2012 Volume 17 Issue 1 Pages 63-71
Acheilognathinae is a subfamily of Cyprinidae that demonstrates a unique reproductive habit in which females lay eggs on the branchiae of fresh water bivalves, including the family Unionidae. Three species of Acheilognathinae -Tanakia limbata, T. lanceolata and Rhodeus ocellatus ocellatus- are distributed in Kagoshima Prefecture. It is noteworthy that the southern limit of the geographical distribution of T. limbata occurs in the northern part of the prefecture. Domestic Acheilognathinae species, including T. limbata, are exposed to the risks of competition and interspecific hybridization with alien species. Little information is available regarding the distribution of Acheilognathinae in Kagoshima Prefecture; therefore, we surveyed the distributions of Acheilognathinae and Unionidae in the area. T. limbata, R. o. ocellatus and T. lanceolata were collected during surveys on 16 rivers. Fishes suspected as hybrids of T. limbata and R. o. ocellatus were also found. Live individuals or empty shells of three Unionidae species, Pronodularia japanensis, Inversiunio reinianus yanagawensis and Anodonta woodiana, were collected. Acheilognathinae seemed to select particular Unionidae species; however, the occurrence of suspected hybrids suggests that this selectivity may be lost under specific conditions.