Coco Worm, Protula bispiralis

The Coco Worm has a crown that can be white, yellow, orange, pink, or red. The radioles may be banded or patterned. Younger Coco Worms have bi-lobed crowns, while the crowns of older individuals are spiraled. The Coco Worm secretes a calcareous tube, approximately 1.5cm in diameter and 12-20cm long, to house its vulnerable worm body. When disturbed, it can quickly retract its crown and close its operculum to shut the top of its tube. It usually anchors its tube in a crevice of the rocky reef or in the gravel along current-swept reef slopes. It uses the radioles to filter out floating plankton.

The aquarium for the Coco Worm should be well-established and contain a rock and gravel substrate. The Coco Worm requires calcium and a stable alkalinity to grow. Due to the increased level of care required for this particular species it will require supplements of phytoplankton and liquid organic foods.