Opisthonema

Opisthonema

Opisthonema oglinum, commonly known as the Atlantic thread herring

Opisthonema is a genus of ray-finned fish in the family Clupeidae, commonly known as herrings. This genus is notable for its species that inhabit the coastal waters of the Atlantic Ocean and the Pacific Ocean.

Description

Members of the genus Opisthonema are characterized by their elongated bodies and distinctive thread-like extensions of the dorsal fin, which is a feature that gives them their common name, "thread herrings." These fish typically have a silvery appearance with a bluish or greenish tint on their dorsal side, which helps them blend into their aquatic environment.

Habitat and Distribution

Opisthonema species are primarily found in the tropical and subtropical regions of the Atlantic and Pacific Oceans. They are commonly found in coastal waters, often forming large schools. These fish are pelagic, meaning they inhabit the water column rather than the sea floor.

Species

The genus Opisthonema includes several species, with the most well-known being:

• Opisthonema oglinum - Commonly known as the Atlantic thread herring, this species is found along the western Atlantic coast from the United States to Brazil.
• Opisthonema libertate - Found in the eastern Pacific Ocean, from California to Peru.
• Opisthonema medirastre - Also found in the eastern Pacific, with a range similar to O. libertate.

Ecology

Opisthonema species play a significant role in the marine ecosystem as both prey and predator. They feed on plankton, including zooplankton and phytoplankton, and are an important food source for larger predatory fish, seabirds, and marine mammals.

Importance to Humans

These fish are of commercial importance in some regions, where they are caught for use as bait in fishing or for direct human consumption. They are also used in the production of fish meal and oil.

Related Pages

• Clupeidae
• Ray-finned fish
• Pelagic fish