Reproduction experiment on Austropotamobius pallipes complex under controlled conditions: Can hybrids be hatched?

Abstract

The Austropotamobius pallipes complex is formed by the two species A. pallipes and A. italicus, recently defined only on genetic basis, without obvious morphological features for their differentiation. Dealing with this problem, we have conducted a breeding experiment between these two presumed species under controlled conditions, in order to investigate the complex, possible existence of reproductive barriers. Using 80 breeders (56 females controlled and 24 males) collected from populations where their species identity was genetically well established, we performed four series of trials: Fita ×Mpal and Fpal × Mita interspecific mating; Fita × Mita and Fpal × Mpal intraspe- cific mating as a control. We have monitored only the main phases of the reproduction in order to avoid excessive interference for the crayfish. In November 2009 the 91.7% of females having intraspecific mating, as well as the 100% of females having interspecific mating, produced eggs. In June 2010 the eggs from the 36.4% of females having intraspecific mating, and those from the 42.3% of females having interspecific mating did hatch. We emphasize the hatching of hybrids and their vitality.