This view shows the underside of the colony. The original shell the colony encrusted is to the top right and the expansion which has grown beyond the shell, which covered the hermit crab's carapace, is to the left.
This closeup view shows partly expanded polyps, which are about 0.5 mm diameter. Several of these polyps have more than 8 tentacles. Note also the blunt, short, slightly curved spines arising from the stolon mat between the polyps. A few of the smallest polyps may be dactylozooids.
Hydractinia laevispina growing as an extension to a small gastropod shell inhabited by the hermit crab Labidochirus splendescens. Collected from 60-100 m depth in the San Juan Channel, July 2010. The shell is to the bottom right and the extension which has grown beyond the shell is to the upper left. Total colony width about 2 cm. (Photo by: Dave Cowles )
