OLE Seehausen didn’t expect to find much when he dropped his trawling net into Lake Victoria in 1991. The fish he was studying, called cichlids, had been disappearing from the East African lake for years. So he was astounded when he hauled in dozens of them. Close inspection of their coloration and shapes revealed five distinct species. The graduate student couldn’t wait to deliver the news to his supervisor, Frans Witte, at Leiden University in the Netherlands. “The quality of the phone line was so horrible that I wasn’t sure he had understood that we had caught cichlids offshore again,” he recalls…

This article first appeared in Nature on 8 July 2010. To continue reading click here.