The inclusion of Puntius denisonii, a strikingly beautiful fish found in the Kerala segment of the Western Ghats, in the IUCN Red List is an important step in the struggle to conserve the biodiversity of the hotspot. The endemic 15-cm-long shoaling species, known locally as “Miss Kerala” and commonly as the Denison barb, is sought after by aquarium enthusiasts for its attractive colouration. It has a flaming red streak running from its snout across part of the body. Exceptional good looks seem to have imperilled this inhabitant of fast-flowing streams to the point that the IUCN says it is now vulnerable. The deterioration of its habitat, already fragmented and restricted to a few rivers — notably the Cheenkannipuzha (a tributary of the Valapattanam river), Achankovil, and Chaliyar — poses as serious a challenge as the growing demand from the globalised ornamental fish market. For want of a monitoring mechanism, the Denison barbs are being massively harvested even in reserve forest areas. Fortunately, recognising the vulnerability of this fish to extinction in the wild, the Kerala government has initiated some action to curb unrestricted capture and export.
The scientific estimate of freshwater fish diversity in the Kerala segment of the Western Ghats is of the order of 207 species, including food, ornamental, and sport fishes. Many of these are under threat. Unfortunately, harvesting and trade in fish is not monitored closely, as in the case of other wildlife. This lacuna is highlighted by the IUCN in its Red List literature. Simultaneously, the scope for ‘river ranching’ — the cultivation of the species in captivity and its release in the wild — needs to be explored seriously. Some dedicated scientists in Kerala are working to improve the weak captive-breeding record of the Denison barb, but a low female-to-male ratio complicates the situation. Any success in boosting captive stocks could theoretically relieve pressure on wild populations, although strong vigil would be necessary to prevent fraudulent certification. For now, there is a good case for prohibiting the export of specimens, dead or live. Meanwhile, the State government must take effective action to mitigate threats to the habitat posed by mining, hydroelectric projects, deforestation, and urban expansion. India has a rich trove of inland freshwater fish diversity. The vulnerability of this fish underscores the need to aggressively protect it under wildlife and biodiversity laws.