Meeting Abstract
Evidence for convergence is often based on human perceptions of overall similarity. In order to overcome this bias, we use geometric morphometrics combined with an analysis of phylogenetic signal to determine if two sympatric species are similar in form due to due convergence or shared evolutionary history. The two species, Enteromius aspilus and E. guirali, are sympatric in the Dja River of Cameroon, are deep-bodied, are very similar in color, and appear to school together. The focal species co-occur with seven other species of Enteromius in the Dja River with the more fusiform shape seen in other small barbs across Africa. Mitochondrial data suggests E. aspilus and E. guirali are not sister taxa, and there is no phylogenetic signal when the phylogeny is overlaid on shape space. The convergence between the two is likely due to a variety of factors including predator avoidance and crypsis in open water, social mimicry to increase the benefit of the selfish herd effect, and increased protection of E. aspilus via Batesian mimicry of E. guirali, which has a protective dorsal spine.
