open access

https://hdl.handle.net/2115/70887

Comparative anatomy of the dorsal hump in mature Pacific salmon

英語

water content

2017-07

John Wiley & Sons

Journal of morphology

278(7)

948-959

Mature male Pacific salmon (Genus Oncorhynchus) demonstrate prominent morphological changes, such as the development of a dorsal hump. The degree of dorsal hump formation depends on the species in Pacific salmon. It is generally accepted that mature males of sockeye (O. nerka) and pink (O. gorbuscha) salmon develop most pronounced dorsal humps. The internal structure of the dorsal hump in pink salmon has been confirmed in detail. In this study, the dorsal hump morphologies were analyzed in four Pacific salmon species inhabiting Japan, masu (O. masou), sockeye, chum (O. keta), and pink salmon. The internal structure of the dorsal humps also depended on the species; sockeye and pink salmon showed conspicuous development of connective tissue and growth of bone tissues in the dorsal tissues. Masu and chum salmon exhibited less-pronounced increases in connective tissues and bone growth. Hyaluronic acid was clearly detected in dorsal hump connective tissue by histochemistry, except for in masu salmon. The lipid content in dorsal hump connective tissue was richer in masu and chum salmon than in sockeye and pink salmon. These results revealed that the patterns of dorsal hump formation differed among species, and especially sockeye and pink salmon develop pronounced dorsal humps through both increases in the amount of connective tissue and the growth of bone tissues. In contrast, masu and chum salmon develop their dorsal humps by the growth of bone tissues, rather than the development of connective tissue.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: Susuki K, Ban M, Ichimura M, Kudo H. Comparative anatomy of the dorsal hump in mature Pacific salmon. Journal of Morphology. 2017;278:948–959, which has been published in final form at 10.1002/jmor.20687. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

0362-2525

1097-4687

AA0070290X