Ecological roles of large-sized jellyfish in symbiosis

2015 Fiscal Year Final Research Report

• Project/Area Number: 25304031
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 海外学術
• Research Field: Aquatic bioproduction science
• Research Institution: Hiroshima University
• Principal Investigator: Ohtsuka Susumu 広島大学, 生物圏科学研究科, 教授 (00176934)
• Co-Investigator(Kenkyū-buntansha): NAGAI HIROSHI 東京海洋大学, 海洋科学技術研究科, 教授 (50291026) ; OHKOUCHI NAOHIKO 国立研究開発法人海洋研究開発機能, 生物地球科学研究分野, 分野長 (00281832) ; OGAWA NANAKO 国立研究開発法人海洋研究開発機能, 生物地球科学研究分野, 主任技術研究員 (80359174)
• Co-Investigator(Renkei-kenkyūsha): MIYAKE HIROSHI 北里大学, 海洋生命科学部, 准教授 (00373465) ; NISHIKAWA JUN 東海大学, 海洋学部, 教授 (10282732)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 国際共同研究 / 水産学 / クラゲ類 / 共生 / 稚魚 / クモヒトデ類 / 吸虫類 / クラゲ漁業

Outline of Final Research Achievements

In Asian waters, large-sized jellyfish harbor a wide variety of symbionts such as fish larvae, swimming crabs, trematode larvae, brittle stars and shrimps, some of which are commercially important as sea foods. Jellyfish are obligatory hosts for young stages of some mackerels, trematodes and brittle stars. Metacercariae of 3 species of trematodes utilize scyphomedusae as the second intermediate and/or paratenic hosts, while medusivorous fish such as butterfish are final hosts. The composition of symbiotic communities is influenced by the occurrence, size, swimming speed and toxicity of hosts. Jellyfish fisheries carried out in Southeast Asia seem to greatly influence these symbionts. For example, in Thailand, about 160 million individuals of symbiotic brittle stars are estimated to be annually eliminated by fisheries at maximum. Therefore, the fisheries most likely make a great impact on not only planktonic but also benthic communities.

Free Research Field

海洋プランクトン学