Malabar Danio

The Malabar danio was described in 1849 as Perilampus malabaricus by the English physician and zoologist Thomas C. Jerdon with the type locality given as Chalakudy River, a river in the southern Indian state of Kerala. The specific epithet refers to this fact, as southern India was then known as Malabar. The species was at a time incorrectly considered a synonym of Devario aequipinnatus, which is a valid name for a different species.

The Malabar danio is a widespread habitat generalist native to the lowest peneplains of both Sri Lanka and southern India. To be more precise, the Malabar danio occurs in lowland flood plains, hill streams, and mountain torrents up to 1,300 m above sea level, in various ecoclimatic zones whose waters vary in turbidity, shade, and disturbance levels.

The Malabar danio often forms medium-sized shoals close to the water surface. The Malabar danio is oviparous and is a group spawner. Interestingly, the Malabar danio would release a chemical called 7-hydroxybiopterin when injured; when sensed, this signal alerts conspecifics to swim rapidly away. This alarm mechanism has also been observed in other cypriniform fish species.

The IUCN Red List listed the Malabar danio as Least Concern as of August 2019. The IUCN had previously assessed this species as Least Concern in 2009 and 2011, suggesting that this species had had a relatively stable overall population. However, the Malabar danio does has threats, as there are many common issues plaguing other aquatic life in this region, including anthropogenic habitat alteration, agricultural pollution, the construction of dams, indiscriminate fishing, invasive species, and climate change. Additionally, due to the status of the Malabar danio as a popular aquarium fish, exploitation for the aquarium trade may also lead to population decline. Captive breeding programs for the aquarium trade in places such as Singapore, Thailand and Hong Kong have helped alleviate the pressure exerted by the aquarium trade on the wild population.