noun
milky fiddler crab
A species of fiddler crab, Austruca lactea, found in Japan and other parts of East Asia. The name is a biological species name, typically written in katakana.
干潟でハクセンシオマネキを見つけた。
I found a milky fiddler crab on the tidal flat.
The Japanese name is a compound of 白扇 (white fan) and 潮招 (tide-inviting), referring to the crab's white claw and its habit of waving it, which resembles beckoning the tide. The exact derivation is uncertain.