On some biochemical contents of tapeworm <i>Proteocephalus osculatus</i> and its definitive host, <i>Silurus triostegus</i>

Fishes are increasingly reported as important economic national resources, with recent interest focused on their therapeutic potential in reducing some diseases, including cardiovascular ones, due to their unsaturated fats and omega 3 content. The present study aimed to determine the concentration of some biochemical contents in the tissues of the tapeworm and the intestinal tissue of its definitive host Silurus triostegus fish. A total of 63 fishes were brought to the laboratory and dissected for small intestine removal, and a tapeworm of Proteocephalus. osculatus was collected and washed several times with saline solution. Intestinal tissues of the infected and non-infected fishes and the collected parasites were compared for biochemical parameters. Protein, glycogen, lipids, creatinine, and urea were measured using standard methods. Infected fishes had their intestinal tissues with a significantly (p<0.05) lower protein (22.06±0.42 mg/g wet weight), glycogen (12.33±0.08 mg/100 ml of solution, and lipid (17.10±0.16 mg/g wet weight) than non-infected fishes (33.06±0.72 mg/g wet weight, 20.23±0.53 mg/100 ml of solution, and 27.26±0.45 mg/g wet weight, respectively). Conversely, urea (12.30±0.36 mg/dl) and creatinine (2.31±0.12 mg/dl) increased significantly (p<0.05) in the infected host compared to non-infected ones (10.66±0.22 mg/dl and 1.07±0.10 mg/dl, respectively). This study highlights the impact of P. osculatus infection on the biochemical composition of S. triostegus, providing insights into parasite-host metabolic interactions. The findings suggest that biochemical markers such as protein, glycogen, and urea levels can serve as diagnostic indicators of fish health and can be valuable for disease monitoring, improving the quality of fish and fisheries management for commercial and export purposes.