Multivariate morphometric analysis of Pacific herring, Clupea pallasii (Clupeiformes: Clupeidae) in Sakhalin waters: Investigation of intraspecific differentiation

In the Pacific herring, Clupea pallasii, eight samples of spawning, mature fish (collected in 1978 and 1981) and six samples of immature fish individuals (collected in 1979, 1980 and 1984) were analyzed. Mature fish were analyzed by 24 conventional morphometric characters or morphometric indices. By means of discriminant and factor analyses (principal component mode) the existence of differentiating groupings of vector scores was found that have obvious biological meaning as local Pacific herring stocks. In concordance with former morphobiological and genetic data, current multivariate observations supported the existence in the surveyed area of Sakhalin waters of at least three stocks. One of them is the Sakhalin-Hokkaido local stock of Pacific herring, which in the past provided the bulk of herring catches in the region and showed a distinct and sharper morphometric differentiation as compared with other herring assemblages.