also: せいこうどうぶつ
sipunculan; peanut worm
A phylum of marine worms; the Japanese term is a direct translation of the scientific name Sipuncula. The cross-reference 星虫 (ほしむし) is a more colloquial name for the same group.
See also: ホシムシ
Sipunculans are small worm-like creatures that live on the ocean floor.
This field guide includes a detailed classification of sipunculans.