Radiographic and genetic characterization of phenotypically deformed Teleost from Gomti river, Uttar Pradesh, India

In the present study, we recorded two morphologically abnormal wild fishes from the Gomti river, Uttar Pradesh. Deformed Puntius chola (Hamilton, 1822) and Heteropneustes fossilis (Bloch, 1794) were observed in an experimental catch of the Gomti river at Lucknow and collected along with normal individuals of the same species for further investigation. Externally, the caudal region of fishes was completely deformed and fused. Abnormal and normal specimens of both species were identified using integrative taxonomy (traditional taxonomy and DNA barcoding). We created molecular signatures of each species using a partial sequence of the mitochondrial gene Cytochrome C oxidase subunit I (COI). Radiography is a non-lethal and non-invasive approach that can provide useful information about skeleton abnormalities in fishes. The radiographic images revealed different vertebral deformations like lordosis, kyphosis, scoliosis, fusion, and compression compared to the normal vertebrae. The total vertebrae were 30- 34 and 52-58 in P. chola and H. fossilis respectively. Different environmental and genetic factors could influence the development of these abnormal short-bodied phenotypes in the fish population of this river. High anthropogenic stresses, deficiency of vitamin C and phosphorous, and poor quality of water and habitat could be associated with skeletal anomalies in collected individuals. However, stress throughout the embryonic and early life stages may potentially be the cause of these spinal abnormalities. This type of abnormality is very rare in natural ecosystems. This is the first report of such a monstrosity in the ichthyofauna of the Gomti river, Uttar Pradesh. Our research findings contribute to understanding the health and environmental conditions of the Gomti river and may have implications for conservation efforts and management.