LAUSR

Abstract Genetic improvement by farmers is beneficial for species with low economic value, as a way for farmers to access good seed stocks, and to maintain genetic diversity. However, concern has been raised whether the simple selection method is effective for the currently poorly managed culture stocks with long domestication history. In this study, mass selection was performed in a culture stock of snakeskin gourami, Trichopodus pectoralis, Regan 1910, to determine whether a simple mass selection would give positive selection response. The selection was performed based on total length, whereby the cut-off total length for females was 20.80 cm while all males were recruited due to limited number of morphologically distinct males available. This resulted in selection differentials of 1.44 cm for total length in females, and 0.20 cm in males (realized selection intensity was 1.412 and 0.210 for females and males, respectively). The results of the growth trial showed a positive but low selection response (P