Analysis of morphometric and meristic characteristics of three cichlid species in central Iraq: farmed and wild

This study is designed to assess morphological dissimilarities between aquaculture and feral groups of three cichlid fish species, Coptodon zillii (Gervais, 1848), Oreochromis aureus (Steindachner, 1864), and Oreochromis niloticus (Linnaeus, 1758). Feral groups were collected from fishers operating in the Tigris River at Al-Zubaidiyah City, while aquaculture groups were attained from a breeding facility at Al-Zubaidiyah City, Iraq. Boxplots by variable and habitat revealed significant group disagreement. The cultured population exhibited higher meristic counts, and eventually, the two groups diverged. The cross-validated discriminant analysis using morphometric characters from all 896 specimens correctly classified 93.9% by variant of each species (Wilk’s lambda = 2.63 E-8, p < 0.001). The boxplot of meristic characteristics indicates that number of dorsal fin ray, number of anal fin ray, and number of pectoral fin ray values were higher in aquaculture habitat for all species except number of pectoral fin ray for C. zillii and pectoral fin ray for O. aureus. For number of gills rakers, number of the lateral line scales, and number of vertebrae all counts were higher in aquaculture specimens. The connection between the results of comparing the reared and feral groups of the three cichlid species’ identification and taxonomy is discussed.