ZOOGEOGRAPHY OF THE SHOREFISH FAUNA OF CLIPPERTON ATOLL

One hundred and fifteen species of fishes (14 oceanic, plus 101 shore and nearshore species) are known from Clipperton Island, a small, remo te coral atoll in the tropical eastern Pacific (TEP). This fish fauna includes only similar to 14% of the region's shallow-water species, an d also is depauperate relative to the fish faunas of other isolated tr opical islands. The island's isolation, small size, reduced habitat di versity, and oceanic environment contribute to this paucity of species . Fifty-two species at Clipperton can be identified as TEP; these incl ude 37 widespread species, six species shared only with the Revillagig edo Islands [the nearest (950 km) offshore shoals], and eight endemic to Clipperton. Endemics species apparently have a mix of west and east Pacific origins. Sixty-three species are transpacific; they include t hree new records (of Naso surgeonfishes) that may be vagrants recruite d > 4,000 km from Oceania. Clipperton is situated at the juncture betw een the TEP and Oceania. Its fish fauna contains about equal numbers o f TEP and transpacific species. This faunal structure reflects the rel ative influence of surface currents from Oceania and the TEP. Although most of Clipperton's transpacific shorefishes are widespread in easte rn Oceania, the Clipperton fauna has specific affinities to the fauna of the Line Islands, which are located within the main eastbound curre nt from Oceania. Clipperton may therefore be a major stepping stone fo r dispersal between Oceania and the remainder of the TEP. About 50% of the non-oceanic, tropical transpacific fishes occur there, and at lea st 75% of those species apparently have resident populations at the is land.