Verification of hypotheses that Teuthida squids gather to artificial light for feeding

• Project/Area Number: 25450277
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Nagasaki University
• Principal Investigator: MATSUSHITA Yoshiki 長崎大学, 水産・環境科学総合研究科(水産), 教授 (30372072)
• Co-Investigator(Kenkyū-buntansha): SUGA Koushirou 長崎大学, 水産・環境科学総合研究科(水産), 准教授 (60569185) ; SHIMIZU Ken-ichi 長崎大学, 水産・環境科学総合研究科(水産), 准教授 (20533946)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 光 / イカ類 / 蝟集 / 餌生物 / 胃内容物 / DNA / 集群

Outline of Final Research Achievements

We verified the hypothesis that squid attract the artificial light source to feed organisms, in addition to a conventional hypothesis due to photo taxis. For this purpose, we conducted a field survey in Tsushima Strait. We sampled zoo plankton that distributed around the light source by net tows with time intervals. We also sampled 251 individuals of swordtip squid Loligo edulis by jigging and observed those stomach contents. Copepod and amphipod were most sampled but they were not observed in stomach contents. From DNA analysis of stomach contents, we identified they ate squids, sardines and some other fish species. We also conducted DNA analysis for squid captured by bottom trawl fishing and found that squid mostly ate demersal species in this case. We consider that squid showed an opportunistic feeding behavior that they ate most accessible organisms (e.g. fish attracted around the light).

Research Products

• [Journal Article] いか釣り漁業の合理化について―漁業の現場から― (2016)
  • Author(s): 串崎 康文，松下吉樹
  • Journal Title: 水産工学 Volume: 52 Pages: 227-231
  • Peer Reviewed
• [Journal Article] 小型イカ釣り漁船のエネルギー収支 (2016)
  • Author(s): 松下吉樹
  • Journal Title: 水産工学 Volume: 52 Pages: 189-195
  • NAID: 130005261240
  • Peer Reviewed
• [Journal Article] The effect of lunar cycle, tidal condition and wind direction on the catches and profitability of Japanese common squid Todarodes pacificus jigging and trap-net fishing (2014)
  • Author(s): Daisaku Masud; Shuya Kai; Naotoshi Yamamoto; Yoshiki Matsushita; Petri Suuronen
  • Journal Title: Fisheries Science Volume: 80 Issue: 6 Pages: 1145-1157
  • DOI: 10.1007/s12562-014-0799-6
  • NAID: 120006986842
  • Peer Reviewed
• [Presentation] 漁業技術としての光 (2016)
  • Author(s): 松下吉樹
  • Organizer: 照明学会全国大会光放射応用分科会シンポジウム
  • Place of Presentation: 日本大学理工学部駿河台キャンパス（東京）
  • Year and Date: 2016-08-31
  • Invited
• [Presentation] イカ釣り漁業のエネルギー収支 (2015)
  • Author(s): 松下吉樹
  • Organizer: 平成27年度日本水産工学会春季シンポジウム
  • Place of Presentation: 長崎大学（長崎市）
  • Year and Date: 2015-05-31
• [Presentation] Application of the low-power underwater light to a large scale fish-trap fishery 2．Sonar observation and tagging experiment (2014)
  • Author(s): Daisaku MASUDA, Masahiro MAEDA, Shuya KAI, Kei-ichi FURUKAWA, Yoshiki MATSUSHITA
  • Organizer: FAO-ICES WGFTFB
  • Place of Presentation: 米国, New Bedford市
  • Year and Date: 2014-05-05 – 2014-05-09
• [Presentation] 近接して集魚灯を点灯する漁船間の水中の光量子束密度分布の変化 (2014)
  • Author(s): 松下吉樹・眞角聡・清水健一・舛田大作・水田浩二・古原和明
  • Organizer: 平成26年度日本水産工学会学術講演会
  • Place of Presentation: 銚子市商工会館（千葉県銚子市）