Seasonal migration in the Pacific giant octopus Enteroctopus dofleini

2015 Fiscal Year Final Research Report

• Project/Area Number: 25450288
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Hokkaido Research Organization
• Principal Investigator: SANO Minoru 地方独立行政法人北海道立総合研究機構, その他部局等, 研究員 (80523539)
• Co-Investigator(Kenkyū-buntansha): Itaya Kazuhiko 北海道立総合研究機構, 釧路水産試験場, 研究員 (70536606) ; Uchida Yasuhito 北海道立総合研究機構, 地質研究所, 研究員 (60465961) ; Koshimizu Kenichi 北海道立総合研究機構, 地質研究所, 研究員 (30636171)
• Co-Investigator(Renkei-kenkyūsha): Miyashita Kazushi 北海道大学, 北方生物圏フィールド科学センター, 教授 (70301877)
• Research Collaborator: Bando Tadao
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ミズダコ / 深浅移動 / バイオロギング / 音響調査 / 宗谷海峡 / 藻場 / 底質

Outline of Final Research Achievements

Seasonal migration characteristics of the North Pacific giant octopus, Enteroctopus dofleini (Wülker, 1910), were investigated in the Soya/La Perouse Strait. We conducted capture-recapture surveys using a temperature logger to infer migration patterns for this species, examined the stomach contents of captured individuals, and identified sessile organisms on the sea bottom by sonar and digital camera observations. In addition, we reared octopuses at several water temperatures in temperature-controlled tanks to examine the relationship between temperature and growth rate. The findings showed that octopuses start migrating to deep areas at water temperatures >15°C. No octopuses were observed in shallow areas at temperatures >= 21°C in the Soya/La Perouse Strait. In autumn, when the water temperatures in shallow areas decreased below 19°C, the octopuses appeared to return to these areas in search of food, remaining there from winter to spring.

Free Research Field

水圏応用科学