Influence of Phylogenetic Community Structure on Introduced Fishes in the Southeast United States

A central goal of invasion ecology and management efforts for introduced species is to identify both the communities susceptible to introduction and the likelihood of success of a species’ introduction within a given community. Ecological theory suggests multiple roles for the influence of phylogenetic relatedness and community structure on a community’s invasion potential and the success of introduced species, including a reduction in available niche space in diverse communities or successful invaders occupying unique niches. Although the interplay between phylogenetic community structure/diversity and invasion success has been well studied in plant communities, few studies have examined its role in vertebrate communities, especially fishes. We examined the influence of phylogenetic community structure on invasions in fish communities in the South-Atlantic Gulf region (HUC 03). At the sub-basin (HUC8) scale, there was no relationship between number of introduced species and native species richness or phylogenetic diversity. At the basin (HUC6) scale, there was a significant negative relationship between community phylogenetic diversity and number of introduced fishes, echoing a similar (but non-significant) trend for species richness where more diverse communities had fewer numbers of introduced species. Future analyses will investigate the influence of relatedness of successful and unsuccessful invaders to native fish communities.