are Pearlfish live in the bodies of sea cucumbers during the day and exit at night to look for food. (©Chesher/Photo Researchers, Inc. Reproduced by permission.) no pelvic fins and usually no tail fin. The teeth on the upper jaw are small, and some are heart-shaped. The teeth on the lower jaw are larger and cone shaped. The swim bladder is separated into two parts.

Geographic range: Pearlfish live in the western Atlantic Ocean from Bermuda to Brazil.

Habitat: Pearlfish live in sea cucumbers, which usually live in shallow waters to about 98 feet (30 meters) on sandy bottoms or grass beds in warm lagoons near reefs.

Diet: Pearlfish eat crustaceans (krus-TAY-shuns), or water-dwelling animals that have jointed legs and a hard shell but no backbone, such as small shrimps and crabs.

Behavior and reproduction: Pearlfish live in the bodies of sea cucumbers during the day and exit at night to look for food and perhaps to spawn, or release eggs. Pearlfish deposit their eggs into a jellylike blob that floats at the surface. Eggs hatch in one to two days. Pearlfish larvae are remarkable in that they undergo two separate growth phases. In the first phase the larvae have a long, showy thread in front of the dorsal fin. These larvae are very long, about 7 inches (18 centimeters). In the second phase the larvae shrink to about half their original length.

Pearlfish and people: Pearlfish are rarely seen and are not fished commercially.

Conservation status: Pearlfish are not threatened or endangered. ∎