Abstract

Genetics of quantitative phenotypes of Silver Catfish (Chrysichthys nigrodigitatus) from River Taraba, Tella, Nigeria. Sixty (60) samples of Chrysichthys nigrodigitatus of different sizes were bought from artisanal fisherfolk. Phenotypic heterogeneity (coefficient of variability, CV, > 10%) and multiple modes in morphometric and meristic values were assessed to imply plasticity and taxonomic complications, respectively. Twenty-one (21) morphometric and nine (9) meristic attributes were measured in all the collected individuals to the nearest 0.01 cm. A total of 77.78% of meristic attributes were heterogeneous (CV > 10%). All the meristic attributes except DFR and CFR have heterogeneous status (CV = 6.83% and 6.85% respectively). Multiple modal was recorded only in PECFR-L. Among the meristic attributes, DFR does not correlate significantly with any other attribute while a total of 100% of morphometric attributes were heterogeneous (CV >10%). Meanwhile, multiple modes were recorded in 61.90% of the morphometric attributes with significant correlations. Also, meristic attributes have significant correlations with morphometric attributes. The studied C. nigrodigitatus strains was characterized by heterogeneity of quantitative phenotypic values, and the population can be taxonomically discriminated.

Keywords: Genetics; Morphometric; Meristic count; Heterogeneity; Quantitative Phenotypes