A great decline has been witnessed in the minnow, Gymnostomus ariza (Hamilton, 1807) in the natural water bodies; a phenomenon that requires high consideration. Hence, the present research has been organized to focus on the quality feed production of this fish. Specimens of G. ariza from three distinct rivers (the Kangsha, the Atrai and the Jamuna Rivers in Bangladesh) were collected and subjected to form six breeding lines with15 species in each line. The progeny from these lines has been inspected phenotypically to assess the structure and shape variation of the population based on landmark and morphometric and meristic characters. After checking normality, One-way ANOVA disclosed that all morphometric, meristic and truss system measurements were dissimilar among the six lines, while line-4 exhibited significantly higher growth in all aspects. For the morphometric and truss measurements, the discriminant functions graph revealed a well-detached group of six lines indicating that the values differed significantly among the lines. The dendrogram constructed by means of morphometric and landmark data displayed one leading cluster of line-4 connected with all other lines combined. Considering the best growing line identified in the current research, the outcomes would be beneficial to promote the culture of this species, maintain proper conservation, attain successful management, and in addition, support further research with informative data.