| A new species of Demidospermus Suriano, 1983 is described from the gills of Auchenipterus osteomystax Miranda-Ribeiro, 1918 (Auchenipteridae), collected in the upper Paraná river floodplain, Brazil. The gills were removed and preserved in 5% formalin. Later the parasites were removed from the gills with the aid of a stereomicroscope and conserved in 70% alcohol. Some specimens were stained with Gomori’s trichrome, dehydrated in absolute alcohol and cleared with faia creosote to observe the internal organs. Other specimens were mounted in Hoyer’s medium for the study of the sclerotized structures. The present study describes a new monogenetic species, Demidospermus osteomystax n. sp., characterized by: tandem gonads; V-shaped haptoral bars with... |
