Detection and Morphological Assessment of Parasitic Helminths in Sarpa salpa and Euthynnus alletteratus from the Misurata Local Market

Background and Objective: Parasitic helminths pose a significant threat to marine fish populations by increasing mortality, reducing productivity, and impairing growth; however, information on how feeding habits influence infection patterns remains limited in the Misurata Region. This study aimed to assess the prevalence, distribution, and pathological impact of helminth parasites in two marine fish species with contrasting diets: the carnivorous Euthynnus alletteratus and the herbivorous Sarpa salpa. Materials and Methods: A total of 140 fish specimens (70 per species) were randomly collected from the Misurata local fish market. The digestive tract and gills were examined for helminth parasites using standard parasitological and histopathological techniques. Parasites were identified morphologically, and infection prevalence, site specificity, and tissue damage were recorded. Differences in infection rates between species were statistically evaluated to determine the influence of feeding habits on parasitic burden. Data analysis was performed using SPSS version 26, applying independent two-tailed t-tests at α = 0.05. Results: Overall, 71.4% of the examined fish were infected with helminth parasites. Euthynnus alletteratus exhibited a significantly higher infection rate (70%) compared to Sarpa salpa (30%). Combined infections of the gastrointestinal tract and gills were more frequent in E. alletteratus, whereas single-site infections predominated in S. salpa. Severe histopathological alterations, particularly in the digestive tract, were more pronounced in E. alletteratus. The study documented a diverse helminth fauna, including the first regional record of Acanthocephala and a digenean species in E. alletteratus, as well as nematode larvae in S. salpa. Conclusion: The findings demonstrate that helminth infection prevalence, distribution, and severity are strongly influenced by host feeding behavior. This study provides the first baseline data on helminth parasitism in these marine fish species from the Misurata area. Future research should expand seasonal sampling and incorporate molecular identification to better understand parasite transmission dynamics and ecological impacts.