Alternate Title

Biodiversity Patterns of Littoral Tidal River Fishes in the Gulf Coastal Plain Region of Mississippi


Fish biodiversity patterns within littoral habitats of major tidal river systems of coastal Mississippi were examined. The biodiversity of littoral tidal river fishes varied meaningfully on several spatial scales in the Gulf Coastal Plain region of Mississippi. Fish diversity typically appeared higher in littoral channel habitats than in side-pond habitats of tidal river systems. Faunal representation by three core groups of littoral fishes (cyprinids, centrarchids, and fundulids) generally differed between side-pond and channel habitats, as well as among different tidal river systems. Some of the faunal variation among systems reflected biogeographic (east/west) trends, but most of the variation reflected system size-related patterns. Among-site similarity in fish assemblage composition reflected both site proximity and system size. Moreover, the degree of variability in assemblage composition increased with system size. Thus, regional assemblage patterns were generally most discernible on the landscape scale, rather than through historical congruence. This limited regional study of tidal river fish biodiversity improved our biogeographic understanding by revealing the importance of landscape-scale factors such as tidal river size and associated variation in the available species pool. Understanding landscape-scale environmental variation is key to explaining regional fish diversity patterns.