抄録
Loaches, Misgurnus anguillicaudatus, collected from Torentsu river, Ibaraki, Japan, were found to comprise two types based on the morphological and genetic traits. Complete substitution of alleles of the two types at the AAT-2* and GPI-1* loci were found, as well as significant differences in allele frequencies at eight other loci. The genetic distance between the two types was 0.4. The belly color was yellowish in type I and grayish in type II, and the average number of precurrent rays was 21.4 (range: 16-25) and 10.5 (range: 7-13), respectively.
The results suggested that the two types should be regarded as a distinct biological species.
