Seasonal variation and identification of parasitic fauna of edible ornamental fish by using Light and scanning electron microscopic summery with special reference to histopathological tissue alteration of infected organ

Abstract

This communication deals with seasonal variation of protozoans of edible ornamental fishes of West Bengal, India. During this survey, more than 1556 edible ornamental fishes were collected from different fish farms, ponds, bherries and nearby markets of several district of West Bengal namely, Nadia, South 24-parganas, Hooghly, North 24-parganas, Birbhum, Purba Barddhaman and Paschim Barddhaman from November 2019 to December 2022. Three ciliate ectoparasites belonging to the genus Trichodina, Trichodinella and Tripartiella and three myxozoan parasites belonging to the genus Myxobolus, Thelohanellus and Kudoa has identified from edible ornamental fish namely, Anabas testudineus. The study shows ciliate parasites have a higher rate of infection than myxozoan parasites. The highest prevalence of ectoparasitic infection have been reported during the post-monsoon season, i.e., from November to February, followed by monsoon season while lowest prevalence has been observed during pre-monsoon season i.e., March to June, implying that environmental variables play a role in the spread of infections. The identification of these ciliates and myxozoans parasites were done by widely used staining technique, along with an ultra-structural study of the myxozoan parasites using scanning electron microscope. The current work also reveals the histopathological alterations in the gill and fin of Anabas testudineus, infected with myxozoan parasites along with an ultrastructural study using scanning electron microscope.