Biodiversidade de parasitas de peixes da família Loricariidae (Teleostei: Siluriformes) procedentes do rio Sapucaí-Mirim, Brasil

• Ano de defesa: 2016
• Autor(a) principal: Franceschini, Lidiane [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Catfishes; Freshwater fishes; Ectoparasites; Endoparasites; Small Hydroeletric Power Plants; Multivariate Regression Trees; Pequenas Centrais Hidrelétricas; Árvore de Regressão Multivariada; Cascudos; Peixes dulcícolas; Ectoparasitas; Endoparasitas
• Link de acesso: http://hdl.handle.net/11449/138055

Loricariid fishes (Siluriformes) presents great intraspecific phenotypic plasticity throughout their ontogeny. The limited knowledge about the biological aspects, biogeographic patterns of distribution and high morphological variability of these fishes make the studies on biodiversity of this group difficult, including that about parasites. Therefore, the aim of this study was to survey the biodiversity of parasites of Loricariidae fishes from an area under the influence of the construction of Small Hydro Power Plants (SHPPs) in the Sapucaí- Mirim River, São Paulo State, Brazil. Moreover, the study evaluated the structure of parasitic communities of these hosts (at both the component community and infracommunity levels), assessing the possible variation in infracommunity abundance among sites and fish species based on explanatory variables (spatial, temporal, and host traits). During 2012 and 2013, two annual samples (dry/rainy seasons) were carried out, in eight sampling sites situated in the reservoirs of three SHPPs: Palmeiras, Anhanguera, and Retiro. Specimens of Loricaria prolixa, Hypostomus regani, Hypostomus ancistroides, Hypostomus strigaticeps, Hypostomus heraldoi, Hypostomus margaritifer, Hypostomus cf. margaritifer; Hypostomus topavae; Hypostomus aff. topavae and Hypostomus sp., were analyzed, totaling 334 fishes. Twenty-nine taxa were found, totaling 15,957 parasite specimens, and Monogena was the dominant group, which showed the greatest richness (13 taxa). The parasites were identified as follows: monogeneans Dactylogyridae, Gyrodactylidae and Microcotylidae in the gills and skin. Seven new monogenean species were found, belonging to Demidospermus, Trinigyrus and Heteropriapulus genera. Austrodiplostomum sp. metacercariae in the vitreous humor and celomatic cavity, and an unidentified metacercariae encysted in the liver and intestine (Trematoda). For Nematoda it was observed: Rhabdochona sp. (Rhabdochonidae), larvae of Procamallanus (Spirocamallanus) sp. and adults of Procamallanus (Spirocamallanus) inopinatus (Camallanidae); third-stage larvae of Contracaecum sp. (Anisakidae) and larvae and adult of unidentified nematodes (Nematoda gen. sp.). Besides helminths, Glossiphonidae hirudineans were found in skin, fins and oral cavity, infesting all the fish species, and mixozoans of the genus Myxobolus, parasitizing gills of H. ancistoides. Multivariate Regression Trees (MRT) were performed in order to verify the relative effects and interactions of factors related to the host traits (host species, body weight, and relative condition factor - Kn), temporal (season and year of capture) and environmental (sampling sites) on the abundance of parasite assemblage at several scales context (global, genus, and local scales). The effects caused by differences between host species were a determinant predictor on the parasite abundance of loricariids (global, genus “Hypostomus”, and local scales), and L. prolixa presented a greatest difference in the composition and abundance of their parasites in relation to Hypostomus spp.. Therefore, the spatial structure of the infracommunities evaluated was determined, especially, by the intrinsic differences among host species and by the structural complexity of the sampling areas assessed.