Virtual Posters

A taxon group of minke whale (Balaenoptera acutorostrata) distributes in all oceans through polar, temperate and tropical waters in both Hemispheres. Within the group three different morphological types are known from North Atlantic, North Pacific and from southern hemisphere known as dwarf form. Recently North Atlantic and North Pacific minke whales are separated at a level of sub species as being B. a. acutorostrata and B. a. scammoni for respectively, but dwarf type have not been well specified its morphological feature. Osteological feature is one of the most important categorical traits, but few studies have done on the minke whale taxon group. Thus we tried to analyze the morphological and morphometric differences between North Pacific, North Atlantic minke whales and dwarf form. We analyzed the proportion of 54 measurement points on the skull to the skull length and morphological characters, based on 115 North Pacific minke whales collected from the Second Phase of Japanese Whale Research Program under special permit in the western North Pacific (JARPN II), 8 dwarf types collected from the Japanese Whale Research Program under special permit in the Antarctic (JARPA) as well as published morphometric data on 11 North Atlantic minke whales. Through the analyses we found several important osteological features such as differences in shape of the nasal and the existence of interparietal. However, to clarify the taxonomical status among the minke whale taxon group we need further osteological studies using the North Atlantic minke whale samples.