The redtail surfperch (Amphistichus rhodoterus) is a marine fish that inhabits the near-shore and estuarine waters of North American Pacific coasts.

[2] The body is light colored, white to silver, with vertical marks or bars and red or pink fins (e. g. dorsal, anal and tail).

The lateral line starts behind the gill cove and runs high on the back parallel to the edge of the body above the pectoral fin to the tail.

Amphistichus rhodoterus are iteroparous (i.e. reproducing multiple times during their life) with females giving birth annually after reaching sexual maturity at 3 or 4 years of age.

[5][7][2] Females along the central Oregon coast contain fertilized eggs near the first of the year, gestate for 8 months, and give birth in August and September.

[5][2] Northern California populations of redtail surfperch have a similar reproductive schedule, except that parturition (live birth) starts in July.

Redtail surfperch can move long distances along sandy beaches and coastlines, however migration around larger headlands like Cape Arago in southern Oregon has not been documented.

Sea lions have been observed surfing in waves just offshore of redtail surfperch fishing beaches but not as close in-shore as harbor seals.

[2] Stranded-decaying kelp, seagrass, invasive marsh grass as well as plankton and bacteria contribute energy and nutrients to this beach ecosystem.

Female fish containing developing embryos dominate the redtail surfperch caught inside estuaries upstream from the entrance and jetties.