About Ophiocoma scolopendrina (Lamarck, 1816)
Ophiocoma scolopendrina, like other brittle stars, has long, thin arms extending from a small, disk-shaped body, and reaches roughly the size of an outstretched human hand. This species belongs to Echinodermata, the phylum that also includes sea urchins, sea cucumbers, and sea stars. The dorsal disc and dorsal arm plates range in color from variegated black to pale brown, and feature irregular banding. This brittle star can reach an arm length of approximately 13 centimeters, while its disc diameter can grow up to 25 millimeters. The sexes of this species can be distinguished by examining slits between the arms: these slits reveal white male spermaries and red female ovaries. Ophiocoma scolopendrina is distributed in the Red Sea, tropical Indo-Pacific region, Taiwan, Eastern Africa, Southeastern Polynesia, the Marshall Islands, and Madagascar. It typically occurs at a density of around 20 individuals per square meter. These brittle stars inhabit crevices and spaces under boulders on intertidal reef platforms in the upper and middle eulittoral zone, and have also been found under coral rubble. During surface-film feeding, they usually hide among concealing vegetation. They primarily live in shallow intertidal areas, and are often seen sweeping their arms over sand or coral substrates. Ovarian substances from females are known to induce spawning in males. Each adult female contains an estimated 12 × 10⁵ premature oocytes. Current research suggests that all adult Ophiocoma scolopendrina produce gametes for the rest of their lives, and consistently produce gametes across all studied ages. This species reproduces continuously year-round: once gametes are present in the gonads, spawning can occur in any season. Ophiocoma scolopendrina produces planktonic, planktotrophic larvae, and has been observed spawning in large aggregations.
