Aquarium of the Pacific - Online Learning Center - Species Print Sheet
Silver surfperch are native to the eastern Pacific coast with the exception of two species found off the coast of Japan. There are 20 marine and one freshwater species in the family Embiotocidae with about 15 marine and the one lone freshwater species (tule perch, Hysterocarpus traski), being found in California. They are uniquely different from most other bony fishes in that they do not broadcast spawn eggs and sperm. Fertilization is internal and the females give birth to live, highly developed, free swimming young.
At the Aquarium
The Aquarium habitat for silver surfperch is in the Northern Pacific Gallery.
Southern British Columbia, Canada, to northern Baja, Mexico.
They are found inshore, around piers and rocks, and where there are surf and sandy areas at depths from the surfline out to110 m (360 ft).
Silver surfperch have a strongly compressed, oval body, an upward slanting mouth, relatively large eyes, and a single continuous dorsal fin with slightly longer spines than the soft rays. Their upper body is silver-gray to greenish and silver below. They sometimes have dusky bars on their sides. Their forked caudal fin is often pinkish in color and their dorsal and caudal fins dark edged. Occasionally they have an orange spot on their anal fin. Their pelvic fins have no color and do not have a dark edge, which helps distinguish them from the similar species, the walleye surfperch, Hyperprosopon elliptum.
These fish can grow to 27 cm (10.5 in) in length but they are usually much smaller. Males grow more slowly than females and are not as long.
Silver surfperch eat small clams, gammarid amphipods (small shrimp-like animals), sand crabs, and small fishes.
Females mature between two and three years of age when 18 to 20 cm (7-8 in) in length and males between 1-3 years. Like all surfperch, silver surfperch are viviparous, that is, they do not lay eggs but bear live young.
The male silver surfperch approaches the female from below. Both swim together for two or three seconds, separate, and then come back together again. This ‘dance’ can be repeated several times. Internal fertilization is aided by a thickening in front of the male’s anal fin. This “nipple” is used to transfer milt into the female. The female surfperch stores the male’s sperm in her body until the ova are mature (sometimes up to 6 months)—then, fertilization takes place. The 4 to 16 eggs are incubated and hatch inside the female’s body. The female continues to carry the developing larvae for nearly 12 months. When she gives birth, the young emerge as fully-developed, miniature replicas of the adults.
Silver surfperch swim in loose schools.
These fish, especially juveniles, are often found swimming in the surf. The strongly compressed body structure of surfperches is important to their being able to withstand the surf’s rough action.
The relatively large size of newborn silver surfperch improves their chances of survival.
They live for about seven years.
In spite of their small size, silver surfperch are an important recreational fish in California, ranking among the top ten in numbers caught. They have no commercial value.
California coastal waters are considered to be the center of evolution of the surfperch family.
Male shiner surfperch, Cymatogaster aggregate, reach sexual maturity almost immediately after birth. Females can be inseminated soon after birth, carrying the sperm in their ovaries until the time is suitable for fertilization to take place.