Isla San Francisco's tide pools yield a variety of marine invertebrates. This "sun star," Heliaster kubinjii, is one of two species of Heliaster in the Gulf of California.
Sea stars use a "hydraulic" system to pump water into their tube feet, which are tiny suckers under each arm. The tube feet are used by the sea stars to move about and to grasp their prey. A star feeds by turning its stomach inside-out and engulfing its prey, digesting it outside its own body. Once the clam or snail has been digested, the star reclaims its stomach.
Other invertebrates found in the water here today included a beautiful Annette's Cowry, three species of sea urchins, fire worms, a flame scallop, three species of brittle stars, two species of porcelain crabs, a hermit crab, a small Gulf star, and a sea cucumber.
