ICHTHYOPHTHIRIOSIS – CAUSE OF SIGNIFICANT LOSSES OF CARP FINGERLINGS

Abstract

Ichthyophthiriosis is widespread parasitic disease of fi shes caused by a ciliated protozoan, Ichthyophthirius multifi lis. Th is parasite is capable of affecting most of species of freshwater fi shes, including all cyprinids. The parasites usually can be found on skin and gill in the form of white prominent spots 0.1-1 mm in diameter, which looks as if the fi sh was sprinkled with grits. Within these tissues, infections cause localized lymphocyte infi ltration, focal necrosis and varying degrees of epithelial proliferation. Investigations were carrieed out during a last 10 years, while monitoring the health condition of carp fi sh. Diagnosis of ichthyophthiriosis was performed by clinical and microscopic examination. Disease was present in carps throughout their life, but the most susceptible were young categories. The parasites were present on the skin and gills earlier in 10-day-old fi ngerlings. The outbreaks are most common in spring, aft er overwintering when water temperatures increase and also does the parasite replication rate. High stock density, water quality and poor condition contribute to illness. Since the disease causes signifi cant losses of carp fingerlings it is necessary to perform its adequate controls and therapy. In order to prevent the disease it is need to to rear young fi sh separately from other fish categories, prevent weed fi shes from entering the ponds and employ hygienic and prophylactic measures. All technological measures which can improve the condition of fi sh are most eff ective against ichthyophthiriosis. It is important to add lime into the pond from time to time. Eff ective chemical treatments for I.multifi liis include copper sulfate, potassium permanganate, malachite green, salt and formalin. Malachite green is a teratogen, and prohibited for use, while copper sulfate, potassium permanganate and formalin are also under currently reviewing for the use as parasiticides in food fi sh. So that, non-iodized salt is the only permitted and safe therapeutic for the moment.