Fishes that rule the world: circumtropical distributions revisited

Briggs () published the first checklist of circumtropical fishes with 107 species. This work served for a half century as the most comprehensive checklist of globally distributed fishes, but the intervening years witnessed many discoveries, and molecular data have changed the way we evaluate species. Here, we update the list guided by taxonomic revisions, phylogenies, phylogeographic data and DNA barcodes. The resulting list now includes 284 species. The dramatic increase is primarily due to two trends: (i) continued oceanic exploration leading to range revisions and species discoveries and (ii) public databases such as FishBase and the Catalogue of Fishes make range data more accessible. Five species were removed from the list as closer scrutiny revealed multiple taxa, 14 were removed due to updated range information, and 35 more are suspected to be species complexes. The species listed here are mostly pelagic and bathypelagic fishes. Euryhaline, anadromous, catadromous, freshwater, and with few exceptions, reef fishes do not achieve global distributions. The most species-rich family of marine fishes (Gobiidae) is absent. The fishes with the longest pelagic larval stage (Anguillidae) are absent. In contrast, requiem sharks (Carcharhinidae), tunas (Scombridae), jacks (Carangidae), remoras (Echeneidae) and especially lanternfishes (Myctophidae) have multiple representatives. The combined evidence indicates that high mobility as an adult is a key requirement to achieve a global distribution. Many others are members of monotypic genera or families, indicating old lineages that did not diversify. We conclude that global ranges may promote persistence over evolutionary timescales, but also reduce opportunities for speciation.