Comparative functional anatomy of hindlimb muscles and bones with referenceto aquatic adaptation of the sea otter

Journal of Veterinary Medical Science

Kent MORI³  Sung-Yong HAN⁵  Daisuke KOYABU⁴  Junpei KIMURA¹  Hideki ENDO⁴  Satoshi SUZUKI² 

[1] Department of Anatomy and Cell Biology, College of Veterinary Medicine, Seoul National University, Seoul 151�?742, Korea;Fukui City Museum of Natural History, Fukui 918�?8006, Japan;Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113�?0033, Japan;The University Museum, The University of Tokyo, Tokyo 113�?0033, Japan;Korean Otter Research Center, Hwacheon-gun, Gangwon-do 209�?821, Korea

关键词: hindlimb;    muscle;    mustelidae;    sea otter;    swimming locomotion;   

DOI  :  10.1292/jvms.14-0534

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(40)Cited-By(1)Supplementary materials(1)Although the sea otter (Enhydra lutris) is a complete aquaticspecies, spending its entire life in the ocean, it has been considered morphologically tobe a semi-aquatic animal. This study aimed to clarify the unique hindlimb morphology andfunctional adaptations of E. lutris in comparison to other Mustelidaespecies. We compared muscle mass and bone measurements of five Mustelidae species: the seaotter, Eurasian river otter (Lutra lutra), American mink(Neovison vison), Japanese weasel (Mustela itatsi) andSiberian weasel (M. sibirica). In comparison with the other 4 species,E. lutris possessed significantly larger gluteus, popliteus andperoneus muscles, but smaller adductor and ischiopubic muscles. The popliteus muscle mayact as a medial rotator of the crus, and the peroneus muscle may act as an abductor of thefifth toe and/or the pronator of the foot. The bundles of the gluteus superficialis muscleof E. lutris were fused with those of the tensor fasciae latae muscle andgluteofemoralis muscles, and they may play a role in femur abduction. These resultssuggest that E. lutris uses the abducted femur, medially rotated crus,eversion of the ankle and abducted fifth digit or extended interdigital web as a powerfulpropulsion generator. Therefore, we conclude that E. lutris is a completeaquatic animal, possessing differences in the proportions of the hindlimb muscles comparedwith those in other semi-aquatic and terrestrial mustelids.

【 授权许可】

Unknown