General Description

Medium-sized species, disc covered in scales with some small spines along the margin and ventrally. Arms up to six times disc diameter with 3-4 short arm spines on the side of each segment. One oval tentacle scale. Single tricuspid tooth at the apex of each jaw and two small oval papillae on each side. Disc olive green or dark grey, radial shields a contrasting white, arms often with blotches on green pigment spaced on either side of the dorsal midline. Older animals with faded pigmentation.

Biology

This species reproduces by releasing eggs or sperm in May-June. The resulting larvae are called ophiopleuti, have long calcite spines, can feed on phytoplankton and swim for three months before settlement. Ophiactis resiliens is a suspension feeder; individuals bury their discs in coarse sediments, under rocks, or in rock crevices, with 1-4 arms extending vertically into the current. The arms alter their orientation according to the current flow, and the tube feet are widely spread laterally. Particles of food are caught on the papillate tube feet, less commonly on the arm spines, and are transferred to the mouth in a "collapsing wave" of tube feet. Near the arm base the food is compressed into a bolus that is passed to the mouth. Ingested food consists mainly of diatoms.

Distribution

New Zealand and Tasman Sea, including southern and eastern Australia.

Habitat

Reefs, brown algae, sponge and bryozoan beds, under rocks and on holdfasts of kelp.

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