noun
arrowhead crab; halimeda crab
A species of decorator crab (Huenia heraldica) known for its leaf-like appearance. Used in marine biology and diving contexts.
ダイビング中にコノハガニを見つけた。
I found an arrowhead crab while diving.
コノハガニは海藻に擬態する。
The arrowhead crab mimics seaweed.
The name 木の葉蟹 (コノハガニ) literally means 'leaf crab', referring to its leaf-like carapace. The exact derivation is uncertain, but it is a descriptive compound.