Shiner perch (Cymatogaster aggregata)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Ovalentaria incertae sedis · Family: Embiotocidae · Genus: Cymatogaster.

Accepted name: Cymatogaster aggregata · Authority: Gibbons, 1854 · Taxonomic status: accepted · AphiaID: 280461.

Synonyms and superseded combinations recorded for this taxon: Cymatogaster aggregatus Gibbons, 1854; Cymatogaster gracilis Tarp, 1952; Metrogaster lineolatus Agassiz, 1861.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=280461 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Cymatogaster aggregata. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 20.299999237060547 cm · Common length: 11.5 cm · Depth range: 1–146 m · Habitat zone: demersal · Body shape: short and / or deep · Vulnerability index: 10.3 of 100 · Fishery importance: minor commercial · Aquarium trade: never/rarely.

FishBase notes: Usually in shallow water, around eelgrass beds, piers and pilings and commonly found in bays and quiet back waters (Ref. 2850). Also in calm areas of exposed coast (Ref. 2850). Enter estuaries and brackish waters (Ref. 114138) [noted from freshwaters in Ref. 2850, but it is unlikely or rarely]. Found in loose schools or aggregations (Ref. 2850, Ref. 114138). Young feed mainly on copepods, while adults eat various small crustaceans, mollusks, and algae (Ref. 27547). Viviparous, female carries the developing young (Ref. 205). Exhibit seasonal onshore-offshore movements (Ref. 27547).

Source: FishBase species summary (SpecCode 3626) — https://www.fishbase.se/summary/Cymatogaster-aggregata.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

173,954 georeferenced occurrence records for Cymatogaster aggregata are published through GBIF from 3 countries or marine areas. The map above plots 42 distinct locations from a sample of 3,000 records, omitting 45 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: United States of America (161,502); Canada (12,429); Mexico (23).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2389234) — https://www.gbif.org/occurrence/search?taxon_key=2389234&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=280461 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Cymatogaster aggregata Gibbons, 1854 as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 192929) — https://www.iucnredlist.org/species/192929/0; GBIF IUCN Red List category endpoint (taxonKey 2389234) — https://api.gbif.org/v1/species/2389234/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Shiner perch range from Punta Baja, Northern Baja California, to Saint John Baptist Bay near Sitka in Southeastern Alaska.

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 120 m. It can also live in brackish waters.

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 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 has 3 spines followed by 22–25 rays.

Shiner perch can reach a maximum length of 21 cm, but are most commonly under 10-15 cm in total length. Shiner perch mature soon after birth, but females often wait until one year of age before spawning. Breeding males can turn almost completely black.

It primarily feeds on zooplankton such as copepods and gammarid amphipods, but has also been observed to feed on bottom species like small crustaceans, marine worms, and mollusks. It also feeds on fish eggs.

Due to its small size, there is a very limited targeted fishery for the shiner perch, and it is usually taken incidentally or for bait. They are one of the most commonly caught fish out of West Coast piers, and are a popular catch for beginner anglers. The shiner perch is often also used in East-Asian and other ethnic dishes, fried whole or dried out.

The Regional Monitoring Program for Water Quality in San Francisco Bay has tested shiner perch tissue for contaminants, and found elevated levels of mercury and PCBs that make it unsafe for human consumption. As a result, the California Office of Environmental Health Hazard Assessment (OEHHA) has issued health advisories, encouraging people to avoid or reduce consumption of shiner perch and several other fish species from the Bay.

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

Source: Wikipedia: Shiner perch — https://en.wikipedia.org/wiki/Shiner_perch (CC BY-SA 4.0). Accessed 2026-09-23.