Assessment of invasions of fishing bait shrimps and their parasite

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K05688
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39060:Conservation of biological resources-related
• Research Institution: Hiroshima University
• Principal Investigator: Saito Hidetoshi 広島大学, 統合生命科学研究科(生), 准教授 (00294546)
• Co-Investigator(Kenkyū-buntansha): 大塚 攻 広島大学, 統合生命科学研究科(生), 教授 (00176934) ; 河合 幸一郎 広島大学, 統合生命科学研究科(生), 教授 (30195028)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 釣り餌動物 / 外来種 / 寄生種

Outline of Final Research Achievements

The main results of this study are as follows. The sequence data of the mitochondrial 16S rRNA region suggested that Palaemon sinensis was introduced through import from China as fishing baits in Japan. Palaemon paucidens was confirmed to be spreading from Lake Biwa to all over Japan. In addition, P. paucidens with the same haplotype as Korean individual was also confirmed in a river flowing into Lake Biwa. The sampling of freshwater shrimps infested by the corallanid ectoparasite Tachaea chinensis showed that mean prevalence was 23.1% for P. paucidens and 6.4% for Neocaridina spp. Ratios of the body length of T. chinensis to the carapace length of the host shrimp were almost constant (0.8-0.9) with the host species and parasite growth. Although infestation by early-life-stage individuals of T. chinensis was observed on both shrimp species, P. paucidens appeared to be the principal host for individuals larger than 6 mm in body length.

Free Research Field

水族生態学

Academic Significance and Societal Importance of the Research Achievements

本研究におけるスジエビ類の遺伝的解析結果は、釣り餌輸入を介した国外外来種としての国内への侵入および国内外来種としての各地への分布拡大を裏付けるデータとなった。また、本研究の標本採集により、チュウゴクスジエビおよびスジエビ韓国産個体をそれぞれ29都府県および8都県で確認した。これらの外来スジエビ類の侵入情報は、滋賀県や神奈川県の要注意外来種リストに登録されるなど、地方自治体の外来種対策に反映されつつある。本研究成果は、招待総説（エブオブ）を含むオープンアクセス論文を通じて、研究者だけでなく一般市民にも情報発信している。