Population structure of the sailfin sandfish, Arctoscopus japonicus (Trichodontidae), in the Sea of Japan

• Published in: Ichthyological research Vol. 53; no. 4; pp. 357 - 368
• Main Authors: Shirai, S.M.(Japan Sea National Fisheries Research Inst., Niigata), Kuranaga, R, Sugiyama, H, Higuchi, M
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Nature B.V 01.11.2006
• Subjects: ADN; ARCTOSCOPUS JAPONICUS; DNA; ESTRUCTURA DE LA POBLACION; Genetic diversity; GENETIC POLYMORPHISM; Haplotypes; MAR DEL JAPON; MER DU JAPON; MITOCHONDRIA; MITOCHONDRIE; MITOCONDRIA; POLIMORFISMO GENETICO; POLYMORPHISME GENETIQUE; Population growth; POPULATION STRUCTURE; SEA OF JAPAN; Spawning; STRUCTURE DE LA POPULATION; Trichodontidae; INW, Japan, Honshu, Yamaguchi Prefect; INW, Japan Sea; INW, Japan, Hokkaido; Korea, Rep; INW, Korea, Rep
• ISSN: 1341-8998; 1616-3915
• DOI: 10.1007/s10228-006-0356-0

We analyzed patterns of genetic diversity in the sailfin sandfish (Arctoscopus japonicus), focusing on population subdivisions within the Sea of Japan. We observed 270 specimens from nine sampling sites in 1999-2000, i.e., seven sites in the Sea of Japan and two sites from the Pacific coast of Hokkaido. An additional site (30 specimens) was sampled from eastern Korea in the spawning season of 2004 for comparison. Forty haplotypes, compiled into three haplogroups (A-C), were detected based on the comparison of a 400-bp sequence of the anterior part of the mitochondrial control region. In accordance with previous hypotheses from morphological and molecular analyses, genetic discontinuity between the Sea of Japan and the Pacific coast of Hokkaido was conspicuous. Within the Sea of Japan, eight sampling sites were not genetically uniform, and most of the variations among sites were detected between eastern Korea [the "eastern Korea" (EK) population: distributed from the Korean Peninsula to Mishima, Yamaguchi Prefecture] and the other sites along the coast of Japan [the "western Japan" (WJ) population: from Oki Islands to western Hokkaido] (Φ^sub CT^ =0.096, P=0.0183). The WJ population, having lower genetic variability, showed significant departure from neutrality, indicating influences through a recent population expansion. The period of the expansion can be estimated to have begun on the order of 10^sup 4^ years ago. We consider that the present Japan Sea populations have been formed through the invasion of a small ancestral stock to the Sea of Japan and its population expansion during the last glacial period or later. On the other hand, we failed to detect distinct evidence of a population expansion in the EK population. Haplogroup C, detected in a high frequency in this population, was estimated to have mixed with haplogroup A after rapid differentiations of the latter. Therefore, the EK population, strongly influenced by such a mixture, might possess haplogroup C in a higher frequency and a different haplotype composition from the WJ population.[PUBLICATION ABSTRACT]