Ophiura luetkenii (Lyman 1860)

"Common on or just below the surface of silty sand or gravel substrata. Populations may be so dense that neighbours; arm tips overlap. Contact with one individual ay initiate waving of the arms throughout the population." (Lambert, Austin 2007)

"Disc: Up to 27 mm in diameter, pentagonal with flat, overlapping scales. The radial shields are almost pentagonal, longer than their width and about one-fifth the diameter of the disc; they are separated proximally by a wedge of scales scales and distally by a continuation of the dorsal arm plates. The arm combs consist of ten flat, squarish scales in tight contact with each other throughout their length.

Arms: About five to six times as long as the disc diameter. The dorsal arm plates overlap and are fan-shaped with a median ridge. The three arm spines each taper to a sharp tip; the upper spines at the base of the arm are equal to 1.5 joints in lenth and the others become shorter distally. The first ventral arm plate is triangular with a median groove, and the others are twice as wide as their length. Each podial pore has a small, bluntly pointed tentacle scale; large individuals have a second scale on the ventral arm plate.

Mouth: About ten spine-like apical oral papillae form a cluster around the mouth; each side of the jaw has five flat lateral oral papillae opposed by the three pointed papillae on the first ventral arm plate. The oral shield is a large, rounded pentagon, deeply notched on the sides. The adoral shields are narrow.

Colour: The dorsal disc surface varies but is usually mottled brown or grey. The arms often have brown or grey bands; they are white underneath. The arm spines are brown or grey at the base with white tips." (Lambert, Austin 2007)

"Limited to benthic organisms and carrion. Ophiura luetkenii can detect food from a distance and rapidly approach it using rowing motions of the arms. It captures food by quickly encircling it with an arm. It brings the arm loop to the jaws, which open and close as the food is pushed in by the oral tube feet. The jaws grip large pieces of flesh while the arms push it away to tear pieces off." (Lambert, Austin 2007)

How to Distinguish from Similar Species: O. sarsii is very similar but it has separated arm comb bristles with pointed tips and the animal is usually gray without stripes on the arms.

Biology/Natural History: May live in dense aggregations. These eat benthic animals and carrion. They capture food by racing after it using their arms, then looping an arm around it and bringing it to the mouth where the jaws tear off pieces of flesh while the arms pull the food away. Predators include the Dover sole, copper rockfish, and sand star Luidia foliolata. It has a rapid escape response from L. foliata.

Lives in or on the surface of silty sand or gravel.

Geographical Range: Bering Sea, Alaska to Baja California. They appear to be uncommon in California.

This arms of this brittle star insert into notches in the central disk, bordered by arm combs. The oral shields are widest near the middle of the shield. The spines of the arm combs are broad and blunt and touch one another from side to side, almost like small marginal plates along the edge of the arm notch. The radial shields are longer than wide and about 1/5 the diameter of the central disk. Proximally they are separated by a wedge of scales and distally they are separated by part of the dorsal arm plates. The arms are about 5-6x as long as wide. The large aboral plates on the arms are wedge-shaped and touch one another rather than having smaller plates in-between. The color is variable. Dorsally it is usually a mottled brown or gray, often with brown or gray bands on the arms. Ventrally they are white. The arm spines are brown or gray at the base with white tips

Depth Range: Intertidal to 1265 meters; usually subtidal at least 10 meters.