HYBRIDIZATION EXPERIMENTS IN RHODEINE FISHES (CYPRINIDAE, TELEOSTEI): THE INTERGENERIC HYBRIDS OF ACHEILOGNATHUS LANCEOLATA ♂ × ACANTHORHODEUS ATREMIUS ♀ AND TANAKIA TANAGO ♂ × ACHEILOGNATHUS RHOMBEA ♀

In order to study the phylogenetic relations between rhodeine species a number of interspecific and intergeneric crossings have been performed. This communication deals with the intergeneric hybrids obtained from the combinations Acheilognathus lanceolata ♂ × Acanthorhodeus atremius ♀ and Tanakia tanago ♂ × Acheilognathus rhombea ♀.From the first combination adult hybrids have been obtained which were intermediate between both parental species and showed a male phenotype. The second combination produced larvae, but a deficient yolk supply prevented them from reaching the free-swimming stage.Experimental evidence is presented for the occurrence of a dominant genetic factor in A. rhombea males, which controls the duration of embryonic development in this and other bitterling species.