Food and Feeding Mechanisms: Ophiuroidea

Ophiuroid food and feeding are now fairly well documented and, although gaps remain in our knowledge, it is possible to attempt some generalizations. Scavenging is distinguished from deposit feeding on the basis of particle size: the particles in deposit feeding are small enough to be passed solely by the tube-feet whereas scavenged food requires arm or whole body movements. Less specialized deposit feeding in which particles are simply picked up from the surface of the substratum by the tube-feet and transferred from one tube-foot to the next towards the mouth, occurs in all but the most specialized ophiurids. An interesting type of deposit feeding surface film feeding has been described in Ophiocoma scolopendrina in which individuals, which live in tide pools, extend their arms on a rising tide and collect particles from the surface film. Carnivorous feeding is, by definition, selective in terms of the nutritive value of the food and only microphagous feeding could be unselective in this sense.