Asian shore crab
A small crab commonly found on rocky shores in Japan and East Asia. Scientific name: Hemigrapsus sanguineus.
I found many Asian shore crabs on the rocky shore.
Usually written in katakana as a species name; the kanji form 磯蟹 is rare.
Kanji spelling; rarely used in practice.
Compound of 磯 (iso, 'rocky shore') and 蟹 (kani, 'crab'). The exact derivation is straightforward.