Jan Möhring

Field of work

Within the scope of my master thesis, I studied the functional morphology of endemic ricefish species inhabiting Lake Poso in Central Sulawesi, Indonesia with regard to their trophic differentiation. This geologically ancient lake is inhabited by three different ricefish species of a monophyletic lineage belonging to the genus Oryzias, meaning that more ricefish species occur there sympatrically than in any other place of the world. The three species are characterized by differences in body shape, and appear to inhabit different habitats within the lake. This suggests a potential case of an adaptive “mini-radiation”. To initiate testing this hypothesis, I generated preliminary data on the degree of morphological differentiation between the three species. Using two- and three-dimensional imaging techniques, I deployed geometric morphometrics and modelling approaches of mechanical potentials within the jaw apparatus to demonstrate interspecific differences.