Journal of the Marine Biological Association of India

Volume 28 Issue 1&2

On the incidence of the sporozoan-Thelohania prox duorara Inversen and Manning in commercially important prawns at Madras.

D. B. James

In the commercial catches at Madras, Penaeus semisulcatus and P. indicus were seen to be affected by the sporozoan parasite Thelohania prox duorara Iversen and Manning. The incidence varies from 0.5 to 2%. Among the infected prawns 87% belong to P. semisulcatus 13% to P. indicus. In both the species the infection starts after they reach a length of 130 mm. First, the parasite infests the gonad, then the liver and finally the body musculature. Both the sexes are more or less equally affected by the parasite. The infection becomes severe with advancing age. More number of diseased prawns were encountered during the night landings. A few specimens of P. monodon harvested at CMFRI Muthukadu Mariculture Farm near Madras were also seen to be affected by the parasite. Details regarding total length, weight, sex and degree of infection for a two-year period are discussed.

Date : 31-12-1986