Morphometric characteristics, food of Tarpon atlanticus and water quality trends in the Ogudu creek Lagos, Nigeria
The morphometric characteristics and the food of Tarpon atlanticus as well as the water quality trend in Ogudu Creek, Lagos, Nigeria, where the fish was caught, were studied between January and May 2011. The air temperature ranged between 24 and 32 oC with mean value of 30.5 oC and surface temperature between 28.5 and33.5 oC with mean value of 31.0 oC. The pH varied from being alkaline (8.3) and acidic (3.97) with mean value of 6.13. Salinity at lowest was (12.80‰), the highest (24‰) with mean value of 18.4‰ while dissolved oxygen ranged between 4.3 mg/L and 8.6 mg/L with mean value of 6.45±1.01 mg/L. The total length of specimens ranged from 11.0 – 25.9 cm (Standard length 5.1 – 16.0 cm) and weight 1.97 – 76.93 g. The specimens showed a unimodal distribution. The length – weight relationship for the combined sexes exhibited a negative allometric growth (0.911). The fish stomach had fish parts, fish scales and unidentified mass. The condition factor ranged from 0.475 and 1.046. The morphometric analysis exerted a highly positive correlation among the body parts; the total length and body weight (r = 0.92), total length and standard length (r = 0.92). The results of the present study also suggest that T. atlanticus living in the same place showed morphological divergence.
Keywords: Stomach content, Condition factor, Fish length, Morphology, Unimodal distribution