Diet and resource partitioning of juveniles of the scalloped hammerhead scalloped hammerhead and the blacktip Carcharhinus limbatus sharks co-occurring in Southern Gabon

This study investigates the diet of juveniles of the Scalloped hammerhead Scalloped hammerhead and the Blacktip shark Carcharhinus limbatus in southern Gabon. Stomach content analysis showed a strong predominance of teleost fishes in both species, with Pteroscion peli representing 37% of prey items in Blacktip shark and 49% in Scalloped hammerhead ; indicating a similarly specialized foraging pattern. Both species exhibited narrow dietary breadths (Bi = 0.30 and 0.20, respectively) and a high trophic overlap (Morisita–Horn index = 0.89). Stable isotope analysis revealed comparable δ¹³C values between species and slightly higher δ¹⁵N values in Scalloped hammerhead, suggesting a modest trophic elevation. When combined, the dietary and isotopic data demonstrated marked overlap in resource use, and the isotopic niche metrics confirmed the absence of clear trophic partitioning. These results provide the first comprehensive trophic characterization of juveniles of both species in southern Gabon and highlight their reliance on shared coastal prey resources during early life stages.