First record and molecular characterisation of two Gnathia species (Crustacea, Isopoda, Gnathiidae) from Philippine coral reefs, including a summary of all Central-Indo Pacific Gnathia species.

Due to their unusual life cycle that includes parasitic larval and free living adult stages, gnathiid isopods are typically overlooked in biodiversity surveys, even those that focus on parasites. While the Philippines sits within the region of highest marine biodiversity in the world, the coral triangle, no gnathiid species have been identified or described from that region. Here we present the first records of two gnathiid species collected from the Visayas, central Philippines: Gnathia malaysiensis Müller, 1993, previously described from Malaysia, and G. camuripenis Tanaka, 2004, previously described from southern Japan. This paper provides detailed morphological redescriptions, drawings and scanning electron microscope images as well as the first molecular characterisation of both species, Furthermore, a summary of the Central-Indo Pacific Gnathia species is provided. [Display omitted] • Morphological description of two gnathiid species collected from the central Philippines, along with molecular data, are presented. • Gnathia malaysiensis was previously described from Malaysia and G. camuripenis was previously described from southern Japan. • Although the Philippines is in the highly biodiverse coral triangle, this is the first gnathiid description from this region. • The wide geographic range of G. camuripenis suggests dispersal via large, highly mobile fishes, and/or tropical cyclones. [ABSTRACT FROM AUTHOR]