Parasite Richness and Host Condition in Caranx caballus (Green Jack): Insights from Artisanal Fisheries of the Eastern Tropical Pacific

Parasites are integral components of marine ecosystems, providing insights into host biology, trophic interactions, and environmental variability. This study presents the first systematic characterization of the metazoan parasite community of the Green Jack (Caranx caballus) in the northern Colombian Pacific, a region designated as an Exclusive Artisanal Fishing Zone (ZEPA) but with limited parasitological research. Specimens were collected from the Cupica Gulf across wet and dry seasons, and parasitological analyses were conducted to evaluate parasite load, community structure, spatial distribution, and seasonal variation. Of 46 fish examined, 20 were parasitized (overall prevalence: 43.5%), with low infection intensities (1–3 parasites per fish). Nine parasite species were identified, including monogeneans, digeneans, and copepods. Copepods (Caligus sp.) represented the most species-rich and dominant group, while Allopyragraphorus caballeroi exhibited aggregated distribution. Parasite communities showed low richness and diversity, seasonal stability, and strong trophic linkages to crustacean prey, particularly brachyuran megalopa. Host condition was unaffected by parasitism, suggesting resilience under current infection levels. These findings provide the first reference on parasite richness and diversity for C. caballus in Colombia, extending the known distribution of several species within the Eastern Tropical Pacific and underscoring the role of parasites as biological markers for fisheries monitoring and ecosystem change.