Barnacles and Relatives: Thecostraca

Physical characteristics: Trypetesa lampas (abbreviated T. lampas) does not have a hard carapace. Females reach 0.78 inches (20 millimeters) in length. Their body is clear or yellowish and covered by a large, folded carapace. There is one pair of small cirri near the mouth and three uniramous (YU-neh-RAY-mus), or unbranched, pairs on the thorax. The tiny, bottle-shaped males have antennae and no other appendages. They measure 0.047 inches (1.2 millimeters).

Geographic range: They are found along the shores of the Pacific and Atlantic oceans north of the Equator.

Habitat: Adult females use the mantle and chemicals to bore into the shells of living or dead snails and hermit crabs.

Adult females use the mantle and chemicals to bore into the shells of living or dead snails and hermit crabs. (Illustration by Jonathan Higgins. Reproduced by permission.)

Diet: Females flex their bodies to suck water carrying food particles inside the mantle.

Behavior and reproduction: Both males and females are required for reproduction. Adult males select and attach themselves to females while they are still in the non-feeding larval stage. Nauplius larvae molt four times before reaching the non-feeding larval stage. This stage has simple eyes and six pairs of thoracic limbs. Each simple eye has one lens and is used to find a suitable place to begin burrowing.

Trypetesa lampas and people: This species does not impact people or their activities.

Conservation status: This species is not considered threatened or endangered. ∎