Texas A&M University - Corpus Christi, United States
Background/Question/Methods
Gobies (Gobioidei) comprise seven families containing over 2000 species of fish distributed throughout most aquatic ecosystems including freshwater streams, brackish seas, and coral reefs playing key roles for the energetics and trophic cycling of these ecosystems. The distribution of each goby family varies from a circumglobal distribution across tropical and temperate regions for the families Eleotridae, Gobiidae, and Oxudercidae, to smaller ranges in Milyeringidae which are restricted to a few local and disjunct distributions. Despite their importance and distribution in many aquatic ecosystems across the globe, a global map of biogeographic regions for gobies is lacking. Using a comprehensive dataset of the global distribution of over 1900 goby species, we define biogeographic regions of gobies using a novel grade of membership model which captures how biotas intergrade, and conducted indicator species analyses to identify key taxa which discriminate the regions.
Results/Conclusions
Using a grade of membership model, we identify 7 biogeographic regions that capture abrupt transitions in regions including the Americas and the coasts of Africa indicating evolutionary mechanisms that kept biotas distinct. We also captured gradual boundaries in the Mediterranean and Indo-Pacific reflecting transition zones where goby lineages admix. Analyses of individual families broadly matched to that of the combined analysis indicating that the findings are not driven by a single species rich clade. We also show that several of the families represented are significant indicators, suggesting that different biogeographic regions have significantly different lineages. Our results will enhance studies of the evolution and diversification of this ecologically important group maintaining aquatic ecosystems.
