Morphometric variation of Cork fish (Channa striata Bloch, 1793) from nine populations in Sumatra Island, Indonesia

The geographic isolation and specific character of local habitat could cause variation of morphological characteristics among Cork fish population in different locations. The plasticity of cork fish to adapt to the environment factors possibly has an impact on the different of specific morphological on fish population at different habitat. This study was conducted to investigate the traditional morphometric measurement and truss network differentiation of cork fish populations in different locations at Sumatra Island. Total of 394 cork fish specimens (consisting of 198 males and 196 females) were collected from nine different areas of rivers, swamp and lakes. The samples were analysed based on 14 morphometric (M) and 21 Truss Network Measurement (TNM) characters to find out the significant correlation of the fish on each area sampling. The transformed datasets were proceeded to multivariate testing using Discriminant Function Analysis (DFA) and Cluster Analysis (CA). The results showed that cork fish had 20 distinguishing predominant characters in the head and back of the body. Based on cluster analysis, those fishes were divided into 4 groups depending on geographical isolation except one floodplain population that differs from the other population groups. We revealed that phenotypic dimorphism for female cork fish had a dominant size compared to males in head region and tail fin region. Cork fish in the lake had a dominant body height size compared to rivers and flooded swamps.