Nakamura Gen, Kato Hidehiro
Laboratory of Cetacean Biology, Department of Ocean Sciences, Tokyo University of Marine Science and Technology Minato-ku, Tokyo, Japan.
J Morphol. 2014 Oct;275(10):1113-21. doi: 10.1002/jmor.20288. Epub 2014 May 5.
We investigated growth-related and sex-related morphological changes in the skulls of 144 North Pacific common minke whales Balaenoptera acutorostrata. Measurement was conducted at 39 points on the skull and mandible to extract individual allometric equations relating the length and zygomatic width of the skull. The results revealed no significant differences in skull morphology by sex except for width of occipital bone. The size relative to the skull of the anatomical parts involved in feeding, such as the rostrum and mandible, increased after birth. In contrast, the sensory organs and the anatomical regions involved in neurological function, such as the orbit, tympanic bullae, and foramen magnum, were fully developed at birth, and their relative size reduced over the course of development. This is the first study to investigate developmental changes in the skull morphology using more than 100 baleen whale specimens, and we believe the results of this study will contribute greatly to multiple areas of baleen whale research, including taxonomy and paleontology.
我们研究了144头北太平洋普通小须鲸（Balaenoptera acutorostrata）头骨与生长和性别相关的形态变化。对头骨和下颌骨的39个点进行了测量，以提取与头骨长度和颧宽相关的个体异速生长方程。结果显示，除枕骨宽度外，头骨形态在性别上无显著差异。出生后，参与进食的解剖部位（如吻部和下颌骨）相对于头骨的尺寸增加。相比之下，感觉器官以及参与神经功能的解剖区域（如眼眶、鼓泡和枕骨大孔）在出生时已完全发育，其相对尺寸在发育过程中减小。这是第一项使用100多头须鲸标本研究头骨形态发育变化的研究，我们相信这项研究的结果将对须鲸研究的多个领域，包括分类学和古生物学，做出巨大贡献。
