Incisocalliope aestuarius (Crustacea: Amphipoda: Pleustidae), an old introduced species in the Gironde Estuary (SW France)

The amphipod Incisocalliope aestuarius was recently collected since 2015 in the mesohaline part of the Gironde Estuary (SW France) with a van Veen grab and in the lower intertidal part in oyster bed by hand-picking. A look back at past studies showed that this species was present in this estuary since 1976, whereas the original description of this amphipod comes from Watling and Maurer in 1973, from the East coast of America. The validity of the Incisocalliope genus is herein questioned, and it is proposed to transfer species of the genus Inciscalliope to Parapleustes genus.