Scholarlink

<p>Freshwater mussels (Unionidae) depend on specific fish hosts to complete their life cycle. Glochidia, their parasitic larvae, must attach to the gills or fins of suitable fish species to metamorphose. However, non-host fish may intercept glochidia, reducing larval availability for competent hosts—a phenomenon known as the dilution effect. We investigated this mechanism in a natural population of the endangered mussel <i>Unio crassus</i>, focusing on the interaction between the dominating host <i>Phoxinus phoxinus</i> and the non-host <i>Gobio gobio</i>. Field surveys across three separate reaches of the Warkocz River (2015–2016) and a controlled infestation experiment demonstrated that <i>G. gobio</i> removes a substantial proportion of glochidia without supporting their metamorphosis. Co-occurrence analysis showed a negative relation between infestation levels of <i>G. gobio</i> vs. <i>P. phoxinus</i>, with a significant interaction modulated by <i>U. crassus</i> density. At low mussel densities, the impact of <i>G. gobio</i> on parasitic success was strongest. <i>Gobio gobio</i> was recorded at 90% of the known <i>U. crassus</i> localities in Poland, and in all of these sites it formed a dominant component of the fish assemblage. Our findings provide direct evidence of a context-dependent dilution effect and highlight the importance of fish community composition and behaviour in conservation of unionid mussels. The presence of non-host fish in habitats with low mussel abundance may undermine recruitment and increase extinction risk in fragmented populations.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Evidence for dilution effect by Gobio gobio, a dead-end host in the Unio crassus–Cyprinidae coevolutionary system

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年12月19日

查看全文
  • Jacek Dołęga,
  • Tadeusz A. Zając,
  • Adam Ćmiel,
  • Anna Lipińska,
  • Krzysztof Tatoj,
  • Katarzyna Zając

摘要

Freshwater mussels (Unionidae) depend on specific fish hosts to complete their life cycle. Glochidia, their parasitic larvae, must attach to the gills or fins of suitable fish species to metamorphose. However, non-host fish may intercept glochidia, reducing larval availability for competent hosts—a phenomenon known as the dilution effect. We investigated this mechanism in a natural population of the endangered mussel Unio crassus, focusing on the interaction between the dominating host Phoxinus phoxinus and the non-host Gobio gobio. Field surveys across three separate reaches of the Warkocz River (2015–2016) and a controlled infestation experiment demonstrated that G. gobio removes a substantial proportion of glochidia without supporting their metamorphosis. Co-occurrence analysis showed a negative relation between infestation levels of G. gobio vs. P. phoxinus, with a significant interaction modulated by U. crassus density. At low mussel densities, the impact of G. gobio on parasitic success was strongest. Gobio gobio was recorded at 90% of the known U. crassus localities in Poland, and in all of these sites it formed a dominant component of the fish assemblage. Our findings provide direct evidence of a context-dependent dilution effect and highlight the importance of fish community composition and behaviour in conservation of unionid mussels. The presence of non-host fish in habitats with low mussel abundance may undermine recruitment and increase extinction risk in fragmented populations.