Stiphodon mele n. sp., a new species of freshwater goby from Vanuatu and New Caledonia (Teleostei, Gobiidae, Sicydiinae), and comments about amphidromy and regional dispersion

Stiphodon mele n. sp. is described on the basis of material collected from Vanuatu and New Caledonia. It is distinguished from all other congeners in having 9 segmented rays in the second dorsal fin, usually 13 pectoral rays, 36-41 fine tricuspid premaxillary teeth, 2 small symphyseal teeth in female vs. 2-4 stout teeth in males, predorsal scales absent, and low number of scales in transverse back (3-7) and lateral series (14-21). This new species spawns in freshwater, the free embryos drift downstream to the sea where they undergo a planktonic phase, before returning to the rivers to grow and reproduce: it is an amphidromous species. As many other Sicydiinae, Stiphodon mele n. sp., is endemic to Vanuatu and New Caledonia. Numerous factors occur to control the dispersion of the amphidromous species. It is necessary to consider all of these factors to explain the existence of many endemic species and the broad or small distribution of the species in the Indo-Pacific area. The management and the conservation of Stiphodon mele n. sp. have to be necessarily regional.