LENGTH-WEIGHT RELATIONSHIP AND MORPHOMETRIC CHARACTERISTICS OF COPTODON ZILLI FROM ELEYELE LAKE, IBADAN, SOUTHWEST NIGERIA.

The purpose of this study was to examine the morphological traits of Coptodon zilli from Eleyele Lake in Ibadan, Southwest Nigeria. Fish specimens were procured from middlemen at the landing site in the lake from the month of February to July, 2024. A total number of thirty five (35) fish specimens were procured with an average mean weight of combined sexes is 84.64 ± 6.23. The fish specimens were measured using Vernier caliper in millimeters (mm) and measuring board for morphometric characters while virtual counting was done for the meristic characters. Sensitive top weighing balance was used to take weight of the fish to the nearest 0.1g. The morphometric characters measured were standard length (SL), total length (TL), body depth (BD), length of base of dorsal fin (LBD), snout length (SNL), eye diameter (ED), pre-dorsal length (PL), head length (HL), head width (HW), depth of caudal peduncle (DCP), distance between pelvic and anal fin (DPA), length of pectoral fin (LPF), length of pelvic fin (LPF), length of base of anal fin (LBA), pre- orbital length (POBL), distance between the two eyes (DBE) were taken. The mean meristic characters such as Number of spines in Dorsal(NSD), Number of rays in Dorsal(NRD), Number of Anal spine(NSA), Number of Anal ray(NAR), Number of Pelvic spines / No. of spines in Pelvic(NSP), Number of Pelvic rays(NPC), Number of caudal fin rays(NCFR), Number of pectoral rays(NPL) were counted. Length - weight relationship was calculated using least square regression analysis. The value for 'b' and `R' of Coptodon zilli (combined sexes) were 2.7534 and 0.9157 respectively, this revealed that Coptodon zilli in Eleyele Lake has negative allometric growth. The condition factor obtained showed the well-being of the fish. The condition factor for combined sexes, male and female were 1.84, 1.81 and 1.92 respectively. This showed that the lake support good and healthy growth of Coptodon zilli. To guarantee the sustainable production of this fish species in the lake, it should be monitored and protected.