MARCO KULE1*, EDMOND HALA2
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1Ministry of Agriculture and Rural Development, Fishery policy officer, Tirana, Albania, email: marcokule11@gmail.com 2Agricultural University of Tirana, Faculty of Agriculture and Environment, Department of Aquaculture and Fisheries, Kodër Kamëz, Tirana, Albania, email: hiedmo@ubt.edu.al Corresponding author; E-mail: hiedmo@ubt.edu.al Abstract The European eel (Anguilla anguilla) plays a significant role in the biodiversity and fishing activities throughout Europe and the Mediterranean Sea. However, their populations have declined drastically, now constituting less than 10% of their historical numbers. This decline is attributed to various factors, both human-induced and ecological, including an invasive parasitic disease caused by the nematode Anguillicola crassus. Research on this parasite in the freshwater systems of Albania is limited. This study, the first of its kind, investigates the level of infection caused by A. crassus in Lake Shkodra/Skadar, the largest lake on the Balkan Peninsula. In December 2024, a total of 141 silver eels were collected for sampling. Biometric data were recorded, and sagittal otoliths were removed for age determination. Infestation was assessed macroscopically by inspecting the swim bladder, and classical epidemiological parameters— prevalence, mean intensity, and mean abundance—were evaluated. The prevalence of A. crassus in Shkodra/Skadar Lake was found to be 36.9%, with higher infection rates observed in males and younger eels. The number of adult A. crassus parasites found per infected eel ranged from 1 to 5, with males exhibiting a significantly higher infection rate of 48.4%, compared to 27.8% in females. The positive cases were found in silver eels aged 4 to 10 years, with the highest prevalence noted in the 4-year-olds (30.96%). Further investigative work over several years is necessary to provide a more comprehensive understanding of the infection of migratory silver eels with A. crassus in Lake Shkodra. Keywords: European eel, Anguillicola crassus, swim bladder, parasite prevalence. |
