Variation in the Morphometry Measurements of Two Tilapia Fish Species in Relation to Their Body Weight Obtained from Lower Benue River at Makurdi, Benue State Nigeria

摘要

This study examined the morphometry of Tilapia zilli and Oreochromis niloticus from lower River Benue atMakurdi. Seven morphometry measurements (body weight, standard length, total length, dorsal fin length, caudal finlength, head length and body width) of each captured fish. The mean of morphological parameters of Tilapia zilli ofbody weight, standard length, total length, dorsal fin length, caudal fin length, head length and body width were12.83 g, 8.00 cm, 9.95 cm, 4.50 cm, 3.19 cm, 2.27 cm and 4.44 cm respectively. Similarly the mean morphometry ofOreochromis niloticus was body weight: 15.51 g, standard length: 9.00 cm, total length: 10.76 cm, dorsal fin length:5.85 cm, caudal fin length: 3.68 cm, head length: 2.67 cm and body width: 4.41 cm. The correlation analysisbetween morphometry of Tilapia zilli was significant between head length and total length only. However, correlationanalysis between morphometry of Oreochromis niloticus revealed a significant positive correlation between standardlength and bodyweight, total length and body weight, standard length and total length, dorsal fin length and bodywidth and head length and dorsal fin length only. There was a strong relationship between log of body weight andstandard length using regression analysis with R2 value of 0.8689 in Oreochromis niloticus while a weak relationshipwas obtained in Tilapia zilli with R2 value of 0.0889 during the study. The study concludes that the two species of theTilapia are different with different morphological features used in its identification.