Alicja Bernad, Elżbieta Terech-Majewska, Kamila Szypczyńska, Joanna Pajdak, Patrycja Schulz, Andrzej K. Siwicki
ABSTRACT. Parasitic fish diseases are one of the key factors that disrupts the development of aquaculture in many countries, including Poland. They result directly in losses stemming from fish kills, or indirectly by decreasing fish resistance and condition. The cells of Ichthyophthirius multifiliis are spherical, and the disease caused by this ectoparasite is referred to as white spot disease, in reference to the main symptom. How the disease develops and the course it runs depends on the fish species, the intensity and prevalence of the infection, rearing conditions, fish age and condition, and the season of the year. This parasite has an expert system for adapting its developmental cycle to different climatic conditions, which means it poses a persistent threat to farmed fish. The aim of the study was to analyze the results of parasitological studies conducted at the Laboratory of Fish and Crayfish Diseases, Department of Veterinary Hygiene, Voivodeship Veterinary Inspectorate in Olsztyn on fish farmed in the Warmia-Mazury Voivodeship in 2014-2015. In total in 2014, 48 cases of the invasive parasite I. multifiliis were noted, including six cases of disease and 42 cases of parasite carriers. In 2015, the parasite was confirmed in 39 cases, seven of which were described as disease and 32 as carriers. Infections of this parasite were often accompanied by other ectoparasites and bacteria, which caused greater damage to gills and skin. These factors also occur in the aquatic environment and in healthy fish on the skin and gills and internal organs. The analysis of the results of studies performed by farmers with the aim of ensuring fish welfare and health confirm that it is necessary to perform systematic parasitological monitoring, especially with regard to I. multifilis, since it poses a threat as a parasite, but also as a potential vector of factors that are possibly pathogenic.
Key words: ectoparasites, parasitological diagnostics, Ichthyophthirius multifiliis, gill and skin diseases
Przyjęto po recenzji 30.05.2016 r.