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Family: Ophiocomidae
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Bocas Species Database Habitat: All reef zones, but more common in shallow habitats. Distribution: Caribbean, Africa. Natural History Notes: O. pumila is one of the most abundant brittle stars on many shallow reefs in the Caribbean. Large individuals live in rock crevices and under corals or rubble. Smaller individuals are frequently found in branching corals, and the smallest O. pumila live in clumps of algae with other brittle star species. Feeding activity is nocturnal. Individuals extend two or three arms from crevices and will suspension or deposit feed. Stomach contents include calcareous particles and fleshy algae. In Panama, O. pumila spawns year-round. Its eggs are about 0.07 mm in diameter and are pinkish red. The species has an armless, secondary larval stage and is capable of long-distance dispersal. O. pumila's dispersal ability may explain its presence on both sides of the Atlantic. Several predators, including wrasses, parrotfish, and mojarras, will consume the whole brittle star. Other predators, such as fish and crabs, only take arms, but these have a significant impact as well; an estimated 35% of the arms in a O. pumila population are regenerating at any given time. Depth: Usually, intertidal to 24 m, but reported from 368 Characteristics: The disk diameter of a large individual is 17 mm and arms grow to 140 mm. This is the smallest, most delicate, and most pallid Caribbean Ophiocoma (its species name means dwarf). It has a granule-covered disk, with elongate granules along the disk's edge. Like other Ophiocoma, its jaws have both dental and oral papillae. The species can be distinguished from its cogeners by several characteristics of its arm spines: The largest, longest arm spine is one of the middle arm spines; the first and second arm joints have three arm spines; except on a few proximal arm joints, the species has single tentacle scales. The disk of the species is a variegated brown, reddish brown, tan, yellow, green, gray, or white. Its arms are banded and the tube feet are nearly transparent. Small individuals are often a bold green and red. Arm tips of small individuals and regenerating arms of adults are often green. |