Luidia foliolata Grube 1866

How to Distinguish from Similar Species: The only other stars with 5 rays and conspicuous marginal plates have marginal plates easily visible from above. Mediaster aequalis has no spines on its marginal plates and has suckers on the tube feet.

Sand and mud, nearly always subtidal, often half buried.

Geographical Range: Southeast Alaska to San Diego, CA

Depth Range: 12 to 600 m

This fairly large asteroid has 5 rays and conspicuous marginal plates which are not visible from the aboral side. Each plate has several spines. The tube feet have no suckers. The ones I have found have been a dirty gray-brown color. Up to 40 cm diameter

Biology/Natural History: Pointed tube feet without suckers are common on seastars which live on sand instead of rocks. This species seems very fragile--I have captured a number of specimens by otter trawl but all have been fragmented. This star is reported to eat the sea cucumber Cucumaria miniata. This species burrows. It has a very leaky outer surface, and allows seawater fluids to pass readily through its surface. However, it tends to be hyperosmotic. It appears to make extensive use of seawater intake through its madreporite to maintain internal fluid balance.