Opahs and Relatives: Lampridiformes

Scientists do not know much about opahs and their relatives. The long forms hold themselves straight up and down in the water. The other forms swim belly down and head forward the way most fish do. Opahs are powerful swimmers, using their large pectoral (PECK-ter-uhl) fins to move themselves forward. The pectoral fins are the front pair, corresponding to the front legs of four-footed animals. One opah relative delivers a mild electric shock when handled. Other species release ink when disturbed.

Opahs and their relatives probably scatter their eggs. The eggs are large and brightly colored, usually red, pink, or amber. Fertilized (FUR-teh-lyzed) eggs, or those that have been penetrated by sperm, develop in surface waters for approximately three weeks. At hatching, larvae (LAR-vee), or the early stage that must change form before becoming an adult, have fully developed mouths and digestive tracts, are able to take in food, and begin immediately to feed on plankton.