Caribbean Amphipoda (Crustacea) of Panama. Part V: parvorder Amphilochidira.

The parvorder Amphilochidira includes 1,152 described species in 24 families. Amphilochidiran amphipods retain many plesiomorphic character states and are thought to represent the ancestral state of amphipods. Many amphipods in this parvorder cling to substrates such as algae or sponges. Nineteen species from four families within the parvorder are documented from Bocas del Toro, Panama, including one new species, Apolochus dragensis sp. nov. Range extensions are documented for eight species, including two species previously documented only from the Pacific Ocean. All species are diagnosed and an identification key to the Amphilochidira amphipods of Panama is provided herein.