noun
peanut worm; sipunculid
Any worm of the phylum Sipuncula. A biological term, but also encountered in general contexts such as tide-pool guides.
See also: 星口動物
干潮の岩場でホシムシを見つけた。
I found a peanut worm on the rocks at low tide.
ホシムシは星口動物に分類される。
Peanut worms are classified under Sipuncula.
星口動物 is the formal phylum name Sipuncula, while ホシムシ is the common name for individual worms in that group.
From 星 (hoshi, 'star') + 虫 (mushi, 'worm'), referring to the star-like introvert tentacles of these worms.