Sunburst Anemone

The sunburst anemone is a solitary anemone that averages 12 cm (4.7 in) but can grow up to 25 cm (9.8 in) wide, much larger than the aggregating anemone.

The column is pale green to white in color and is twice as long as its width when extended. The column has numerous sticky protuberances (called verrucae) arranged in vertical rows to which gravel and shell fragments adhere. The oral disc is radially striped and has five rings of thick, pointed feeding tentacles. Tentacles are pale with the tips colored in pink, blue or lavender.

The starburst anemone's tentacles and oral disk display varied color patterns. Their tentacle tips are pale because the anemones frequently shelter under rocks or in shaded areas, and this lack of light prevents the development of green pigments. Additionally, the striped patterns on the tentacles are a result of genetic differentiation.

The sunburst anemone is found in the north west Pacific Ocean. In the United States it occurs between central California and Baja California. It lives in the lower intertidal zone in rocky habitats, often in the shelter of cracks and crevices. It also occurs in the subtidal, often in kelp forests, to depths of at least 20 m (70 ft). When the tide is out it is often concealed by shell fragments and other particles that adhere to the column, which folds into an encrusted ball. The encrusted column may serve as camouflage from predators as well as protection from solar radiation and desiccation.

As a sessile suspension feeder, the sunburst anemone relies on prey that comes into contact with its stinging tentacles. Its diet includes mussels, sea urchins, snails, small fish, and organic flotsam. Once captured, prey is directed to the mouth at the center of its oral disc. This same opening is also used to excrete waste when food is digested. In addition, the sunburst anemone benefits from a symbiotic relationship with photosynthetic algae.