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

2015 Fiscal Year Final Research Report

• 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
• Keywords: 光 / イカ類 / 蝟集 / 餌生物 / 胃内容物 / DNA

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).

Free Research Field

漁業生産工学