CONFIRMATION OF GYNOGENESIS IN PHOXINUS-EOS-NEOGAEUS (PISCES, CYPRINIDAE)

We have previously reported that the all-female species Phoxinus eos-n eogaeus is perpetuated at Norton Pool, New Hampshire, by clonal reprod uction. Genetically identical diploid eos-neogaeus ova develop into di ploid offspring if congeneric sperm stimulates development, and into t riploid or diploid-triploid mosaic offspring if syngamy occurs. Some i ndividuals produce both genetically identical and unique diploid ova, resulting in clonal and nonclonal offspring. In a third, very differen t type of gametogenesis, other females produce haploid eos ova that yi eld diploid ''P, eos'' offspring if fertilized by P, eos sperm. In thi s study we confirmed all three types of gametogenesis by mating two fe males of P. eos-neogaeus to a male of a related species, P. oreas, who se distinctive contribution to the offspring was revealed through morp hology, genome size, and tissue graft analysis. In a second set of exp eriments we show that the same clone has existed at Norton Pool for 11 years. Lastly, we show that gynogenetic reproduction is not restricte d to Norton Pool, but that hybrids from Algonquin Park, Ontario, also reproduce clonally.