Kelp Surfperch
Author: Lachlan Breen
Scientific name: Brachyistius frenatus
Identification: Kelp Surfperch, also commonly known as Kelp Perch, are a species of surfperch of the family Embiotocidae found throughout the Pacific Northwest. They can be differentiated from other surfperch by their uniform golden brown colour, small adult size, and noticeable indent in head profile.
Habitat: As the name suggests, Kelp Perch are commonly found in giant kelp forests, usually high up in the “canopy”. Throughout the Salish Sea, they can also be found in and around algae and marine grasses, as well as under docks and pilings. Occurring intertidally to no more than 76 metres deep, the Kelp Perch’s range extends from Puget Sound to southern Alaska, as well as from Central California to Mexico.
Diet: Kelp Perch feed on zooplankton and various small invertebrates found around kelp. These include small shrimp and crabs, polychaetes, and amphipods, among others. Juvenile Kelp Perch feed almost exclusively on zooplankton, including larval crustaceans and the eggs of other fish. Interestingly, Kelp Perch have been documented acting as “cleaner” fish, removing other, larger, fish of their parasites. However, this behaviour has only been observed in the southern portion of their range, from California to Baja California.
Predators: Kelp Surfperch are preyed upon by many other marine animals, including seals and sea lions, large predatory fish, such as rockfish and lingcod, and seabirds, including gulls and cormorants. While some surfperch species are commercially fished as food fish, due to the small size of Kelp Perch they are rarely consumed by people, as they yield little meat.
Reproduction: Unlike many other bony fish species, all surfperch (including Kelp Perch) are viviparous. This means that only the male fish release sperm, and internal fertilization occurs inside the female. Embryonic young develop for several months until they are born, up to 50 at a time.. When born, 3cm Kelp Perch look just like miniature adults, and are fully formed, giving them an increased chance of survival to adulthood.
References
Lamb, A., & Edgell, P. (1986). Coastal Fishes of the Pacific Northwest (1st ed.). Harbour Publishing.
Kelp Surfperch – Monterey Scuba board. (2024, May 12). Monterey Scuba Board. https://montereyscubaboard.com/species/kelp-surfperch/
Carpenter, K., & STRI, R. R. (2018, October 12). IUCN Red List of Threatened Species: Brachyistius frenatus. IUCN Red List of Threatened Species; Name. https://www.iucnredlist.org/species/141481252/141781353#assessment-information