Folia Parasitologica 50[4] 263-268 (2003) | DOI: 10.14411/fp.2003.044

New data on Myxobolus longisporus (Myxozoa: Myxobolidae), a gill infecting parasite of carp, Cyprinus carpio haematopterus, from Chinese lakes

Iva Dyková^1,2, Ivan Fiala^1,2, Pin Nie³

¹ Institute of Parasitology, Academy of Sciences of the Czech Republic, Branišovská 31, 370 05 České Budějovice, Czech Republic

² Faculty of Biological Sciences, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic

³ State Key Laboratory of Freshwater Ecology and Biotechnology and Laboratory of Fish Diseases, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei Province, P. R. China

The original description of Myxobolus longisporus Nie et Li, 1992, the species infecting gills of Cyprinus carpio haematopterus L., is supplemented with new data on the spore morphology and pathogenicity. Spores are elongate pyriform with pointed anterior end, 15.7 (15.5-16.5) µm long, 6.7 (6-8) µm wide and 5.5 µm thick. Sutural ridge is straight and narrow. Mucus envelope is lacking. Two equal-sized elongate pyriform polar capsules are 8.5 µm long and 2.5 µm wide with convergent long axes. Polar filament coiled perpendicularly to the long axis of the capsule makes 9 (8-10) turns. Posterior end of polar capsules exceeds mid-spore by 15-20%. Cyst-like plasmodia are localised in the gill secondary lamellae. The infection is described in adult big host specimens. Gross lesions manifested as dark red colouration of gill tissues were restricted to the ventral part of the first gill arches. Remarkable site specificity (apical part of secondary lamellae) was observed in the course of development of microscopic lesions. M. longisporus is characterised also on the molecular level using sequences of SSU rRNA gene. Phylogenetic analysis based on these sequences has allowed clearer phylogenetic relationships to be established with other species of the genus Myxobolus sequenced to date.

Keywords: Myxozoa, Myxobolidae, Myxobolus longisporus, morphology, pathogenicity, SSU rDNA

Received: April 25, 2003; Accepted: July 25, 2003; Published: December 1, 2003  Show citation