Henneguya corruscans n. sp. (Myxozoa, Myxosporea, Myxobolidae), a parasite of Pseudoplatystoma corruscans (Osteichthyes, Pimelodidae) from the Paraná River, Brazil: a morphological and morphometric study.

This paper describes the parasite Henneguya corruscans n. sp. which infects the gills of Pseudoplatystoma corruscans Spix and Agassiz, 1829 found in the Paraná River, Brazil. The parasites belong to the interlamellar-epithelial type as defined by Molnár (2002) [Molnár, K., 2002. Site preference of fish myxosporeans in the gills. Dis. Aquat. Org. 48, 197-207]. The spores examined had thin, smooth walls with symmetric valves; the total length of the spores was 27.6 (25-29)mum. The spore body was ellipsoidal in frontal view and biconvex in lateral view and they measured 14.3 (13-15)mum long by 5mum wide and 4mum in thickness. The polar capsules were small and elongated, equally sized, with a rounded posterior extremity and tapering anteriorly, and they corresponded more or less the half the length of the spore body; they were 6.8 (6-7)mum long by 2mum wide, and the polar filament formed 5-6 coils obliquely to the axis of the polar capsule. The tail was 13.7 (12-15)mum long and bifurcated shortly after the end of the spore body. The importance of the infection for the farming of P. corruscans is discussed.