Cabrillo Marine Aquarium

Giant Kelpfish

Heterostichus rostratus


Fun Facts

    The giant kelpfish can quickly change color during courtship or territorial displays.

    The species name “rostratus” means “long-nosed” in Latin.




The giant kelpfish is a type of bony fish that lives in the kelp forest, eelgrass beds, and at times in tidepools. Giant kelpfish occur from Baja California, Mexico to British Columbia, Canada. The body is elongate and shaped like a kelp blade. The head is pointed and the tail is forked. The color varies from olive-green to red to brown.

Giant kelpfish feed on small fishes, crustaceans, and mollusks. They live to about 5 years old and mature at about 1 to 1.5 years old. This fish reproduces by spawning (release of eggs and sperm into the water column). The eggs are adhesive, so when they settle they attach to algae. Females lay on average 700 eggs.

Giant kelpfish are usually found at the Aquarium in tank number 21 and 33.