Are Basket Stars, Sea Stars?

The basket star, Gorgonocephalus eucnemis, is basically a fancy brittle star. After attaching to a rock or other firm substrate, an adult basket star will spread its five intricately branched arms into the water to catch tiny zooplankton (crustaceans, arrow worms, and sometimes fish larvae and jellies). Hooks on the arms snag the prey items which are then rolled up in mucus strings within the tiny branchlets. These branchlets curl down to the animal’s underside where they move the prey masses to the star-shaped mouth. Here, the teeth-like structures comb off the prey and associated mucus from the branchlets into the stomach. The video below shows how a basket star uses its arms to catch and eat krill.

Not a sea star, this echinoderm is different in several ways from its cousins. Its arms, not its tube feet, are used to move the animal; the tiny tube feet may help transport prey to the mouth. The stomach does not come out of the star-shaped mouth which is lined with numerous combing teeth. And, unlike sea stars, basket stars have two openings at the base of each arm which contain both the gills and the gonads.

In this short video clip, you get a closer look at the basket star using its arms to pull food into its star-shaped mouth.

Come to the Life on the Edge exhibit at the Seattle Aquarium and see a basket star up close!

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