Chromosomal evidence for laboratory synthesis of a triploid hybrid between the gynogenetic teleost <i>Poecilia formosa</i> and its host species

Abstract

Cytogenetic analyses were performed on a triploid hybrid individual produced in the laboratory by mating Poecilia formosa , an all‐female gynogenetic diploid species, with a normal male of melanistic ornamental Poecilia sphenops (black molly). Direct chromosome preparations revealed 69 (3n) chromosomes in the somatic complement. This cytogenetic observation in conjunction with the pigmentation phenotype leads us to conclude that occasional failure of sperm exclusion may result in the presence of triploid hybrids even in the natural habitats.