Fish species identification is of paramount importance in biological research, serving as a fundamental component for understanding species biology. In our study, we collected a total of 34 specimens, glassy perchlet fish (Parambassis lala) from the Surma River, Singari beel and Ratargul swamp forest. Those total length (TL) were ranging from 2.1 to 3.9 cm. The collected specimens showed morphological variation in meristic features and coloration, which can be resolved through molecular study. For molecular identification, we meticulously selected three individual fish samples, conducted DNA extraction, polymerase chain reaction (PCR), and subsequent sequencing. These efforts resulted in sequences of 638 base pairs each for the Cytochrome C Oxidase subunit I (COI) gene. In our genetic analysis, three specimens—demonstrated a high degree of sequence similarity, ranging from 97.76% to 98.56%, when compared to the reference sequence OL638214.1. This outcome confirms their classification as Parambassis lala, despite morphological differences.