Length weight relationship, food and feeding habits and condition factor of Synodontis melanoptera and Synodontis courtetti from Lower River Benue, Benue State, Nigeria

Abstract

Length weight relationship, food and feeding habit and condition factor of Synodontis melanoptera and Synodontis courtetti from Lower River were investigated. The results show that total length, weight and condition factor of S. melanoptera male ranged from 25.50-47.00cm, 100.00-955.00g and 0.39-1.82. Total length, weight and condition factor of S. melanoptera female ranged from 22.50-45.70cm, 103.00- 963.00g and 0.55-2. Female S. melanoptera had higher mean total length (34.02±0.96cm), weight (518.20±42.58g) and condition factor (1.12±0.05) than the male with (33.15±1.21cm), 358.83±52.09g and 0.78±0.05 respectively. Contrastingly, the total length, weight and condition factor of S. courtetti male ranged from 21.48-44.40cm, 106.20-840.40g and 0.37-1.94. Total length, weight and condition factor of S. courtetti female ranged from 22.48-48.30cm, 106.20-946.10g and 0.34-1.76. Female S. courtetti had higher mean total length (33.40±0.85cm), weight (381.58±36.09g) and condition factor (0.89±0.40) than the male counterpart (32.30±0.87cm, 327.32±39.68g and 0.88±0.06 respectively. The ‘b’ values for male, female and combined sexes of S. melanptera were 3.62, 3.32 and 3.45, with high correlation coefficients of 0.91, 0.92 and 0.90, respectively. Male S. melanptera had better ‘b’ value (3.62) than the female (3.32). Also, the ‘b’ values for male, female and combined sexes of S. courtetti were 3.16, 3.10 and 3.12 with high correlation coefficients of 0.83, 0.85 and 0.84, respectively. Higher ‘b’ value (3.16) was recorded for male S. courtetti than the female (3.10). The most frequently food item consumed by S. melanoptera and S. courtetti were stones; while S. melanoptera consumed 61.64% of this food item, S. courtetti consumed 86.44% followed by worms. S. melanoptera consumed 45.21%, S. courtetti consumed 69.49% whereas, the least frequently consumed food item by S. melanoptera and S. courtetti were crayfish (4.11%) and unidentified food item (10.17%), respectively. Numerically, the highest food item consumed by S. melanoptera and S. courtetti were worms (Nematode); S. melanoptera accounted for 31.90% while S. courtetti accounted for 34.57%. Crayfish (3.33%) and unidentified food item (5.76%) were the least food items consumed by S. melanoptera and S. courtetti.

Keywords: Length-weight, food and feeding, condition factor Synodontis melanoptera, Synodontis courtetti