Morpho-meristic characteristics and growth pattern of walking snakehead (Channa orientalis) collected from different locations of Northwestern Bangladesh

Abstract

This study aimed to reveal the morphometric and meristic variations, length-weight relationships, and condition factor of Channa orientalis collected from three regions (Kurigram, Rangpur, and Lalmonirhat districts) of Northwestern Bangladesh. Fifteen morphometric and six meristic characteristics were selected. Eight morphometric characteristics were significantly different (p<.05) among the regions; three characteristics were highly significant (p<.001) in Kurigram (Pre-orbital distance, PrOD; Lower-jaw length, LJL; Upper-jaw length, UJL) indicating C. orientalis population of Kurigram was significantly different (p<.001) from the other two locations. On the other hand, among six meristic characteristics, number of dorsal fin rays (DFR), pectoral fin rays (PFR), anal fin rays (AFR), and branchiostegal rays (BR) were found to be significantly different among three locations. The values of PFR varied significantly (p<.05) in Kurigram, which distinguishes the other two regions. Likewise, DFR and BR showed significant variations in the Rangpur region, whereas AFR significantly (p<.001) separated the Lalmonirhat population from the others. In length-weight relationships, the generalized relationship between total length (TL) and body weight (BW) were BW=0.007TL3.147 (r2=0.945), BW=0.03TL2.573 (r2=0.916) and BW=0.008TL3.084 (r2=0.899) for Kurigram, Rangpur, and Lalmonirhat, respectively. The growth pattern showed positive allometric in Kurigram (b=3.14) and Lalmonirhat (b=3.08). Negative allometric was observed in Rangpur (b=2.57). The study exhibited a higher condition factor (K) value in Kurigram (1.068) and Rangpur (1.049) whereas the lowest in Lalmonirhat (0.978). The study reveals that the C. orientalis population`s morpho-meristic and growth status were comparatively better in Kurigram region.