Integrating genetics and morphometrics in species conservation-A case study on the stone crayfish, Austropotamobius torrentium

The stone crayfish, Austropotamobius torrentium, is a freshwater crayfish species native to Central and Southeast Europe. Due to various, mostly anthropogenic factors the species is facing a dramatic decline in many European countries. In order to plan and implement protection measures, it is essential to collect extensive data on the species, including biological aspects and the major threats. Therefore, in the frame of a species conservation program in western Austria, we assessed the genetic relationship of the local endangered stone crayfish populations to populations in eastern Switzerland and southern Germany as well as their genetic diversity using mitochondrial and nuclear DNA markers. Population differentiation was measured applying both genetic and morphometric tools in order to estimate the suitability of potential donor populations for future restocking and reintroduction measures. The results showed a high degree of genetic homogeneity at the lineage level in the alpine stretch of the Rhine valley. Despite a rather low genetic diversity, nuclear markers provided signs of genetic divergence among populations even at a local scale. Due to the inconsistencies found between genetic and morphometric differentiation patterns, we highlight the importance of integrating both tools for the identification of suitable crayfish stocking material.