Why in news?
Researchers studying flatfishes in the Bahuda estuary on the Odisha–Andhra Pradesh border have identified a new species of flounder named Pseudorhombus bahudaensis. Using DNA barcoding and careful analysis of body features, they distinguished it from the closely related Gangetic largetooth flounder (Pseudorhombus arsius).
Background
Flounders are demersal or bottom‑dwelling fish belonging to the order Pleuronectiformes. They have flattened bodies with both eyes on one side of the head, an adaptation that allows them to lie camouflaged on the seabed. Several species of the genus Pseudorhombus occur along the Indian coast and support local fisheries. Accurate identification is essential for managing fish stocks and preserving biodiversity.
Discovery details
- DNA barcoding: Scientists collected samples of flounders from the Bahuda estuary and sequenced their mitochondrial genes. Genetic analysis revealed two distinct lineages: one corresponding to the known species P. arsius and another representing an undescribed species.
- Morphological differences: Compared with P. arsius, the new species has a broader body, a different pattern of lateral line scales and variations in the number and arrangement of dorsal fin rays. These differences remain consistent across specimens.
- Distribution: Besides the Bahuda estuary, the researchers found the new flounder at Gopalpur and Penthakata along the Odisha coast, indicating that it inhabits shallow coastal waters and estuaries.
- Evolutionary history: Phylogenetic analysis suggests that P. bahudaensis diverged from its closest relatives approximately 17 million years ago, highlighting long‑standing diversity within the group.
Significance
- Biodiversity conservation: Recognising new species helps scientists monitor fish populations and develop conservation strategies tailored to each species’ ecology.
- Fisheries management: Correct identification ensures that catch limits and regulations are appropriate and prevents over‑exploitation of vulnerable species.
- Ecological insights: The discovery underscores the rich biodiversity of the Bahuda estuary and the need to protect this habitat from pollution and unregulated development.
Conclusion
The identification of Pseudorhombus bahudaensis adds to our knowledge of India’s marine fauna and illustrates the power of combining genetic and morphological methods. Continued exploration of estuaries and coastal waters is likely to reveal more hidden diversity and inform sustainable fisheries policies.
Source: The New Indian Express