Length-weight relationships and condition factor of nine fish species from the Benghazi coast, Libya

This study aimed to investigate the length-weight relationship and condition factor of nine species collected from the coast of Benghazi, Libya. A total of 758 samples were collected from November 2024 to September 2025. Total length ranged from 15.01 ±0.435 cm (total weight: 50.11 ±4.646 g) in Parupeneus forsskali to 57.58 ±0.817 cm (total weight: 198.87 ±9.585 g) in Tylosurus imperialis. The slope parameter (b) values ranged from 2.68 (95% CI: 2.40-2.95) in Pseudocaranx dentex to 3.69 (95% CI: 3.22-4.17) in Hemiramphus far. Isometric growth patterns were observed in Symphodus tinca (b: 3.01), Merluccius merluccius (b: 2.95), Tylosurus imperialis (b: 2.73), and Trachinotus ovatus (b: 3.21). Positive allometric growth was found in Serranus scriba (b: 3.07), Parupeneus forsskali (b: 3.48), Hemiramphus far (b: 3.69), and Synodus synodus (b: 3.41), while Pseudocaranx dentex (b: 2.68) exhibited negative allometric growth. The relative (Kn) and Fulton’s (Kf) condition factors showed species-specific variation in body condition among the examined fishes. Mean Kn values ranged from 0.925 ±0.017 (Symphodus tinca) to 1.114 ±0.013 (Synodus synodus). In contrast, mean Kf values varied from 0.102 ±0.002 (Tylosurus imperialis) to 1.383 ±0.007 (Serranus scriba), reflecting differences in nutritional status, morphology, and environmental adaptation among species. This study provides basic biological data necessary for the management and conservation of species in Libyan marine ecosystems.