''Grapsus longitarsis'' is a species of decapod crustacean in the family

Grapsidae The Grapsidae are a family of crabs known variously as marsh crabs, shore crabs, or talon crabs. The family has not been confirmed to form a monophyletic group and some taxa may belong in other families. They are found along the shore among rocks ...

, 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 {{Decapoda-stub