Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied bet...Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied between 12.50 and 29.80 cm and body weight 10-385 g. Annuli （growth rings） observed on the opercula bones of specimens with mean standard lengths 21.70 ± 1.4 cm had one real annulus, 24.80 ± 1.1 cm had two real annuli, 27.4 ± 0.9 cm had three real annuli indicating age one, two, and three （1 ＋, 2＋, 3＋ ） respectively. Growth rings observed on scales appeared as interruptions in the normal pattems of scales. Specimens with mean standard lengths of 21.3 ± 1.5 cm, 24.7 ± 0.8 cm and 27.35 ± 11 cm were interpreted to be ages 1＋, 2＋, and 3＋ respectively. The maximum age of samples, derived from annuli on both opercula bones and scales was 3 years. Specimens below 18 cm standard length did not register any growth mark. The mean lengths at the estimated ages obtained using both opercula bones and scales were not significantly different （P 〉 0.05, P 〉 0.01）.展开更多
文摘Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied between 12.50 and 29.80 cm and body weight 10-385 g. Annuli （growth rings） observed on the opercula bones of specimens with mean standard lengths 21.70 ± 1.4 cm had one real annulus, 24.80 ± 1.1 cm had two real annuli, 27.4 ± 0.9 cm had three real annuli indicating age one, two, and three （1 ＋, 2＋, 3＋ ） respectively. Growth rings observed on scales appeared as interruptions in the normal pattems of scales. Specimens with mean standard lengths of 21.3 ± 1.5 cm, 24.7 ± 0.8 cm and 27.35 ± 11 cm were interpreted to be ages 1＋, 2＋, and 3＋ respectively. The maximum age of samples, derived from annuli on both opercula bones and scales was 3 years. Specimens below 18 cm standard length did not register any growth mark. The mean lengths at the estimated ages obtained using both opercula bones and scales were not significantly different （P 〉 0.05, P 〉 0.01）.
