I’m thrilled to share my latest research about the fascinating African Great Lakes region, a location known to many as a treasure trove for studying speciation. Decades of research have revealed the remarkable story of the speciation of the famous cichlid fishes in the African Great Lakes. More than 200 species of cichlids are endemic to Lake Tanganyika. One of the species flocks in the lake has migrated to the neighboring Lake Malawi and Lake Victora, where they again speciated. Studying these speciation events, called adaptive radiations, has taught us much about how new species originate. However, it’s not just about the cichlids. Many organisms have diversified in these lakes, such as Ostracodspa, various Molluscs such as Snails and Mussels, and even Monogenea flatworms that parasitize the gills of cichlids.
In my recent paper, I described something spectacular - a clade of 16 Macrostomum flatworms we found in Lake Tanganyika and nested within it one species from Lake Malawi. Molecular studies suggest that these flatworms may have undergone a swift speciation, likely because they adapted to the diverse habitats the lake has to offer. But the surprises don’t stop there. The sperm morphology of these flatworms differs quite significantly from those discovered outside of Lake Tanganyika and Lake Malawi. The observed changes in sperm morphology suggest that they are an evolutionary novelty that could be important for sexual selection and sexual conflict.
One of the highlights of this research journey has been the chance to describe five new Macrostomum species. I describe Macrostomum gracilistylum found in Lake Malawi and four from Lake Tanganyika, including Macrostomum crassum, Macrostomum pellitum, Macrostomum longispermatum, and Macrostomum schäreri. The big question remains: Did these flatworms truly radiate in Lake Tanganyika and then migrate to Lake Malawi? Is this an adaptive radiation tale waiting to be fully unraveled? It looks promising, but there’s much more to uncover. Certainly, the African Great Lakes are an excellent place to further our understanding of flatworm diversity and speciation. Stay tuned for more discoveries!
Dive into the details in the article here