The velcro star is a large starfish, growing to a maximum diameter of 100 cm (39 in), but is usually considerably smaller.

Rows of large spines run down the arms, each one surrounded by a ring of 30-40 pedicellariae, tiny pincer-like structures.

[3] The velcro star occurs on the Pacific coast of North America, from Kodiak Island, Alaska, to Southern California.

When alert to movement in the water nearby, the rings of pedicellariae are extended, ready for action.

If anything touches its aboral (upper) surface, the starfish reacts by snapping shut the pedicellariae in the vicinity of the stimulus.