Species diversity of cryophilic marine ostracods; the history clarified by fossil records

• Project/Area Number: 18K06390
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45030:Biodiversity and systematics-related
• Research Institution: Nihon University
• Principal Investigator: OZAWA Hirokazu 日本大学, 生物資源科学部, 准教授 (20632045)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 生物多様性 / 貝形虫 / 分類 / 系統 / 新生代 / 北西太平洋 / 環境変動 / 化石 / 生活史 / 海洋環境変動 / 日本海 / 生物多様性変遷史 / 海洋環境変動史

Outline of Final Research Achievements

This research is studying marine cryophilic ostracods (crustacea) living in and around Japanese Islands. This study is trying to clarify their suitable living conditions for present habitats, the history from their birth to flourishing, places of the birth and flourishing, key factors of environmental changes for their diversifying process, with estimates for the phylogenetic relationship among plural species for two families. Furthermore this research will clarify the primary cryophilic fauna in the northwestern Pacific margin and the history of taxonomic diversity changes. For the last three years, this study obtained the basic data to be able to infer periods of the birth and environmental conditions of their habitats, with the
estimation for phylogenetic relationships based on pore distributional pattern on carapace for one genus of one family. We will represent these data on scientific journals and talks in academic meetings in domestic and international congress near future.

Academic Significance and Societal Importance of the Research Achievements

本研究は北西太平洋縁の新生代の好冷性生物の初期相と、分類学的多様性変遷史の解明を目指して解析を行った。特に400万年前以降は好冷性海生動物群の初期生物相が形成された重要な時期であるが、日本産海洋生物でその時期と前後の生物相変化について、科・属内レベルで種数変遷や種交代、種間の系統関係を古環境変動史も総合して詳しく論じた研究例はほとんど無い。そのためこのテーマについて研究する意義は大きい。また複数の新生代の地層産貝形虫化石群の解析に基づき、古海洋環境と変動史を検討した。これらは、日本列島沿岸で特に環境変動の激しかった、新生代の中新世以降の生物多様性変遷と海洋環境変動を解明する上で重要である。

Research Products

• [Journal Article] 教職課程科目「地学概論Ⅰ」における初歩的な計算問題の実践例と課題 (2021)
  • Author(s): 小沢広和・中井静子・佐藤武宏・中尾有利子
  • Journal Title: 教職課程紀要 Volume: 4 Pages: 91-96
• [Journal Article] 神奈川県藤沢市江の島の地質調査実習における地層と地形の観察―葉山層群と三浦層群の観察の手引き― (2020)
  • Author(s): 小沢広和・中尾有利子・塚脇真二
  • Journal Title: 生物資源科学 Volume: 29 Pages: 9-30
  • NAID: 40022310453
  • Peer Reviewed
• [Journal Article] 鎌倉市稲村ヶ崎の地質調査実習における地層と地形の観察―三浦層群逗子層の観察の手引き― (2019)
  • Author(s): 小沢広和・中尾有利子
  • Journal Title: 生物資源科学 Volume: 28 Pages: 13-26
  • NAID: 40021964070
  • Peer Reviewed
• [Journal Article] Paleoenvironmental analysis from fossil ostracod assemblages of the Middle Pleistocene Naganuma Formation in the Sagami Group, central Japan (2019)
  • Author(s): Ozawa, H. and Tanaka, G.
  • Journal Title: Bulletin of the Geological Survey of Japan Volume: 70 Pages: 5-16
  • NAID: 130007631567
  • Peer Reviewed / Open Access
• [Journal Article] 三浦半島南西部荒崎海岸の地質調査実習における地層と地形の観察―三浦層群三崎層の観察の手引き― (2018)
  • Author(s): 小沢広和・中尾有利子
  • Journal Title: 生物資源科学 Volume: 27 Pages: 13-32
  • NAID: 40021643066
  • Peer Reviewed
• [Presentation] 下総層群木下層（MIS 5e）の貝形虫化石群集から推定される古東京湾の古環境変遷 (2021)
  • Author(s): 原島舞・中澤努・小沢広和・金子稔・石川博行・野村正弘・上松佐知子
  • Organizer: 日本地球惑星科学連合2021年大会（５月発表予定）
• [Presentation] 伊豆外浦湾アマモ場の葉上性貝形虫相（甲殻類）と生活史 (2019)
  • Author(s): 小沢広和・中尾有利子・中井静子・石井勇渡・金子夏美・佐藤大輝・松元一将
  • Organizer: 日本動物分類学会第55回大会
• [Presentation] 多摩川河口における貝形虫類Ishizakiella miurensisの殻サイズの季節変化 (2019)
  • Author(s): 浅野心・上山紗也加・小沢広和・中井静子・中尾有利子
  • Organizer: 2019年日本ベントス学会・日本プランクトン学会合同大会
• [Presentation] 富山県・八尾層群（前～中期中新世）産浅海および漸深海オストラコーダ化石群と産出意義 (2019)
  • Author(s): 小沢広和
  • Organizer: 日本古生物学会第168回例会
• [Presentation] Bathyal ostracod fossils from the Early to Middle Miocene Yatsuo Group in central Japan and their implications for understanding the history of the Japan Sea opening (2018)
  • Author(s): Ozawa, H.
  • Organizer: The Third Asian Ostracod Meeting, Kanazawa (JAPAN)
  • Int'l Joint Research
• [Presentation] Phytal ostracod fauna and its seasonal changes inhabiting eelgrass Zostera at Sotoura Bay of Izu Peninsula, central Japan (2018)
  • Author(s): Ozawa, H., Nakao, Y., Nakai, S., Ishii, H., Kaneko, N., Sato D., Matsumoto, K. and Ito, S.
  • Organizer: The Third Asian Ostracod Meeting, Kanazawa (JAPAN)
  • Int'l Joint Research
• [Presentation] Life cycle of Ishizakiella miurensis deduced from population dynamics (2018)
  • Author(s): Kamiyama. S., Nakao, Y. and Ozawa, H.
  • Organizer: The Third Asian Ostracod Meeting, Kanazawa (JAPAN)
  • Int'l Joint Research