Early life history of the Antarctic myctophid in the Antarctic ice edge zone

2019 Fiscal Year Final Research Report

• Project/Area Number: 15H05239
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Ecology/Environment
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: Moteki Masato 東京海洋大学, 学術研究院, 准教授 (50330684)
• Co-Investigator(Kenkyū-buntansha): 高橋 邦夫 国立極地研究所, 研究教育系, 助教 (50413919)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: ハダカイワシ科魚類 / 動物プランクトン / 南大洋生態系 / 魚類の初期生活史

Outline of Final Research Achievements

Early life history of a myctophid fish and other mesopelagic fishes, which were exploited by larger predators, were examined. Food habits of zooplankton eaten by these fishes were also studied to understand food web surrounding these fishes. Early stages of major mesopelagic fishes and a squid were distributed in waters situated between cold water mass from continental shelf side and up-welling of the circumpolar deep water, although depth ranges are slightly different each others. Morphological development and ontogenetic changes in larval and juvenile myctophid were clarified. We firstly discovered that the larval myctophid fed on detritus-like particles composed of diatoms.

Free Research Field

魚類学，南大洋生態学

Academic Significance and Societal Importance of the Research Achievements

ハダカイワシ類は，ナンキョクオキアミと並んで最も重要な分類群の一つである．その初期生活史については，これまでほとんど知られていなかったが，形態，分布，食性など基本的な情報が集積できた．また，夏季には，仔魚がアイスアルジーにはそれほど依存しない食物網に位置していることも分かった．このことは，イベント的に起こる氷縁ブルームなどの植物プランクトンの増殖が彼らの生き残りに影響を及ぼすことを示唆している．南大洋においても見出されている植物プランクトン現存量の長期的な変動は，彼らの生活史に，そして成魚を捕食する大型動物の個体群変動に影響を及ぼす可能性がある．