Phylogenetic relationships among Mediterranean sandhoppers

The present study examines phylogenetic relationships among Mediterranean sandhoppers. Particular attention is given to the Talorchestia group which presents serious systematic problems. Mitochondrial DNA investigations show that the Mediterranean species are clearly separate from Talorchestia martensii, the species chosen as outgroup, because it certainly belongs to the genus Talorchestia sensu Morino and Miyamoto. ‘Talorchestia’ deshayesii appears to be nearer to Talitrus saltator than to the other taxa considered (‘Talorchestia’ brito, ‘Talorchestia’ ugolinii and ‘Talorchestia’ pelecaniformis). Our results show that the Mediterranean ‘Talorchestia’ complex should be divided into three genera, none of which corresponds to the genus Talorchestia sensu stricto. For this purpose, one of us (S. Ruffo) provides preliminary descriptions of two new genera in the Appendix: Deshayesorchestia and Sardorchestia. Finally, our biomolecular method, tested on four populations of Talitrus saltator, is sufficiently sensitive to evaluate genetic affinities among conspecific populations of sandhoppers.