Bony fish · Perciformes · Embiotocidae

Shiner Perch

Cymatogaster aggregata

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

The shiner surfperch, a silvery, laterally compressed fish with three vertical yellow bars, very abundant in bays, around piers and in eelgrass beds along the west coast of North America. It feeds on small crustaceans and forms large shoals in shallow water.

Size

10 cm – 22 cm

Diet

Carnivore

Feeds mainly on other animals.

Social structure

Colony

Lives in large concentrations, often for breeding reasons.

Sighting difficulty

Easy

OceanCarnivore Colonial Fish Ocean

2countries

Fun facts

It does not lay eggs: it is viviparous and gives birth to large, fully formed young that swim from the first moment.
The males are born already sexually mature and can fertilise a female within days of birth, although the embryos do not begin to develop until months later.
It is one of the most widely used indicator species for the health of North American Pacific estuaries.
It is viviparous, something exceptional among temperate marine fishes: the embryos develop inside the female and are born fully formed, at a size that can reach a third of the mother's.
And it goes further: the embryo's fins are highly vascularised and absorb nutrients from the ovarian fluid, a mechanism comparable to that of a placenta.
Males are born already sexually mature and can mate in their first year, while females store the sperm for months before fertilisation takes place.
It forms large schools in estuaries and under piers, and is one of the most abundant and best-studied species of the Pacific's eelgrass meadows.

Life cycle & biology

Skeleton type: Vertebrate - internal bony skeleton (fish)
Habitat & environment: Eelgrass beds, piers and bays of the north-eastern Pacific
Gestation / incubation: 3-6 months of internal gestation

Sources consulted: https://en.wikipedia.org/wiki/Shiner_perch