Community assembly in annual fishes: Nested patterns, environmental niche and biogeographic history.

The assembly of local communities from regional species pools is shaped by historical aspects of distribution, environmental conditions, and biotic interactions. We studied local community assembly patterns in African annual killifishes of the genus (Cyprinodontiformes), investigating data from 168 communities across the entire range of regionally co-existing species. are small fishes associated with annually desiccating pools. We detected a nested pattern of local communities in one region (Southern Mozambique, with as the core and dominant species), but no nestedness was found in the second region (Central Mozambique, with being the dominant species). A checkerboard pattern of local community assembly was demonstrated in both regions. Multivariate environmental niche modeling revealed moderate differences in environmental niche occupancy between three monophyletic clades that largely co-occurred geographically and greater differences between strictly allopatric species within the clades. Most variation among species was observed along an altitudinal gradient; and were absent from coastal plains, , , and were associated with lower altitude and was intermediate and geographically most widespread species. We discuss implications for ecological and evolutionary research in this taxon.