Morphometric Measurements and Meristic Counts of Chrysichthys Nigrodigitatus (lacèpède, 1803) From Two Ecological Zones in Nigeria

This study reports the Morphometric measurements and meristic counts of Chrysichthys nigrodigitatus from two ecological zones in Nigeria that could be used to discriminate Chrysichthys nigrodigitatus from samples collected in Kainji and Asejire dams. Forty fish samples were used to determine the morphometric measurement and meristic counts. The morphometric characters were presented using principal component analysis (PCA) to show relationship and differences between the two water bodies and all the samples from Asejire were almost imbedded in that of Kainji due to the size of the fish samples collected and the most likely difference could be likely attributed to availability of another species of Chrysichthys in the Asejire dam or environmental factors. The meristic counts were similar with the exception of anal fin rays which revealed 13 in some samples collected from Asejire dam while that of Kainji dam did not exceed 12, this could be used to discriminate Chrysichthys nigrodigitatus from the two water bodies. Chrysichthys nigrodigitatus from Kainji and Asejire dam are not similar morphologically which means that morphological variations can be used as a mean of differentiating Chrysichthys nigrodigitatus from Kainji dam and Asejire dam, Likewise Meristic count also differ with the anal fin rays count. Therefore external features can be used to differentiate Chrysichthys nigrodigitatus from the two ecology zones.