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Haystack Rock


Ochre Sea StarPisaster ochraceaus

Size: up to 14 inches across
Color: Red, brown, purple or ochre
juveniles are usually
gray with brown patches
Description: 4-7 stout arms covered with white 'spots.'

Photo Courtesy of Gary Hayes

These spots are microscopic pinchers keep sea stars free of settling larva, algae and other would-be squatters.) Just off from center there is also a large off-white to yellow spot that is the sieve plate--the main valve for letting water in and out of the sea stars vascular system.

Sea stars are omnivores--they'll eat just about anything. Their preferred prey are mussels, barnacles, clams, crabs, and chitons. They range from Sitka Alaska to near Baja, and are prey to gulls and beachcombers.

Sea StarA sea star population consists of separate sexes (male and female). They have a definite spawning period - March to June. Eggs and sperm are extruded from between the rays/arms and from the sea star's dorsal surface into water. Pisaster species do not brood their young. Rather, the eggs are fertilized in the water, not inside the sea star. Sea star embryos develop to swimming larvae, metamorphose and as new stars, measure less than 1 mm. Regeneration of arms (rays) is possible if some part of the central disc remains intact- regeneration of whole animal from an arm is not possible without some part of the central disc.

A sea star's growth varies with food availability, roughness of waters, etc. With a constant food supply and the right conditions, a sea star can feed continuously and increase its weight from two to 30 times in a year. The sea star's size is not related as much to age as it is to food availability. The Common Pacific Sea Star can survive at least 20 months without feeding.

Touch gently and NEVER move a sea star
Sea stars, or starfish are among the most popular residents of tidepools the world over. They are big, brightly-colored, and fairly easy to spot. They are also very much alive, despite appearances, and are important predators in the intertidal zone. Pulling sea stars off of rock or mussel beds might seem like a harmless way to get a closer look but that simple action can cause severe damage and even death.

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