Frequency-dependence of mating success in Poeciliopsis monacha (Pisces, Cyprinodontiformes) reproductive complex, Sonora, Mexico

Abstract

A diversity of all-female fishes of the genus

Variations on maternal-embryonic relationship in two natural and six laboratory made hybrids of Poeciliopsis monacha-lucida (Pisces, Cyprinodontiformes)

“…Ovarian contents of females were analyzed. Eggs bigger then 1.5 mm diameter and presenting yellow and opac colour were classify as mature (Quattro and Weeks, 1991;Lima and Bizerril, 2002). Embryos were classified for three stage of development considering morphological stages of variation (Turner, 1937;Thibault and Schultz, 1978).…”

“…These biotypes depend on the sperm of paternal species to reproduce (Schultz, 1969;Schultz, 1989). Such sexual parasitism implies a strong competition for space, food, and sperm among members of mixed reproductive complexes Schenck and Vrijenhoek, 1989;Weeks et al, 1993;Weeks, 1996;Lima, 1998;Lima and Bizerril, 2002).…”

“…However these reproductive complexes seem to be temporally stable where sexual species and several all-female biotypes that often successfully co-exist even though strong competition for resources (Stenseth et al, 1985;Vrijenhoek et al, 1989;Weeks et al, 1993;Lima and Bizerril, 2002). Reproduction of fishes in the genus Poeciliopsis have been intensively studied to understand how the paradoxical coexistence between sexual and all-female biotypes is possible to identify mechanisms that might sustain a diversity of allfemales (Schultz, 1982;Schultz, 1989;Vrijenhoek, 1984;Vrijenhoek, 1993;Lima and Bizerril, 2002). The laboratory made hybrids produced by Wetherington et al (1987) represent new and unselected strains that have been used to analyze several traits to test model that attempt to explain the source and the mechanisms responsible for the hybrid diversities observed in Mexico.…”

Premeiotic endomitosis and the costs and benefits of asexual reproduction

“…Within the Ambystoma jeffersonianum complex of mole salamanders, the number of eggs produced by asexuals was, on average, only approximately two‐thirds that of sexuals (Uzzell, ). Gynogenetic triploids of the topminnow Poeciliopsis monacha‐lucida have lower size‐corrected fecundity than the diploid sexual parental species P. monacha (Lima & Bizerril, ).…”

“…Similarly, whereas endoduplication may contribute to the lower fecundity of asexual Poeciliopsis monacha‐lucida compared with that of the sexual parental species P. monacha , there is another potential cause that may contribute to these differences. This is the presence in the asexual of the parental P. lucida genome (Lima & Bizerril, ).…”