Programa de Magíster en Ecología de Sistema Acuáticos, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Avenida Universidad de Antofagasta, 02800, Antofagasta, Chile.
Facultad de Ciencias del Mar y Recursos Biológicos, Instituto de Ciencias Naturales Alexander von Humboldt, Universidad de Antofagasta, Avenida Universidad de Antofagasta, 02800, Antofagasta, Chile.
Sci Rep. 2021 Jan 12;11(1):579. doi: 10.1038/s41598-020-79847-1.
Macro- and micro-environmental factors modulate parasite loads in fish, determining parasitic abundances, diversity, and interaction dynamics. In this study, seasonal variations in larval ectoparasites on fish larvae in the northern Humboldt Current System (HCS) were evaluated using a delta-gamma generalized linear model to predict their occurrence frequencies. Fish larvae were collected from two nearshore areas during austral spring-summer and autumn-winter. Only five (of 38) larval fish species were parasitized by copepods: Gobiesox marmoratus, Ophiogobius jenynsi, Helcogrammoides cunninghami, Myxodes sp., and Auchenionchus crinitus. A binomial model showed that the presence/absence of parasitized fish larvae varied among the fish species and their larval abundances, while a positive delta-gamma model showed that ectoparasite frequency varied among the seasons and fish species. Seasonal variations in parasitized fish larvae frequency could be associated with host and parasite reproductive processes, which are related to oceanographic features responsible for larval retention and subsequent higher infestation probabilities. Host length was positively correlated with ectoparasite length, suggesting early infection and combined growth until the detachment of the ectoparasite. Our results suggest that infestation patterns in larval fish species can be identified using delta-gamma models and that they respond to local (retention) and high-scale (HCS) processes.
宏观和微观环境因素调节鱼类寄生虫的负荷，决定寄生虫的丰度、多样性和相互作用动态。在这项研究中，使用伽马分布广义线性模型来预测幼虫外寄生虫在北 Humboldt 海流系统（HCS）鱼类幼虫中的出现频率，评估了鱼类幼虫季节性变化。在南春-夏和秋-冬期间，从两个近岸地区收集了鱼类幼虫。只有 5 种（38 种）幼鱼被桡足类寄生虫寄生：Gobiesox marmoratus、Ophiogobius jenynsi、Helcogrammoides cunninghami、Myxodes sp. 和 Auchenionchus crinitus。二项式模型表明，寄生虫感染的幼鱼的存在/缺失在鱼类物种及其幼鱼丰度之间存在差异，而正伽马模型表明，外寄生虫的频率在季节和鱼类物种之间存在差异。寄生虫感染的幼鱼频率的季节性变化可能与宿主和寄生虫的生殖过程有关，这些过程与负责幼虫保留和随后更高的感染概率的海洋学特征有关。宿主长度与外寄生虫长度呈正相关，表明早期感染和共同生长，直到外寄生虫脱落。我们的结果表明，使用伽马分布模型可以识别幼虫鱼类物种的感染模式，并且它们对局部（保留）和高尺度（HCS）过程有反应。
