Is a gonochoric species (Bertin et al. 2002), but the mechanisms of its sex determination are not yet fully understood. No morphologically distinguishable sex chromosome pair has been identified. Both sexes have a karyotype consistings of eight homomorphic chromosome pairs (Salemaa 1979; Valentino et al. 1983; Montalenti and Rocchi 1964).
It has been suggested that sex determination results from combined effect of a set of sex determining genes and a maternally inherited cytoplasmic factor (Vitagliano et al. 1994).