Introduction: Fish have recently proved their ability to quickly adapt to newly invaded habitats. The Chrysichthys nigrodigitatus, Silver Catfish is a highly
valued commercial fish in Nigeria and other West African countries due to its high nutritional content and market demand. Intra specific variations in the
silver catfish are critical for understanding the population dynamics. The study was designed to evaluate phenotypic differences and growth patterns in the Silver Catfish, across Southwestern Nigeria.
Aims: To correlate meristic and morphometric measurement, determine homogeneity and heterogeneity of the specie, and evaluate phenotypic
differences amongst the groups. Materials and Methods: One hundred and forty-five samples of C.
nigrodigitatus were collected from artisanal fishermen at four locations namely the Epe and Ojo Lagoon, Badagry Creek, and the Abeokuta River.
Morphological attributes were evaluated using sixteen morphometric measurements, and statistical analyses such as descriptive statistics, one-way ANOVA, and correlation analysis were performed
Results: Morphometric variations were observed in body length, head width and other variables with mean value of parameters ranging from 0.67±0.26 in
Head Depth at Epe to 23.164±3.57 in Total Length at Abeokuta. Samples from Abeokuta, Ojo, and Epe exhibited negative allometric growth (b <3), while
Badagry showed positive allometric growth(b>3).
Conclusion: This study highlights the importance of understanding intraspecific variations in C. nigrodigitatus and their ability to adapt to different
environments. Highlighting the benefits of phenotypic study in order to assess species population and conserve genetic trait. Variations between populations observed could be as a result of exposure to environmental constraints.