Ophiocoma scolopendrina

Lore & Background

Ophiocoma scolopendrina belongs to the phylum of echinoderms, which includes sea urchins, sea cucumbers, and sea stars. Its dorsal disc and arm plates vary from variegated black to pale brown and are irregularly banded. The species can be found in the Red Sea, the tropical Indo-Pacific region, Taiwan, Eastern Africa, Southeastern Polynesia, the Marshall Islands, and Madagascar. They live in crevices and under boulders of intertidal reef platforms in the upper and middle eulittoral, and have also been seen underneath coral rubble. They hide amongst concealing vegetation during surface-film feeding and live primarily in shallow water strictly in the intertidal.

Reader's Guide

Ophiocoma scolopendrina is significant for its specialized feeding adaptation, which allows it to consume neuston and detrital particles from the sea surface during low and flooding tides. Unlike other brittle stars, it becomes fully exposed during feeding, anchoring one arm to the substratum or vegetation while using two to four arms to sweep the surface. Food is trapped in mucus-covered spines and transferred to the mouth. Outside of flooding tide, it engages in microphagous suspension and deposit-feeding common to other Ophiocoma species. The species reproduces continuously throughout the year, with ovarian substances noted to induce male spawn. It has planktonic planktotrophic larvae and spawns in large numbers. Regeneration of arms is vital, with an average rate of 0.4 mm/day; breakage is typically observed in the top third of the arm. The species also engages in a heterospecific symbiotic relationship with juveniles of Ophiomastix annulosa in Okinawa, Japan, considered a form of brood parasitism.

Did You Know?

• Ophiocoma scolopendrina uses its arms to sweep the sea surface and trap food, a unique feeding method among Ophiocoma brittle stars.
• Adult females contain an estimated 12 × 10⁵ premature oocytes and produce gametes throughout their lives.
• The species has a symbiotic relationship with juveniles of Ophiomastix annulosa, which attach to the bursae of the host.
• Arm regeneration occurs at an average rate of 0.4 mm/day.