Diet of the Oarfish

Oarfish, in the fish family Regalecidae, are the longest boned fish known to man. The fish received its name due to the rowing motion it makes when it swims. Although the oarfish looks threatening, its main food sources are plankton and other small animals. Rarely seen by humans, this fish poses virtually no threat to people.

Description

These magnificent fish are much longer than most fish, ranging in length from 10 to 36 feet long. Unlike most fish, the oarfish does not have scales; instead, it is covered by a layer of silver guanine. The body is long and thin, with a long dorsal fin that reaches from the top of the head to the end of the tail. (ref 1) The oarfishs skin is a silver-like blue and covered with blotches and other markings. It has large eyes and a protruding mouth.

Habitat

Oarfish are found in the Atlantic Ocean, the Mediterranean Sea and the Pacific Ocean. This fish lives far below the ocean surface, sometimes at depths of over 3,000 feet. A typical oarfish lives just over 650 feet from the oceans surface. Live oarfish are rarely seen in their habitat and are usually only spotted near the oceans surface when they are dying. In February of 2010, an oarfish was captured on film alive in its natural setting in the Gulf of Mexico.

Food Sources

Oarfish have no teeth, so they rely on small creatures like plankton, crustaceans and squid to survive. One type of zooplankton found in the oarfishs diet is krill, which are extremely small creatures that resemble shrimp. Krill travel in groups of millions, making it easy for the oarfish to scoop them up. According to the Florida Museum of Natural History, an oarfish found near California had 10,000 krill in its digestive system.

Catching Prey

Because of the absence of teeth, the oarfish must use a different method to ingest its prey. Inside of its mouth are specialized gill rakes that strain water, separating its prey. Gill rakes or rakers are shaped like tiny combs and protrude from the gill arches. Although the oarfish typically swims in a horizontal motion, it is thought it also swims vertically to search for and trap prey.

Human Association

The oarfish is not a fish that humans catch for food because its meat is jelly-like and inedible. Some fisherman attempt to catch the oarfish as a game fish. Posing little or no threat to humans, the oarfish is rarely seen alive and lives too deep in the ocean for regular human contact. In ancient times, mariners often drew pictures of dead oarfish found on the shores, which is considered to be the reason for sea serpent reports during that time period.