The Hard Tube Coco Worm secretes a calcareous tube, approximately 1/2 inch in diameter and 5-8 inches 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 Hard Tube Coco Worm should be well-established and contain a rock and gravel substrate. The Hard Tube Coco Worm requires calcium and the proper alkalinity to grow. It is extremely intolerant of poor water quality and copper-based medications.

In the aquarium it is difficult to maintain, and will need supplements of phytoplankton and liquid organic foods.

Approximate Purchase Size: 4" to 7"