About Thylacodes variabilis (M.G.Hadfield & Kay, 1972)
Thylacodes variabilis is a species of worm snail first formally described in 1972 by M.G. Hadfield and Kay. It has a white-brown shell that is either coiled or partly straight, and can grow up to 14 millimeters in diameter. The shell is frequently overgrown by coralline algae or covered with sand grains. It is the only worm snail species found in Hawaii that lacks an operculum. The body of this snail is polychromatic, with individual coloration ranging from white and beige to brown, yellow, and orange. Like other members of its family, Thylacodes variabilis gets its nutrients by filtering algae and detritus out of the water column. This species lives at depths down to 40 feet, in open habitats including tide pools, shallow wave-swept reef flats, and rocky reefs. Individuals attach their shells to both natural and artificial surfaces, and can be transported on the hulls of vessels and other drifting substrates. Female Thylacodes variabilis brood their offspring in egg capsules that are attached to the inside of their shells.
