Light and scanning electron microscopy of Myxobolus porofilus sp. n. (Myxosporea: Myxobolidae) infecting the visceral cavity of Prochilodus lineatus (Pisces: Characiformes: Prochilodontidae) cultivated in Brazil

Abstract

Abstract. Myxobolus porofilus sp. n. is described infecting the visceral cavity of Prochilodus lineatus (Valenciennes, 1836) cultivated in São Paulo State, Brazil. The plasmodial form of the parasite is 3-5 mm in length and appeared compressed between the wall of the visceral cavity and the pyloric caecum, reposing on this organ. The spores are small (length 5.7 ± 0.3 µm, width 4.8 ± 0.2 µm; mean ± SD) and round to elliptical in frontal view. The valve surfaces are smooth and have sutural folds. The polar capsules are ovoid, small (length 1.6 ± 0

An ultrastructural and histopathological study ofHenneguya pellucidan. sp. (Myxosporea: Myxobolidae) infectingPiaractus mesopotamicus(Characidae) cultivated in Brazil

“…Molnár et al (1998) suggested that the site of development of Myxobolus macroplasmodialis the plasmodia occurred free in the visceral cavity of Salminus maxillosus (Characidae), but the site of development could have been the serous membrane of the visceral cavity or organs, from which the parasite became detached at an advanced stage of development. A similar localization was suggested by Adriano et al (2002) for Myxobolus porofilus (Adriano et al, 2002) found in the visceral cavity of Prochilodus lineatus. The swim bladder was the site of sporogonic plasmodia or of the extra-sporogonic proliferative stages of myxosporeans whose sporogonic stages occur in other organs (Lom & Dyková, 1995).…”

“…The dimensions were expressed as the mean ± standard deviation (SD). Smears containing free spores were stained with Giemsa's solution and mounted in low viscosity mounting medium (Cytoseal TM ) to provide permanent slides (Adriano et al, 2002). For histological analysis, the cysts were fixed in 10 % buffered formalin for 24 h, embedded in paraffin, cut into 4 µm thick sections and stained with hematoxylin and eosin and sirius red (Adriano et al, 2002).…”

“…Smears containing free spores were stained with Giemsa's solution and mounted in low viscosity mounting medium (Cytoseal TM ) to provide permanent slides (Adriano et al, 2002). For histological analysis, the cysts were fixed in 10 % buffered formalin for 24 h, embedded in paraffin, cut into 4 µm thick sections and stained with hematoxylin and eosin and sirius red (Adriano et al, 2002). For scanning electron microscopy, free spores were deposited on a coverslip coated with poly-L-lysine and fixed for two hours at room temperature with glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.2).…”

“…Molnár (2002) found plasmodia of Myxobolus cyprinicola (Reuss, 1906) in 14.6 % of the specimens of Cyprinus carpio examined in Europe and the intensity ranged from one to 11 plasmodia per specimens. Adriano et al (2002) reported a prevalence of 3 % for P. lineatus infected by M. porofilus and the fish with the highest parasitemia had only two plasmodia. There was no correlation between the chemical and physical properties of the water and the prevalence of H. pellucida.…”

“…In South America, 32 Henneguya species have been reported in freshwater fishes (Barassa et al, 2003), and are the most common myxosporean parasites of the fish, with the gills being the organ most frequently infected (Gioia & Cordeiro, 1996). A few histological (Martins et al, 1999;Adriano et al, 2002;Barassa et al, 2003) and ultrastructural (Rocha et al, 1992;Azevedo et al, 1997;Azevedo & Matos, 1989, 1996, 2002Vita et al, 2003) studies have been done on Henneguya, using Brazilian fish. The present study is part of an investigation into the ultrastructural and histopathological characteristics of myxosporean parasites of freshwater fish cultivated in Brazil.…”