Histopathology of gill parasites in cultured SEA BREAM (sparus aurata) and SEA bass (dicentrarchus labrax)

Objective: This study was carried out to define the parasitic diseases and histopathological findings of sea bream and sea bass, which are frequently cultured in Turkey. Materials and Methods: The material of the research; It consists of dead fish samples with suspected disease, which were brought to the Kanyon Akua Veterinary Clinic Disease Diagnosis Laboratory between January 2021 and January 2022. In the study; 5,250 fish, of which 3,150 were sea bass (D. labrax) and 2,100 sea bream (S. auratus) weighing between 2-200 gr, were used. After measuring the total length-weights of the samples, they were divided into groups of two for pathological and parasitological examinations. Results: As a result of the examinations, eleven different parasitic agents were detected, in which intense infestation was observed in sea bream and sea bass. Among these disease factors, those seen in sea bass; Lernantrophus spp., Diplectanum spp., Cryptocaryon spp., Amyloodinium spp., Trichodina spp., Apiosoma spp., Cryptobia spp., Costia spp. while those seen in sea bream; Microcotyle spp., Dactylogyrus spp., Furnestinia spp., Trichodina spp., Costia spp. Trichodina spp. and Costia spp. were seen both of them. The most common histopathological findings were lamellar edema, necrosis, hemorrhage, telangiectasia, lamellar fusion, spills, infiltration of macrophage, lymphocyte and eosinophilic granulated cells. Conclusion: The most common parasitic agent in the field sea bass was Diplectanum spp, while the least common was Apiosoma spp. The most common parasitic agent in sea bream was Microcotyle spp, while Costia spp. was the least common. The highest mortality (10%) and the most severe histopathological lesions were detected in Amyloodinium spp. It was observed that the severity of histopathological findings increased as the size of the parasite increased according to the type. The incidence of multiple agents (multi-parasitism) in the cases was higher than the incidence of single agents. Keywords: Gill, Histopathology, Parasite, Sea Bass, Sea Bream