A new species of potamid crab, Isolapotamon seowi (Brachyura, Potamoidea) from Kokol Hill in western Sabah, Malaysia, Borneo

A new species of freshwater crab of the genus Isolapotamon Bott, 1968 (Potamidae) is described from western Sabah in Malaysian Borneo. Isolapotamon seowi new species, is the sixth species of Isolapotamon known from Sabah, and differs from its closest congener, I. buntyae Ng, Low & Clark, 2022, from eastern Borneo, in possessing a relatively lower carapace, a more rugose dorsal carapace surface, the postorbital cristae being sharper and subparallel with the frontal margin, relatively shorter fourth ambulatory legs, and the terminal segment of the male first gonopod is gently curved with the subdistal process slightly longer than the distal projection and angled at 90° to the longitudinal axis.