noun
black-lip pearl oyster
Scientific/common name for Pinctada margaritifera, a marine bivalve known for producing black pearls.
クロチョウガイは黒真珠を産することで知られている。
The black-lip pearl oyster is known for producing black pearls.
Compound of 黒 (kuro, 'black') + 蝶 (chō, 'butterfly') + 貝 (kai, 'shellfish'), referring to the shell's dark, wing-like appearance. The reading ちょうがい is a standard rendaku form.