Abstract
Two populations of Pseudobagrus aurantiacus (Temminck and Schlegel) are discontinuously distributed in Kyushu and the districts from Kanto north.These two geographically isolated populations were analyzed karyologically as well as biochemically.
Distinct differences in the karyotypes were observed between two populations indistinguishable in the morphological characters.The karyotype of the Kyushu population has a diploid number of 48 consisted of 10 metacentrics, 6 submetacentrics and 8 telo-and subtelocentrcs.While, the karyotype of northern population invariably has 56 chromosomes including 12 metacentrics, 6 submetacentrics and 10 telo-and subtelocentrics.
Lactate dehydrogenase was separated into five major components in the respective population.The results of subunit-dissociation and recombination test with salt solution indicated that the five Isozymes are tetramers composed of two subunits encoded in two different loci, A and B.The electrophoretic mobilities of LDH-B isozymes were clearly different between the two populations, the northern population has a markedly fast anodally migrating LDH-B isozyme.Also, esterase of each population is different in the number of components, activity, and mobility.
