Bagrus bayad, (Forskal, 1977) (Forskal, 1977)

Ademola, Babatunde Taofik & Yakubu, Fadila Yusuf, 2024, Ontogeny and stomach content analysis of Bagrus bayad (Forskal, 1977) in Zobe reservoir, Katsina, Nigeria, International Journal of Fisheries and Aquatic Studies 12 (1), pp. 46-50 : 47-48

Results

Size distribution of Bagrus bayad in Zobe reservoir: The total lengths of 126 samples of Bagrus fish obtained in this study ranged from 12.0 to 55.0 cm, and the total weights ranged between 16.9 and 1260.0 g, with a mean total length and weight of 20.43± 6.45 cm and 109.23±175.05 g, respectively ( Table 1 ). Of the 126 Bagrus samples obtained from Zobe reservoir, 110 (87.30%) contained food items in their stomachs. The proportion of stomach fullness across the various size classes of Bagrus in this study showed that a full stomach was not recorded among young Bagrus ( Table 1 ). Additionally, empty stomachs were also the highest among this group (36.5%). Adult Bagrus with empty stomachs had the least proportion in the sample obtained from Zobe Dam during this study.

Stomach contents

The important food items of B. bayad in Zobe reservoir were fish eggs, annelids, insects, bivalves, crustaceans, teleosts, and debris ( Table 2 ). The gut content of Bagrus in Zobe reservoir showed a considerable variation in the diet based on fish size. Insects had the highest percentage frequency (26%) among the young Bagrus ( Table 2 ). The percent frequency of occurrence was highest for crustaceans (28%) in the juvenile Bagrus , while in the adult Bagrus , the frequency of occurrence was highest for teleost fishes (46%) among the food items. Invertebrate groups dominate the gut content of young and juvenile Bagrus , with a cumulative percentage numerical abundance of 50.7% and 57.8%, respectively. In addition, debris was found mainly in the stomachs of young Bagrus , accounting for a percentage numerical abundance of 31%. Whereas, teleost fish had the highest numerical abundance in the adult Bagrus stomach content, with a value of 53%. Crustacean had the highest IRI among all food items in young (15.9%) and juvenile (10.89%) Bagrus in Zobe reservoir during this study. While teleost fish had a higher IRI in adult food items with a value of 77.46, Amphipods were well selected among the crustaceans by young and juvenile Bagrus , while adult Bagrus selected tilapia in Zobe Dam.