Genetic diversity in the Japanese rosy bitterling, Rhodeus ocellatus kurumeus (Cyprinidae)

Abstract

Comparison of meristic characters (pored lateral line scales, vertebrae, and fin rays), and PCR-RFLP analysis in the D-loop and ND1 regions of mitochondrial DNA were performed to estimate the genetic diversity in local populations of the Japanese rosy bitterling, Rhodeus ocellatus kurumeus. In terms of meristic characters, the Fukuoka population was the largest in both range and variance of the number of pored lateral line scales and vertebrae (abdominal and caudal), and Osaka was the second, whereas the Kagawa population showed the smallest range and variance in these characters. In PCR-RFLP analysis, 11 haplotypes (3 in Fukuoka, 2 in Okayama, 2 in Kagawa, and 4 in Osaka) were observed, and nucleotide sequence divergence (NSD) was approximately two times larger in ND1 (mean, 0.61%) than in D-loop (mean, 0.31%). In the neighbor-joining (NJ) tree, based upon the NSD value in ND1, haplotypes were arranged into four clades, which corresponded to the locality of each haplotype. The Fukuoka population was conspicuously apart from the other populations (mean, 0.90% in NSD), but the remaining three showed a similar genetic distance with each other (mean, 0.48%-0.52% in NSD). In haplotype diversity of mtDNA, half the stations in Osaka and all in Kagawa were monomorphic. Especially, two haplotypes endemic to Kagawa were randomly distributed, irrespective of drainages. Rhodeus o. kurumeus in Fukuoka inhabits small rivers and creeks (open water systems), while that in Kagawa and Osaka lives in small ponds (closed water systems). Taking the information of morphology, mtDNA, and habitat into consideration, the low genetic diversity in Kagawa and Osaka populations of R. o. kurumeus is thought to be mainly the result of the isolation of their habitat.

Genetic diversity in wild and reared populations of the Japanese bitterling Tanakia tanago (Cyprinidae)

“…In such cases, temporal reductions in fish population size are likely to have occurred, with consequent loss of genetic diversity through a bottleneck. Loss of n and k, numbers of fish examined and haplotypes, respectively genetic diversity in the mitochondrial genome has also been reported for Rhodeus ocellatus kurumeus populations isolated in small ponds (Kawamura et al, 2001). Kawamura et al (2001) revealed that such populations in closed water systems showed complete monomorphism, although genetic diversity persisted in those inhabiting open water systems.…”

“…The noncoding control region is generally considered as one of the most variable regions in mitochondrial genomes (Meyer, 1993), although Kawamura et al (2001) reported, by PCR-RFLP analysis, that genetic diversity quantified for the control region was approximately half of that for the NADH subunit 1 region. In the present study, using the cytochrome b gene and the control region sequence data, we tried to evaluate the extent of genetic diversity in wild and reared populations of T. tanago, in addition to annual changes in diversity through captive breeding.…”

Genetic population structure of Japanese bagrid catfishes

“…Recent population decline due to human impact, such as habitat fragmentation, may also cause bottlenecks, as suggested for some endangered cyprinids (Ohnaka et al, 1999;Kawamura et al, 2001). However, it is difficult to explain fixation to a single haplotype throughout disjunct populations, as seen in the bagrid fishes.…”

The genetic structure of endangered indigenous populations of the amago salmon, Oncorhynchus masou ishikawae, in Japan

“…Sequences of haplotype mt1 have been deposited in DDBJ/EMBL/GenBank under Accession nos AB2367315 in D-loop and AB236732 in ND1. For further technical details, including PCR, restriction digest and gel run conditions see Kawamura et al (2001).…”