Inventory and new records of benthic amphipods from macrophytes and fine sand communities of the Bizerte lagoon (Tunisia, SW Mediterranean Sea)

Shallow water benthic communities from the Bizerte lagoon (northern Tunisia) were investigated at 33 stations sampled in April and July of 2016 and 2017. A total of 18 amphipod species were recorded among which two new species were recorded: one for Tunisian coasts ( Jassa marmorata ) and a second one for the Mediterranean Sea ( Serejohyale spinidactylus ). In addition, and compared to previous studies, nine amphipod species were collected for the first time in this lagoon. Amphipod assemblages were numerically dominated by the families Melitidae (28%), Caprellidae (14.5%) and Ampithoidae (11.7%). Three species: Cymadusa filosa, Dexamine spinosa and Elasmopus rapax were numerically dominant. According to their biogeography, most of the recorded amphipod species (11–18) showed an Atlantic–Mediterranean distribution, whereas four were cosmopolitan and three lessepsian Indo-Pacific migrants, but no species were Mediterranean endemic. Specimens of both Jassa marmorata and Serejohyale spinidactylus are illustrated and described.