Redtail surfperch – Amphistichus rhodoterus

The Redtail Surfperch, scientifically known as Amphistichus rhodoterus, is a species of fish found along the Pacific coast of North America. This species is distinguished by its striking red tail fin, which sets it apart from other surfperch species. They are an integral part of the marine ecosystem, contributing to the intricate balance of life within the intertidal and shallow coastal waters they call home.

Description & Characteristics

Amphistichus rhodoterus is a relatively small fish, with a maximum size of 41.0 cm. Its body is elongated and slightly compressed, characterized by a dorsal fin that extends nearly the entire length of the back. The most defining feature, as the common name suggests, is the bright red tail fin, which provides a striking contrast against its generally silvery-grey body. Juveniles of Amphistichus rhodoterus are typically darker in color, transitioning to the characteristic adult coloration as they mature.

Habitat and Occurrence

Redtail Surfperch are commonly found in the intertidal and shallow coastal waters of the Pacific coast of North America. They are particularly prevalent in the nearshore areas, where they inhabit rocky reefs, kelp forests, and sandy bottoms. Their depth range typically extends from the surface to a maximum of 7.0 meters, indicating a preference for relatively shallow waters. This makes Amphistichus rhodoterus a frequent inhabitant of the neritic zone, a marine zone that spans from the shoreline to the edge of the continental shelf.

Taxonomy

Amphistichus rhodoterus is classified within the Class: Teleostei, Order: Ovalentaria incertae sedis, and Family: Embiotocidae. The Order Ovalentaria incertae sedis is a diverse group of fishes that includes a variety of species with different evolutionary relationships. The Family Embiotocidae, also known as surfperches, comprises a group of fishes that are uniquely adapted to the intertidal and nearshore environments of the Pacific coast of North America.

Feeding

Redtail Surfperch are primarily zooplankton feeders. Their diet consists mainly of small crustaceans, phytoplankton, and other tiny organisms that they filter from the water. This feeding strategy makes them important members of the marine food web, playing a role in the transfer of energy from microscopic organisms to larger predators.