Teratogenic skeletal abnormality in Etroplus Suratensis (Bloch, 1790): Insights from the Vellar estuary, southeast coast of India

Abstract

This study represents the initial observational documentation of taillessness deformity in the green chromide fish, Etroplus suratensis, collected from the Vellar estuary along the southeast coast of India. This species, valued commercially and ornamentally, habitats in estuarine and freshwater. Skeletal abnormalities, particularly during development, can significantly affect fish health, often signaling environmental contamination, especially by toxic elements. The study employed morphometric and meristic analyses to reveal distinct differences in body shape and skeletal structure between tailless and normal fish, confirming vertebral deformity in tailless specimens. The radiographic examination also supported these findings. Previous studies on heavy metal levels in the study area have indicated significant cadmium presence, a known inducer of fish abnormalities, suggesting a potential link between the deformity and cadmium contamination in Vellar estuary. Additionally, it highlights fish abnormalities as potential indicators of changing environmental conditions, including temperature, salinity, and pH fluctuations, which are reported to vary significantly in the study area.