Status of the Catalan chub Squalius laietanus (Actinopterygii, Cyprinidae) in France: input from morphological and molecular data

Two species of chubs in French drainages: the common chub S. cephalus and the Catalan chub S. laietanus restricted to Oriental Pyrenees (South of France). Morphological and molecular characters distinguishing the two species have been described on Spanish specimens, but not tested on French samples. 32 sites were sampled throughout the French water system, yielding 155 specimens of which 60 were sequenced for two molecular markers COI and rhodopsin. Two divergent haplotype clusters for COI are found, and indicate the presence of S. laietanus in France (from Massane to Agly basins). In some sites, both species are sympatric. In some cases, molecular results partially disagree with morphological data, suggesting possible hybridizations between the two. This might threaten Catalan chub in France, and its red list status should be re-evaluated in order to undertake conservation measures.