Infestation and histopathology of Anguillicola crassus in European eel in the Lake Bafa, Türkiye.

This study aimed to first detect and histopathologically confirm the Anguillicolacrassus parasite in European eel (Anguilla anguilla) from Bafa Lake in the Aegean region of Türkiye. As a result of external and internal parasitological examinations performed on 22 individuals with a weight of 42.08-1264.54 g and a length of 31.80-85.30 cm, the presence of parasites was detected. In macroscopic and microscopic examinations, the parasite A. crassus was found in the muscle, intestinal system, brain and swim bladder of the eels. The prevalence was found to be 35 %. Histological examinations confirmed the presence of A. crassus in the gills and intestinal system. In the examined silver and yellow eels, A. crassus eggs, mostly called L1 and L2 forms of A. crassus, were detected in the gills, intestinal system, and muscle. The adult form (L3-L4) was seen in the swim bladder and intestinal system. This study includes the first detection of the A. crassus parasite in eels in Bafa Lake. The unique value of this study is especially evident in the presence of parasites in the muscle, brain, gill and intestinal systems of eels.