Identification Photos: Ochre Starfish, Pisaster ochraceous: The Ochre Starfish is a cold water species that is the most common large intertidal sea star that occurs in great numbers on mussel beds on exposed coasts ranging from Alaska to Cedros Island, Baja California, Mexico.

Based on diet the Ochre Starfish varies in color from yellow, to orange, to brown, to reddish, to purple.

The Ochre Starfish has a radial symmetry with a good-sized middle disk with five stout arms. The upper side of the disk has white spines in a pentagonal pattern and the wingspan is between 10 and 18 inches.

The Ochre Starfish is found in all wave-washed rocky shore areas in shallow water up to depths of 300 feet. It is capable of surviving strong surges, big temperature changes, salinity dilutions by rainfall, and desiccation, being able to lose up to 30 percent of its body fluids during up to 8 hours out the water. The Ochre Starfish feeds primarily on mussels, chitons and limpets. In turn it is preyed upon by Sea Otters and Sea Gulls. It has an average life span of between 4 and 6 years. The Ochre Starfish has no known practical use for humans.

The Ochre Starfish is a common member of the Echinoderm phylum of marine animals and is a member of the Asteroidea Class and the Asteriidae Family. The Echinoderms include Brittle Stars, Sea Cucumbers, Sea Lilies, Starfish and Urchins and are of great scientific interest because, via fossil records, they date to the Cambrian Age (over 500 million years ago) with species numbering 7,000 living and 13,000 extinct. The Starfish or Sea Stars have a unique water-vascular system that uses hydraulic power to operate a multitude of tine tube feet that are used in locomotion and food capture. Some feed via inserting the stomach out through the mouth surrounding the prey, secreting enzymes to digest the food and then retracting the stomach when finished eating. They exist from intertidal zones to depths of 30,000 feet with 1,500 species known globally. The bodies are flattened, flexible and covered with colored skin.

Ochre Starfish, Pisaster ochraceous: Caught off the Oceanside Pier, Oceanside, Calif., May 2008. Size 10 inches. A “catch and release.” Description and photo courtesy of John Snow.