Scientists have highlighted the threatened conservation status of the Red lined torpedo barb, Puntius denisonii, a popular aquarium fish.
Prasad, Ali and Raghavan summarised the current knowledge on Puntius denisonii in the latest issue of the journal Environmental Biology of Fishes, as part of the journal's regular Threatened Fishes of the World series.
Their paper claims that Puntius denisonii is officially regarded as "Endangered", and that the aquarium trade is responsible for the demise of the fish.
Population declineRaghavan, who wrote a paper on the "boom and bust fishery" of South India's Western Ghats region, said that the species has a highly fragmented distribution and is restricted to certain parts of the Chalakudy, Kallar, Periyar, Achencoil, Pamba, Valapatanam, Chaliyar, Chandragiri and Bharatapuzha rivers of Kerala.
Referencing an article by Matt Clarke of Practical Fishkeeping, Raghavan said that the species was still being exploited on a large scale, despite serious population declines.
A study undertaken by Gopi in 2000, which examined the freshwater fishes of Kerala State, found that Puntius denisonii was "rare". A 2006 study by Kurup and Radhakrishnan recorded the species as "very rare".
In 2004, a study by Sudhi claimed that the population was dwindling at an annual rate of 70%.
Juvenile captive-bred Puntius denisonii filmed at Aquarama 2007, Singapore.
Captive breedingThankfully, Puntius denisonii is being bred in captivity on a commercial scale in Indonesia.
However, at present consumer demand is not pushing retailers to demand captive-bred fish and it remains difficult to tell whether fish on sale in retail outlets are captive-bred or wild caught.
As a result of conservation concerns Practical Fishkeeping advises avoiding this species unless you can be sure stocks are captive-bred.
Prasad, Ali and Raghavan said that some fisheries research institutes had now initiated conservation programmes to breed the species in captivity.
The authors recommend that authorities generate data on population dynamics, stock characters and the life history of the fish.
They have also suggested that catch and effort is reduced through efficient fisheries management programmes, and have recommended that in-situ conservation strategies, such as no-take zones and protected areas, are established to help protect the future of the species.
Puntius denisonii is also seen on sale as Denison's barb and Miss Kerala and is known locally as Chorakanni and Chorakaniyan.
For more information see the paper: Prasad G, Ali A and R Raghavan (2008) - Threatened fishes of the world: Puntius denisonii (Day 1865) (Cyprinidae). Environmental Biology of Fishes (2008) 83:189-190.