Diversity of parasitic helminths of endemic fish species Astyanax bifasciatus (Characiformes, Characidae) of Iguaçu River basin, PR

• Grant number: 18/25839-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2019
• End date: December 31, 2019
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Inland Water Fishery Resources
• Principal Investigator: Igor Paiva Ramos
• Grantee: Bianca da Silva Miguel
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

Studies on parasitological aspects of Brazilian fishes often are related with species of economic interest, such as those used in aquaculture and aquarism. Thus, there are few studies on parasitological traits for small fish species and/or with no economic value such as Astyanax bifasciatus, an endemic species of the Iguaçu Basin. Therefore, the current proposal aims to characterize the helminth fauna associated with A. bifasciatus, in the lower Iguaçu River region. Thirty specimens of A. bifasciatus collected in Sep/2018 in the Carolina stream, PR, by electric fishing will be evaluated. The fish were euthanized, individualized, frozen and sent to the Biology and Animal Science Department of FEIS - UNESP, in the municipality of Ilha Solteira, SP. In the laboratory, the standard length (cm) and total mass (g) will have been measured, and the sex will be determined visually. Subsequently, they will have their skin and fins inspected for the presence of encysted helminths. All organs will be removed, isolated and examined with the aid of a stereomicroscope for the collection of parasites. The parasites will be processed according to Eiras et al. (2006) and morphological/morphometric analyzes will be carried out using a computerized image analysis system with Differential Interference Contrast - LAS V3 (Leica Application Suite). The parasite component community (richness, diversity, dispersion and discrepancy index), as well as the parasitological attributes (prevalence, mean abundance and mean intensity of infection/infestation) for each parasite species will be characterized. The relative condition factor will also be calculated in order to evaluate if there is any relation with the mean abundance of parasites.