The shiner perch (''Cymatogaster aggregata'') is a common surfperch found in estuaries, lagoons, and coastal streams along the Pacific coast from

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

. It is the sole member of its genus. The shiner perch is also known as seven-eleven and shiner seaperch.

Description

Shiner perch is similar to tule perch; it is 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 perch is distinguished from tule perch by having fewer

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

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 moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

has 3 spines followed by 22–25 rays. Shiner perch can reach a maximum length of , but are most commonly under in

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

Habitat and ecology

Shiner perch range from Punta Baja, Northern

, to Saint John Baptist Bay near Sitka in Southeastern

. It is one of the most common fish in the bays and estuaries of its range, favoring beds of eelgrass, and often accumulating around piers as well. While typically residing in shallow waters, it has been observed at depths up to . It can also live in

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary ...

s. It primarily feeds on

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

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 (living in the water column), some are benthos, benthic (living on the sedimen ...

s and gammarid amphipods, but has also been observed to feed on bottom species like small

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

marine worm Any worm that lives in a ocean, marine environment (biophysical), environment is considered a sea or marine worm. Marine worms are found in several different phylum (biology), phyla, including the Platyhelminthes, Nematoda, Annelida (segmented ...

s, and

mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

. It also feeds on fish eggs. Cymatogaster aggregata female

Fishery

Due to its small size, there is a very limited targeted fishery for the shiner perch, with an average commercial catch of per year. It is often taken incidentally or for bait at piers, and is one of the most, if not the most, commonly caught fish out of west coast piers. The shiner perch is often also used in

oriental The Orient is a term referring to the East in relation to Europe, traditionally comprising anything belonging to the Eastern world. It is the antonym of the term ''Occident'', which refers to the Western world. In English, it is largely a meto ...

and other ethnic dishes, fried whole or dried out.

Parasitism

It is often found with parasitic isopods such as '' Elthusa californica'', feeding off of them from their opercular cavity of the gill chamber.

References

* * {{Authority control Embiotocidae Fish described in 1854