Giant Kelpfish
Heterostichus rostratus
Physical Description
- Fish with a long and flattened body, shaped like a kelp blade.
- Coloring from light brown to green to purple, depending on the habitat. (In eelgrass, they can be bright green with thin silver stripes. In kelp beds, they can be brown-green like kelp). Can have wavy stripes on their sides.
- Long dorsal (back) fin, almost the entire length of body.
- Deeply forked tail fin.
- Can be up to 24 inches long.
- Juvenile fish can change colors rapidly. Adult females can change colors, but more slowly. Adult males cannot.
Range
- British Columbia to southern Baja California, Mexico.
- Uncommon north of Point Conception.
Habitat
- Live in shallow water.
- Live in rocky areas, kelp beds, eelgrass, and tide pools.
- Found near piers with heavy kelp growth.
Reproduction
- Females often lay 700 eggs at a time.
- Females deposit eggs into algal nests.
- Males vigorously guard nests for up to two weeks until eggs hatch.
- Larvae are well-developed when they hatch and stay in plankton in large schools for several weeks.
Diet
- Small fishes, crustaceans, mollusks.
Predators
- Octopuses.
Interesting Facts
- They can quickly change colors during courtship or territorial displays.
- They can also quickly change colors to camouflage in their environment.
- Larval kelpfish sometimes school with transparent mysid shrimp.
Sources: Pierfishing.com; Cabrillo Marine Aquarium; fossweb.com; Seafood Watch
Photo: Kevin Lee