Evolution - ECD in Tanzanian killifish David recently published a paper from his PhD on ecological character displacement (ECD) in the Tanzanian killifish from the genus Nothobranchius. Coastal Tanzania is a diversity hotspot for killifishes from that genus. N. melanospilus is a widespread species that sometimes is the only species in a pond or co-occurs with other species, often N. eggersi. He shows that N. melanospilus that co-occur with N. eggersi are much bigger and hence have stronger jaws and feed on harder prey items than when they are alone in a pond. The data satisfies four out of six criteria usually used to test for ECD. His results suggest that competition is the main driver of the observed divergence between the two N. melanospilus populations.