The shiner perch (''Cymatogaster aggregata'') is a common

surfperch The surfperches are a family of perciform fishes, the Embiotocidae. They are mainly found in northeast Pacific Ocean (as far south as Baja California), but a few species (genera '' Ditrema'' and '' Neoditrema'') are found in the northwest Pacifi ...

found in estuaries, lagoons, and coastal streams along the Pacific coast from

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

. It is the sole member of its genus. The shiner perch is also known as seven-eleven and shiner seaperch.https://www.collinsdictionary.com/us/dictionary/english/shiner-perch Cymatogaster aggregata female

Shiner perches are similar to

tule perch The tule perch ''Hysterocarpus traskii'' is a surfperch ( Embiotocidae) native to the rivers and estuaries of central California, United States of America. It is the sole member of its genus, and the only freshwater surfperch. The tule perch is ...

es, deep-bodied with a dusky greenish back and silvery sides that have a pattern combining fine horizontal bars with three broad yellow vertical bars. Breeding males turn almost entirely black, the barred pattern being obscured by dark speckles. Shiner perches are distinguished from tule perches by having fewer

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

spines, just 8–9 vs the 15–19 of the tule perch. The rayed part of the dorsal fin has 18 to 23 rays. The

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

has 3 spines followed by 22–25 rays. They are one of the most common fish in the bays and estuaries of their range, favoring beds of

eelgrass Eelgrass is a common name for several plants and may refer to: * ''Zostera'', marine eelgrass * ''Vallisneria ''Vallisneria'' (named in honor of Antonio Vallisneri) is a genus of freshwater aquatic plant, commonly called eelgrass, tape grass o ...

, and often accumulating around piers as well. They feed on

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

such as

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

s, but have been observed to bottom feed as well. They are often found with parasitic isopods such as the Elthusa ''californica'' feeding off of them from their opercular cavity of the gill chamber.

References

* Peter B. Moyle, ''Inland Fishes of California'' (University of California Press, 2002), pp. 428–429 * Embiotocidae Fish described in 1854 {{ray-finned fish-stub