INCIDENCE OF LERNAEID PARASITE IN CATLA CATLA ON A FISH FARM

Two hundred fishes (Catla catla) were examined for Lernaeid ectoparasites at Matti-tal Fish Farm, Multan during 2008. Four species of the genus Lernaea recorded were L. polymorpha, L. cyprinacea, L. oryzophila and Lernaea spp. The overall prevalence of Lernaea polymorpha was (46%) followed by L. cyprinacea (37.5%), L. oryzophila (8%) and of Lernaea spp., (1%), respectively. The relationship between body weight and Lernaeid parasites showed that prevalence of L. polymorpha, L. cyprinacea and L. oryzophila was highest in weight group of 801-1200g (75, 75 and 25%) and lowest in weight group of 1-400g (44.68, 35.62 and 6.91%). While for Lernaea spp., maximum prevalence was observed in weight group of 1-400g (1.06%) the parasite was absent in other body weight groups. The difference was statistically significant (P 0.05). The relationship between body length and Lernaeid parasites revealed the maximum infestation of L. polymorpha, L. cyprinacea, L. oryzophila and Lernaea spp., 90, 80, 20 and 10% in length group of 31-40cm, and it was minimum (16.66, 11.40, 7.01 and 0%) in 11-20cm group, respectively. The difference was statistically significant (P 0.05).