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Family: Ophiocomidae
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Bocas Species Database Distribution: Caribbean, Texas. Natural History Notes: This species is one of the most abundant brittle stars on corals reefs in the Caribbean. like O. echinata and O. pumila, O. wendtii is common beneath coral and rubble, but this species tends to occupy higher, longer crevices than its congeners. Between dusk and dawn, the brittle star extends two or three arms from its burrow to feed on floating particles, algal epiphytes and benthic "scuzz". Food pellets are observed on the arms during the day as well, suggesting that individuals suspension or deposit feed within their burrows. Individuals change color on a daily cycle, shifting from brownish during the day to grayish brown with black arm bands and disk markings at night. Its color changing is related to its light-sensitivity, which is mediated by expanded peripheral trabeculae (EPT) that overlie sensory cells located within the external ossicles of the arm. Several species of West Indian reef fish prey upon the brittle star, and arm-cropping predators exert an impact as well, with 30% of arms in a population regenerating at any time. Depth: Usually less than 1-27 m, but reported from 384 m. Characteristics: O. wendtii grows to 35 mm in disk diameter and has arms longer than 176 mm. It is black to reddish brown and has banded arm tips. The most dorsal arm spines are the longest, and are usually equal in length to four to five arm joints. It has a single tentacle scale on the joints beyond the disk, two arm spines on the first and three on the second arm joints, and alternating numbers of spines on successive arm joints. Its red tube feet make the ventral surface of the arms appear reddish. Juveniles look very different from adults and may be mistaken for amphiurids or ophiacanthids. The have only a pair of papillae at the tip of the jaw, which is incorporated into a cluster of dental papillae as the individual grows. The smallest individuals have scattered, short spines on the disk. The disk is black and the arms are solid orange or salmon-colored. |