Investigation on some Ectoparasites in whiteleg shrimp,Litopenaeus vannamei farms

This study investigated the parasitological examination of the whiteleg shrimp,Litopenaeus vannamei in farmed fish which suffer from brownish gills and a decline ingrowth. The farm with a density of ۸۰.۰۰۰/acre. Samples weigh ۱۲-۱۷g and salinity of۳۵ppm. After examination we detect protozoan ectoparasites parasite in suspected shrimps;the protozoan Zoothamnium sp., Trichodina sp . and Epistylis sp. Were isolated. Thediagnosis method as a part of the protozoan ectoparasite examination was scrapping. Theprevalence rate of protozoan ectoparasites were, respectively, ۷۴.۱۷% for Zoothamniumsp., ۳۵.۸۳% for Trichodina and ۶۸.۳۳% for Epistylis sp. . Finally, with the use of hydrogenperoxide ۱.۵ml/۱m۳ and Vitamin C ۱kg/ton all infested shrimp were treated.