Allometric relationships in nine species of rays (Elasmobranchii: Batoidea) caught by the Ivorian marine artisanal fishery
Résumé
Allometric relationships were estimated for nine species of rays from the Atlantic coast of Côte d’Ivoire using length-weight and length-length regression analyses. All specimens were collected between February 2022 and May 2023 at the San-Pedro fishing port and the landing sites of Tabou, Grand-Béréby, Monogaga, Jacqueville, Abidjan, and Assinie. A total of 844 specimens were sampled (515 Raja cf. miraletus, 43 Raja parva, 82 Rhinobatos rhinobatos, 30 Rhinobatos albomaculatus, 13 Rhinobatos irvinei, 62 Fontitrygon margaritella, 51 Torpedo torpedo, 27 Dasyatis marmorata, and 21 Zanobatus maculatus). The results showed that most species exhibited negative allometric growth, with b values ranging from 2.376 to 3.378 for length-weight relationships and from 0.615 to 1.065 for length-length relationships. These analyses revealed significant variations in allometric coefficients among species, which may be attributed to ecological and anthropogenic factors specific to Côte d’Ivoire. Such differences highlight the need to better understand the growth dynamics of local ray populations for sustainable stock management. This study thus provides essential baseline data for the conservation of elasmobranchs in West Africa and emphasizes the importance of further research in this region.
