School of Biological and Chemical Sciences, Queen Mary University of London, London, UK.
Department of Life Sciences, Imperial College London, London, UK.
Parasitology. 2022 Aug;149(9):1164-1172. doi: 10.1017/S0031182022000531. Epub 2022 May 16.
How parasites alter host feeding ecology remains elusive in natural populations. A powerful approach to investigate the link between infection and feeding ecology is quantifying unique and shared responses to parasite infection in related host species within a common environment. Here, 9 pairs of sympatric populations of the three-spined and nine-spined stickleback fishes were sampled across a range of freshwater and brackish habitats to investigate how parasites alter host feeding ecology: (i) biotic and abiotic determinants of parasite community composition, and (ii) to what extent parasite infection correlates with trophic niche specialization of the 2 species, using stable isotope analyses (15N and 13C). It was determined that parasite community composition and host parasite load varied among sites and species and were correlated with dissolved oxygen. It was also observed that the digenean sp.'s abundance, a common directly infecting parasite with a complex life cycle, correlated with host C in a fish species-specific manner. In 6 sites, correlations were found between parasite abundance and their hosts' feeding ecology. These effects were location-specific and occasionally host species or host size-specific. Overall, the results suggest a relationship between parasite infection and host trophic niche which may be an important and largely overlooked ecological factor. The population specificity and variation in parasite communities also suggest this effect is multifarious and context-dependent.
寄生虫如何改变宿主的摄食生态在自然种群中仍然难以捉摸。一种强有力的方法是在共同的环境中，量化相关宿主物种内感染与摄食生态之间的联系，从而研究感染与摄食生态之间的联系。在这里，在一系列淡水和半咸水栖息地中，对三种棘鱼和九棘鱼的 9 对同域种群进行了采样，以调查寄生虫如何改变宿主的摄食生态：（i）寄生虫群落组成的生物和非生物决定因素，以及（ii）寄生虫感染在多大程度上与 2 个物种的营养生态位特化相关，使用稳定同位素分析（15N 和 13C）。结果表明，寄生虫群落组成和宿主寄生虫负荷在不同地点和物种之间存在差异，并与溶解氧相关。还观察到，一种常见的直接感染寄生虫的双壳类吸虫的丰度以鱼类物种特异性的方式与宿主 C 相关。在 6 个地点，发现寄生虫丰度与宿主摄食生态之间存在相关性。这些影响是特定于地点的，偶尔也与宿主物种或宿主大小有关。总体而言，研究结果表明寄生虫感染与宿主营养生态位之间存在关系，这可能是一个重要且在很大程度上被忽视的生态因素。寄生虫群落的种群特异性和变异性也表明这种影响是多方面的和依赖于背景的。
