Morphological variations of Labeo bata populations (Teleostei: Cyprinidae) in six rivers of Bangladesh: a landmark-morphometric contribution

The morphological variations of bata, Labeo bata (Hamilton, 1822) was studied based on morphometric and landmark analysis to know the populations status in the northern and southwestern Bangladesh. Samples were collected from six river sources viz. Mathabhanga (MR); Kirtonkhola, Barisal (KR); Nabaganga, Jhenidah (NR); Padma (PdR); Jamuna (JR) and Punorvoba, Dinajpur (PR). Univariate statistics among 22 truss measurements and 15 morphometric characters revealed a significant inter stock variation (P 0.05, P 0.01, P 0.001) among all the samples. The first, second, third, fourth and fifth discrimination function (DF) accounted for 78.5, 9.6, 7.9, 0.0 and 4% respectively in group variability, conferring 100% of total along group variability. Two clusters were formed in Euclidean dendrogram, in which 1st cluster formed by Kirtonkhola river population and 2nd cluster formed by remaining population along with the five sub clusters (MR, NR, PdR, JR and PR). These analyses supported that ‘truss network’ is an effective tool for determining the population status and baseline information of L. bata.