Project R-13783

Unraveling the molecular mechanisms of diversification: Comparative genomics of the monogeneans infecting the gills of the marine barramundi (Lates calcarifer), at both micro and macro evolutionary levels. (Research)

Biological diversity is unevenly distributed across the tree of life: some clades are highly species-rich and others remarkably species-poor. Despite our growing understanding of the conditions and processes that lead to the formation of new species, we still struggle to identify what hinders diversification. Lates perches (Latidae) are fishes with a unique dichotomous distribution pattern. The euryhaline species of lates perches can be found in the Indo-Pacific region, in rivers, brackish estuaries and marine habitats. Barramundi or Asian seabass (Lates calcarifer), a species of substantial importance for the aquaculture sector, is the most prevalent species of lates perches in this region. On the other hand, African lates perches are found in most freshwater river basins and lakes. Interestingly, while marine barramundi host a variety of monogenean gill parasites, various species of African lates perches from different basins unexpectedly host only a single monogenean species, Dolicirroplectanum lacustre. This contrast in parasite species richness is counterintuitive, as typically, parasite species richness is higher in geographically structured areas with high host diversity. While a population-level approach in the African host-parasite system can provide insights into diversification at the micro-evolutionary (intraspecific) level, the conclusions derived from this approach are not directly applicable at the macro-evolutionary level and are specific to freshwater environments. Moreover, studying both macro- and micro-evolution is crucial to understanding diversification, because these two levels of evolution are interconnected and can provide different insights into the processes that drive diversification (micro) and consequently shape the patterns of biological diversity (macro). Recent advances in the field of genomics have provided new tools for studying evolution in soft-bodied organisms. In this study, we will examine the genomic diversity of the marine barramundi and its much more diverse monogenean parasite community in addition to the species-poor African freshwater monogeneans using a comparative genomics approach.

01 March 2023 - 28 February 2024