PDF(Pubmed)
Abstract：
Astyanax lacustris is a small characid fish widely distributed in Brazil, with fast-growing and omnivorous feeding habits. Although the species presents economic and ecological importance, little is known about its parasitological fauna in stream environments. This study aimed to characterize the parasitic fauna of A. lacustris in two streams in the state of Paraná, Brazil. Fifty-two specimens of A. lacustris were collected, 22 from the Carolina stream (Lower Iguaçu River) and 30 from the Carreira stream (Upper Paraná River), in July and September 2018. In both streams, there was a low richness of parasites, and the structure of the parasitic community was predominantly composed of monogeneans. These findings may be associated with the gregarious behavior of the host species. Moreover, the low occurrence of endohelminths, may be associated with the fact that in streams, the energy flow is low, and depends directly on the input of allochthonous matter, which favors the formation of shelters for the establishment of macroinvertebrates, which represent important sources of food for the ichthyofauna, and may act as intermediate and paratenic hosts of parasites. These environments require further studies to support conservation measures aimed at maintaining the balance of ecological relationships in these preserved ecosystems.
摘要：
落叶松是一种在巴西广泛分布的小型鱼类，具有快速生长和杂食的饮食习惯。尽管该物种具有经济和生态重要性，对河流环境中的寄生虫动物知之甚少。这项研究旨在表征巴拉那州两条溪流中A.lacustris的寄生动物，巴西。收集了52个A.lacustris标本，22来自卡罗来纳州河流（下伊瓜苏河），30来自卡雷拉河（上巴拉那河），2018年7月和9月。在这两个流中，寄生虫的丰度很低,寄生群落的结构主要由单系生物组成。这些发现可能与宿主物种的群居行为有关。此外，内蠕虫的低发生率，可能与以下事实有关：在流中，能量流很低，直接取决于异源物质的输入，这有利于建立大型无脊椎动物的庇护所，它们是鱼类的重要食物来源，并可能充当寄生虫的中间宿主和paratenic宿主。这些环境需要进一步研究，以支持旨在维持这些保存的生态系统中生态关系平衡的保护措施。
