Ocean Basins and the Biogeography of Freshwater Fishes

Geological evolution of the Indian and Pacific Ocean basins, including the Tethys Sea, is relevant to the evolution and distribution of Indo-Pacific freshwater fishes. Area cladograms derived from phylogenetic analyses of atherinomorph fishes are compared, in part, with those for plant bugs, cicadas and bats. Geologically and biologically composite islands in the Indo-Australian archipelago such as New Guinea, Borneo and Sulawesi, are confirmed. If any lines (such as Wallace's, Weber's and so on) are to be drawn, they should pass through these complex islands, not between them, to mark the closing of the ancient Tethys Sea. Sicydiines are a group of circumtropical, insular and coastal, amphidromous gobies: adults live and breed in freshwater, whereas larvae are transported to the sea where they undergo transformation. Sicydiine genera are restricted to ocean basins. Hypotheses of relationships among ocean basins, as indicated by phylogenetic relationships among sicydiine genera and by other, distantly related, aquatic vertebrates and plants, share components. Implications of oceanic biogeographic regions for continental biotas are outlined using South America as an example. A continent is part of the biogeographic regions of all the oceans it contacts.