〇 Salmon physiology: Homing migration and olfaction

Faculty of Fisheries Sciences, Hokkaido University　KUDO Hideaki

Salmon that are born in the river and grow up in the ocean perform a “homing habit”, returning to the river where they were born in order to leave behind their offspring. This life phenomenon is not only biologically interesting, but also fisheries and propagation projects have been developed to take advantage of this characteristic. In this lecture, I will give an overview of salmon migration, mainly from a physiological perspective, and discuss ongoing research on “olfactory imprinting”, which is strongly related to the identification of the home river during the final stage of homing habit.

河川: river

産卵・受精: spawning and fertilization →ふ化: hatching →浮上: surfacing →稚魚: juvenile

サケ，カラフトマス: chum salmon and pink salmon その他の遡河性サケ属魚類: other anadromous salmonsパー: parr →銀化変態: smoltification →スモルト: smolt

降海回遊: descending migration 母川刷込: mother river imprint 嗅覚: olfaction 各河川固有のアミノ酸組成: amino acid composition specific to each river

海洋: ocean

索餌回遊: foraging migration

成長: growth →性成熟開始: start of sexual maturity 磁気感覚: magnetic sensation →母川回帰: return to mother river →母川想起・識別: mother river recall and identification