Description of new species of algal-boring Limnoria (Crustacea, Isopoda, Limnoriidae) from Japan and redescription of Limnoria segnoides Menzies, 1957 and L. nagatai Nunomura, 2012

Abstract

Previous research on the mitochondrial COI gene sequences of several populations of Limnoria nagatai Nunomura suggested a cryptic species from the Sea of Japan. A new species of algal-boring limnoriid is here described. Limnoria furca sp. nov. was collected from the holdfasts of Eisenia bicyclis on the Oki Islands and the Sea of Japan coast of Honshu and Kyushu Islands, Japan. L. furca sp. nov. is diagnosed morphologically by lacking a mandibular palp, faint subparallel carinae on the pleotelson, faint Y-shaped carinae on pereonite 5, the bifid lacinia mobilis of right mandible and the shapes of the secondary unguis on the pereopods. Similar species, L. segnoides Menzies, 1957 and L. nagatai Nunomura, 2012, are redescribed on the basis of the holotypes.