Meeting Abstract
Correct species identification is essential to assess biodiversity and species richness in ecosystems threatened by environmental changes such as in the warming Antarctic waters. Recent findings suggest we have just begun to appreciate how complex is the notothenioid radiation and species identification. This study aims to expand our knowledge about the two notothenioid genera Chionodraco and Lepidonotothen. By means of population genetics and otolith shape analyses, we intend to ascertain whether and how extensive is the interspecific gene exchange within genera, how many species they include and what species are taking part in the system. By means of a Lagrangian modelling approach, we want to test hypothesis about possible routes of dispersal of Antarctic fish species and what is the geographic scale of the interspecific exchange. So far, genetic results indicate that hybridization occurs among species within the two genera although not extensive enough to prevent species diversification, while otolith morphology analysis enables the approximate separation of species-specific clusters. Oceanographic patterns suggest alternative routes of dispersal that could support the transport of larval stages. Ecological barriers to interspecific reproduction could constrain the impact of hybridization in sympatric Chionodraco and Lepidonotothen species. This study is expected to contribute an overall picture of the two genera in terms of distribution and genetic structure, providing tools and protocols to assist the identification of species and hybrids as a valuable resource also for other Antarctic notothenioid species.
