Does Scaphanocephalus metacercariae inhibit sex change of parrotfishes?

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06219
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Fisheries Research and Education Agency
• Principal Investigator: SHIMOSE Tamaki 国立研究開発法人水産研究・教育機構, 水産資源研究所(横浜), 主任研究員 (70524792)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: ブダイ科 / スカファノケファルス / 宿主 / 寄生虫 / フエフキダイ科 / ディディモゾイド / 死亡率

Outline of Final Research Achievements

Parasite prevalence of Scaphanocephalus (Platyhelminthes: Trematoda: Heterophyidae) metacercariae on the blue-barred parrotfish (Scarus ghobban) was investigated in Yaeyama Islands, southwestern Japan. Higher prevalences were recorded in the southwestern Iriomote-jima Island and northeastern Ishigaki-jima Island, but lower in the area between these two islands. Condition factor and relative liver weight of the parrotfish were not different regardless of intensity of parasite infection. Influence of the didymozoid (Trematoda: Didymozoidae) parasite infection on the mortality of the longface emperor Lethrinus longirostris was estimated by simple simulation using 117 specimens which aged in previous study. The result suggested that the didymozoid parasite infection increases the mortality of Lethrinus longirostris.

Free Research Field

魚類生態学

Academic Significance and Societal Importance of the Research Achievements

吸虫綱ディディモゾイド属の寄生が宿主の死亡率を上昇させることを、簡単なシミュレーションによって定量的に示すことができた。これまで、自然環境下で寄生虫が宿主に与える影響を定量的に評価した研究は極めて少ないため、本研究の手法や成果が今後の寄生虫研究に活かされることが期待される。また、寄生虫が水産物の価値を減少させるという従来の考えに加え、宿主への影響という視点を今後の寄生虫学に広めることにつながると期待される。