We report here on recent collections of freshwater crabs from Antsiranana Province, northern Madagascar. The specimens belong to three species, one of which is new to science and is described here. This raises the number of species of freshwater crabs found in Madagascar to 17. All are endemic to the island and all belong to the Afrotropical family Potamonautidae Bott, 1970. The new species, Foza manonae sp. nov., is compared to other species in this genus, and an updated key is provided. It is distinguished from the other three congeners by characters of the male first gonopod, sternum, carapace, and cheliped. The conservation status of the Malagasy freshwater crab fauna is summarized and discussed in light of the new material reported on here belonging to two other species, Madagapotamon humberti Bott, 1965 and Foza ambohitra Cumberlidge & Meyer, 2009.
Crustacea, taxonomy, Foza; new species, Madagascar, conservation.