First record of the suborder Colomastigidea (Amphipoda) from Brazilian waters, with description of a new species of Colomastix Grube, 1861.

The suborder Colomastigidea consists essentially of small commensal amphipods and, to the date, no species are known from Brazilian waters. Here, a new species (Colomastix trispinosa sp. nov.

Three new species of Colomastix Grube, 1861 (Amphipoda: Colomastigidea) from Todos-os-Santos Bay, northeastern Brazilian coast, br />with identification keys to Atlantic Ocean species.

Colomastigids are small, commensal marine amphipods distributed worldwide. Here we present descriptions of three new species of Colomastix Grube, 1861 from Todos-os-Santos Bay (Bahia state), and separately identification keys to males and females of all known Colomastix species from the Atlantic Ocean. Males of Colomastix iemanja sp.