[ Analyse du régime alimentaire de Zanobatus schoenleinii (Müller et Henle, 1841) dans les sites de débarquement de pêche artisanale au large de Dakar, Sénégal ]
Volume 71, Issue 1, February 2024, Pages 118–126
Luc Bonaventure Badji1, Youssouph Diatta2, Almamy Diaby3, Khady Diouf4, and Christian Capape5
1 Institut Universitaire de Pêche et d’Aquaculture (IUPA), Faculté des Sciences et Techniques (FST), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
2 Laboratoire de Biologie Marine, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
3 Laboratoire de Biologie Marine, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
4 Laboratoire de Biologie Marine, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
5 UFR de Sciences et Techniques du Languedoc, Université́ Montpellier II, Montpellier, France
Original language: French
Copyright © 2024 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Stomachs of 852 individuals of Zanobatus schoenleinii were sampled at three fishing stations located in the Dakar peninsula to determine diet composition. Three indices (If, Cn and Cp) were used to determine prey occurrence. A feeding coefficient (Q) was used to classify prey into different categories and define the feeding strategy of the species. The results showed a high vacuity in the species, which is thought to be related to the maturation of the gonads and digestion ongoing after the capture of the animal. The food spectrum consisted of nine prey groups including crustaceans especially shrimps which were preferential prey in both cold (Q= 628.31) and warm seasons (Q= 1067.60) and annelids of the genus Nereis as secondary prey during both seasons. Other prey groups such as fish and mollusks were incidental. Comparisons between individuals of different sex, size and fishing area indicated an absence of sexual segregation due to similarities between the diets of males and females. On the other hand, differences between young and adult individuals would indicate a distinct spatial distribution between individuals of different size. With respect to the landing stations, the differences noted between Soumbédioune/Ouakam and Hann allowed to affirm that although the tiger ray feeds selectively on typical prey, it has the capacity to adapt its diet in response to variations in prey availability.
Author Keywords: Zanobatus schoenleinii, diet, occurrence index, feeding coefficient, Dakar Peninsula, Senegal.
Volume 71, Issue 1, February 2024, Pages 118–126
Luc Bonaventure Badji1, Youssouph Diatta2, Almamy Diaby3, Khady Diouf4, and Christian Capape5
1 Institut Universitaire de Pêche et d’Aquaculture (IUPA), Faculté des Sciences et Techniques (FST), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
2 Laboratoire de Biologie Marine, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
3 Laboratoire de Biologie Marine, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
4 Laboratoire de Biologie Marine, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
5 UFR de Sciences et Techniques du Languedoc, Université́ Montpellier II, Montpellier, France
Original language: French
Copyright © 2024 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Stomachs of 852 individuals of Zanobatus schoenleinii were sampled at three fishing stations located in the Dakar peninsula to determine diet composition. Three indices (If, Cn and Cp) were used to determine prey occurrence. A feeding coefficient (Q) was used to classify prey into different categories and define the feeding strategy of the species. The results showed a high vacuity in the species, which is thought to be related to the maturation of the gonads and digestion ongoing after the capture of the animal. The food spectrum consisted of nine prey groups including crustaceans especially shrimps which were preferential prey in both cold (Q= 628.31) and warm seasons (Q= 1067.60) and annelids of the genus Nereis as secondary prey during both seasons. Other prey groups such as fish and mollusks were incidental. Comparisons between individuals of different sex, size and fishing area indicated an absence of sexual segregation due to similarities between the diets of males and females. On the other hand, differences between young and adult individuals would indicate a distinct spatial distribution between individuals of different size. With respect to the landing stations, the differences noted between Soumbédioune/Ouakam and Hann allowed to affirm that although the tiger ray feeds selectively on typical prey, it has the capacity to adapt its diet in response to variations in prey availability.
Author Keywords: Zanobatus schoenleinii, diet, occurrence index, feeding coefficient, Dakar Peninsula, Senegal.
Abstract: (french)
Les estomacs de 852 de Zanobatus schoenleinii ont été échantillonnés dans trois stations de pêche situées dans la presqu’ile de Dakar afin de déterminer la composition du régime alimentaire. Trois indices (If, Cn et Cp) ont été utilisés pour déterminer l’occurrence des proies. Un coefficient alimentaire (Q) a été utilisé pour classifier les proies en différentes catégories et définir la stratégie alimentaire de l’espèce. Les résultats ont montré une vacuité élevée chez l’espèce, qui serait liée à la maturation des gonades et de la digestion se poursuivant après la capture de l’animal. Le spectre alimentaire était constitué de neuf groupes de proies dont des crustacés particulièrement les crevettes qui constituaient des proies préférentielles aussi bien en saison froide (Q= 628,31) qu’en saison chaude (Q= 1067,60) et les annélides du genre Nereis comme proies secondaires durant les deux saisons. Les autres groupes de proies tels que les poissons et les mollusques étaient accidentels. Les comparaisons entre individus de sexe, de taille et de zone de pêche différents indiquaient une absence de ségrégations sexuelle du fait des similitudes entre les régimes alimentaires des mâles et femelles. En revanche, des différences entre individus jeunes et adultes, indiquerait une répartition spatiale distincte entre individus de taille différente. En ce qui concerne les stations de débarquement, les différences notées entre Soumbédioune/Ouakam et Hann ont permis d’affirmer que bien que la raie tigrée s’alimente sélectivement sur des proies typiques, elle a la capacité d’adapter son alimentation en réponse aux variations de la disponibilité de proies.
Author Keywords: Zanobatus schoenleinii, régime alimentaire, indice de fréquence, coefficient alimentaire, presqu’île de Dakar, Sénégal.
How to Cite this Article
Luc Bonaventure Badji, Youssouph Diatta, Almamy Diaby, Khady Diouf, and Christian Capape, “Diet analysis of Zanobatus schoenleinii (Müller and Henle, 1841) in artisanal fishing landing sites off Dakar, Senegal,” International Journal of Innovation and Scientific Research, vol. 71, no. 1, pp. 118–126, February 2024.
