Histopathological Changes Caused by Parasites in Carangoides Bajad Fish in the Red Sea, Jeddah

Abstract

This research focused on discovering parasites in the fish Carangoides bajad (orange-spotted trevally) (Forsskal, 1775) that were captured from the Red Sea off Saudi Arabia. Carangoides bajad (n = 120) were collected during the spring and summer of 2019. Internal parasites were extracted and subjected to parasitological analyses and fish intestines were subjected to histopathological analyses. The average length and weight of Carangoides bajad were 39.88 ± 8.7 cm and 1.68 ± 0.58 kg, respectively. We identified Anisakis (17.5%), Lecithocladium (23.33%), and Bucephalus spp (29.17%) in the infected fish. Female fish outnumbered males, suggesting that sex significantly influence the prevalence of parasitic infections. Parasites, or evidence of parasitic infection, were not detected in small fish (weighing 0.5–0.90 kg or 1.0–1.49 kg, and 20.0–29.9-cm long). Similarly, the values of Fulton’s condition factor (K) ranged between 3.0–3.99 and 4.0–4.99, supporting the conclusion that these small fish were not infected with parasites. The data on larger fish (weighing 1.5–1.90 kg or 2.0–2.49 kg or 2.5–2.99 kg and length 20.0–29.9 cm or 30.0–39.9 cm or 40.0–49.9 cm or 50.0–59.9 cm) reveal that parasitic infections significantly influenced the length, weight, and Fulton’s condition factor (K) according to the prevalence and intensity of infection of Carangoides bajad. Histopathological examination revealed intestinal tissue damage; and 45% of inflamed tissues involved swelling of the intestinal villi. Further, we observed separation of the mucosal epithelia from the submucosa, proliferation of goblet cells, and lymphocyte infiltration accompanied by atrophy and lysis of intestinal villi. The present study demonstrates infection of Carangoides bajad with three types of parasites and documents their deleterious effects.