Distribution and mechanism of the regulation of the pleurocercoid population count of Triaenophorus nodulosus (Cestoda, Triaenophoridae)

The character of the distribution of pleurocercoids of Triaenophorus nodulosus depending on the host age is shown. Their distribution in perch at the age of 0+-4+ is over dispersed in its character and is described by negative binomial. At the age of 5+ to 8+ the distribution of parasites is of regular character that is apparently due to changes in the mechanism of regulation of the parasites number. The regulation mechanism of the number of pleurocercoids of T. nodulosus is discussed.