Grapsus longitarsis
Grapsus longitarsis is a species of decapod crustacean in the family Grapsidae, native to the Indo-Pacific. It was first described by James Dwight Dana in 1851, from a specimen found in the Tuamotu Archipeligo, French Polynesia. The basis for the decision of synonymy is Banerjee (1960). G. longitarsis is a tropical, benthic species living at depths ranging from 0–5 m in the intertidal zone. Precopulatory courtship (via smell and touch) is common and the sperm transfer is usually indirect. References 

Crustaceans described in 1825
Grapsidae