Assessment of Anisakis Larvae Contamination in Atlantic Mackerel (Trachurus trachurus L. 1758) from the Western Libyan Coast

Abstract

Anisakis is a parasitic nematode of marine mammals that utilizes a wide range of fish species as intermediate or paratenic hosts. These larvae are commonly found in commercially important fish, posing public health risks and reducing marketability. Atlantic horse mackerel (Trachurus trachurus) is a known host for Anisakis third-stage (L3) larvae. This study aimed to investigate the presence, prevalence, and intensity of Anisakis larvae infecting T. trachurus from the western Libyan coast. A total of 108 random samples of T. trachurus were collected from the fishing port of Tripoli city. Morphological measurements (total length and weight) were recorded. Fish were dissected, and larvae were collected, counted, and morphologically identified at the genus level using light microscopy. The overall prevalence of Anisakis spp. was 99.07%. Larvae were predominantly found in the muscle tissue, with a lower percentage observed in the body cavity. The intensity of infection was higher in longer fish (19–22 cm), which harbored 35–50 larvae, compared to 10–15 larvae in smaller fish (17–18.5 cm). All larvae were identified as third-stage (L3) larvae of the genus Anisakis. The extremely high infection rate renders T. trachurus less desirable for human consumption and diminishes its economic value in the Libyan market. These findings highlight a significant public health concern and emphasize the need for preventive measures and molecular identification of the species involved.