Mudskippers are amphibious fishes, presently included in the subfamily Oxudercinae, within the family Gobiidae (gobies). Recent molecular studies do not support this classification, as oxudercine gobies appear to be paraphyletic relative to amblyopine gobies (Gobiidae: Amblyopinae), thus being included in a distinct "Periophthalmus lineage", together with amblyopines. Mudskippers can be defined as oxudercine gobies that are "fully terrestrial for some portion of the daily cycle" (character 24 in Murdy, ****). This would define the species of the genera Boleophthalmus, Periophthalmodon, Periophthalmus, and Scartelaos as "mudskippers". However, field observations of Zappa confluentus suggest that also this monotypic genus should be included in this definition. These genera presently include 32 species. Mudskippers use their pectoral fins and pelvic fins to walk on land They typically live in intertidal habitats, and exhibit unique adaptations to this environment that are not found in most intertidal fishes, which typically survive the retreat of the tide by hiding under wet seaweed or in tide pools.