noun
eunicid worm (Marphysa sanguinea)
A specific marine worm species. Often used in fishing contexts.
See also: イワムシ
釣り餌としてクロムシを使う。
I use eunicid worms as fishing bait.
noun
lugworm (Arenicola brasiliensis)
Rare term for a specific lugworm species. Usually written in kana.
See also: タマシキゴカイ
クロムシはタマシキゴカイとも呼ばれることがある。
クロムシ is sometimes also called タマシキゴカイ.
noun
black-colored insect (e.g. stag beetles)
Colloquial term for any dark-colored insect, especially beetles. Not a scientific classification.
子供たちがクロムシを捕まえた。
The kids caught a black beetle.
Compound of 黒 (kuro, 'black') + 虫 (mushi, 'insect/worm'). The marine worm senses likely derive from the dark coloration of the organisms.