Parasitic Fauna In Catfish From The Downstream Of Jialing River

The present author investigated various parasite species in catfishes obtained from downstream of Jialing River from Sep. 2004 to Mar. 2005. 259 specimens of 12 catfish species in all were dissected and 33 species of parasites were collected and checked, In all, there were 3 families, 3 genera, 5 species of flagellate;5 families, 5 genera, 6 species of ciliates;4 families, 4 genuses, 7 species of Myxosporea;1 family, 3 genuses, 5 species of monogenea;1 family, 1 genus, 1 specie of cestodes;3 familie, 3 genuses, 3 species of digenea;1 family, 1 genus, 1 specie of nematoma;2 family, 2 genus, 2 specie of Acanthocephala;1 family, 2 genus, 3 specie of crustacean. Of all, a new specie of Myxosporida.was found in liver, kidney and gonad of Pseudobagrus nitidus. The spores of the new species, named as Myxosoma mai sp. nov., was pyriform in thecal view and spind-shaped in sutural view;spore shell smooth and uniform in thickness;sutural ridge straight and rough;intercapsular process distinct and large;the two pole-capsules were different in size with one located behind the other;polar filament 5-6 circles in general.The region properties of parasites from catfishes of Jialing River downstream were detailed in there aspects: species of host, species of parasites and their infection rate and infection intensity, then the influence of parasites on local fishery was discussed. Parasite infection is heavy in Pelteobagrus vachelli, Pseudobagrus nitidus and southern catfish, especially in Pelteobagrus vachelli. In terms of parasites, such intestines parasites as Digenea, Acanthocephala and Cestoidea are among those possessed highest infection .The result is closely interrelated to the catfish inhabit and food preference of the fishes and characteristics of parasites.Also, it was found that infection rate and infection intensity of all parasites except Gangesia parasiluri are remarkably lower than those of previous investigation results. Some reported parasites were not found in the investigation. This may be attributed to a decrease in number of host and pollution of Jialing River.