noun
common moon crab
A species of crab (Matuta victor) found in sandy coastal waters. The name is usually written in katakana.
砂浜でキンセンガニを見つけた。
I found a common moon crab on the sandy beach.
The name likely derives from 金線 (golden line) referring to markings on the crab, combined with 蟹 (crab). The exact origin is uncertain.