Assessing Morphometric Diversity and Growth Patterns of Channa punctatus in Distinct Freshwater Ecosystems of Tamil Nadu, India

The present study investigates the morphometric, meristic, and length–weight relationships of Channa punctatus populations from two freshwater habitats in Tamil Nadu — Madurai (Sakkimangalam) and Virudhunagar (Kullursandhai). A total of 207 specimens were analyzed to assess intra-specific variation and population differentiation. Standard morphometric measurements and meristic counts were recorded and statistically analyzed using Principal Component Analysis (PCA) and cluster analysis through PAST software (version 1.89). The length–weight relationship for the combined sexes was expressed as Y = 7.9616x – 80.664, indicating a negative allometric growth pattern where weight increased less proportionally than length. PCA results revealed that the first three principal components accounted for approximately 70% of total variance, highlighting significant morphological differentiation between the two populations, particularly in head and fin morphometry. Cluster analysis further indicated slight segregation between Madurai and Virudhunagar populations, possibly reflecting environmental influences such as water quality, food availability, and habitat structure. Despite partial overlap in morphometric traits, population-level distinctions were evident, suggesting adaptive divergence under localized ecological conditions. The findings underscore the value of integrating morphometric and meristic analyses in stock discrimination and fisheries management of C. punctatus.