title: High Infestation by Dawestrema cycloancistrioides in Arapaima gigas Cultured in the Amazon Region, Peru.
abstract: The aim of this study was to evaluate the presence of Dawestrema cycloancistrioides in semi-intensive fish farming of fingerlings of Arapaima gigas. Between September and November 2013, 60 individuals of A. gigas born in captivity, were collected in three concrete ponds, from a semi-intensive fish farm in the Peruvian Amazon. For the study of sclerotized structures, parasites were fixed in a solution of ammonium picrate glycerine and mounted in Canada balsam. To visualize internal structures, parasites were fixed in hot formaldehyde solution (4%) for staining with Gomori's trichrome. The parasitic indexes calculated were prevalence, mean intensity, and mean abundance. This study identified a high infestation of a monogenean D. cycloancistrioides in gills of A. gigas. The prevalence was 100%. The mean intensity and mean abundance of the parasite were 144.9 of parasites per individual. This study confirms the necessity of constant monitoring of fish in order to reduce fish mortality.
authors.affiliation: Department of Parasitology, Institute of Animal Biology, University of Campinas, 13083-862 Campinas, Brazil.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Mathews
authors.affiliation: Department of Biological Science, University of State of Mato Grosso, 78200-000 Cáceres, Brazil.
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Malheiros
authors.affiliation: Department of Tropical Aquaculture, Institute of Biology, National University of the Peruvian Amazon, 765 Iquitos, Peru.
authors.forename: Narda D
authors.initials: ND
authors.lastname: Vasquez
authors.affiliation: Department of Health, Safety and Environment, Enersul Limited Partnership, Calgary, Canada T2H 1M5.
authors.forename: Milton D
authors.initials: MD
authors.lastname: Chavez