Field of work
Twelve species of viviparous halfbeaks of the genus Nomorhamphus (Zenarchopteridae) are endemic to freshwaters of Sulawesi, Indonesia. The anal fins of the males of these species are modified and form a copulatory organ. Characters of this so-called andropodium vary within the genus and are used for species delimitation. The actual function of the structure or its components during the extremely brief copulation remains however unclear. Likewise unclear is the question if traits in the female reproductive apparatus also differ among species. Therefore reproductive structures of males and females of several species are investigated by using micro-CT imaging and 3D-reconstructions.