Citron barb, a new barb species, spotted from Western Ghats Rivers of Maharashtra

Citron Barb (Pethia lutea), a new barb species discovered from Western Ghat Rivers of Maharashtra
(Image Courtesy: Ralf Britz/JOTT)

Researchers studying the fish diversity in Western Ghats Rivers have discovered a yet unknown species of fresh water barb from the Western Ghats River systems in the Indian state of Maharashtra. The new species belongs to the Pethia genus of fishes which constitutes barbs found only in South Asia and Myanmar region.

According to the researchers, the new species was collected from six different rivers flowing through Raigad and Ratnagiri districts of Maharashtra. The fish was spotted from Kundalika River, Ulhas River, Kal River and Savitri River flowing through Raigad district and also from Shastri River and Jagbudi River in Ratnagiri District in Maharashtra. The newly identified fish is usually found associated with plants submerged in the water. Moreover, it prefers unpolluted, fast flowing stretches in Western Ghats Rivers, say the researchers.

Now christened as Citron Barb, the newly identified fish has got its scientific name also, Pethia lutea. Lutea being the Latin word for yellow, the researchers felt that this could be the most befitting name for a barb with dark yellow body and iridescent scales. “The specific name ‘lutea’ is Latin for ‘yellow’ and is named for the characteristic bright yellow colored body of the fish,” they said.

Citron Barb qualifies for Endangered status

Pethia lutea has a set of characters which makes it different from its closest relatives in the same genus. According to the research study published in the Journal of Threatened Taxa, Citron Barb has a distinct humped nape and a complete lateral line which makes it distinctive. It has comparatively fleshy lips than its relatives and has a distinctive lateral fold on the snout, says the study. Apart from the difference in the distribution of scales and the number of rays in its fin, it is also distinctive for the absence of barbels.

Kundalika River stretch from where the Citron Barb was spotted
(Image Courtesy: Unmesh Katwate/ JOTT)

The study also recommends that the newly identified species be incorporated into the ‘Endangered’ category of IUCN Red List due to its restricted distribution and fragmented populations. Citron Barb, as per the studies conducted so far, is restricted to west flowing rivers of northern Western Ghats in the Indian state of Maharashtra.

The suggestion is also justified considering the ongoing threats to its habitat, like extensive sand mining and increasing pollution. The game is going to be tougher for this fish which loves unpolluted fast flowing river stretches since urban and industrial waste are severely polluting rivers in Northern Western Ghats, especially in Maharashtra. Moreover, existing and proposed irrigation projects and hydroelectric projects which will cut the flow of the water are also considered to alter the nature of its habitat threatening its survival.

Unexplored fish diversity of Western Ghats

The researchers has also reported another fish of the similar genus, Pethia punctata, for the first time from west flowing rivers of Maharashtra, hinting that the fish diversity of Western Ghats rivers in this region is largely unexplored.  According to the researchers, the new discoveries point out that there is no clear information regarding the distribution of fishes in Northern parts of Western Ghats and many known species here are yet to be formally described.

“There is an immediate need to focus our attention towards conservation of freshwater ecosystems and biota of this region. Because no conservation action plan will be possible in the absence of information on diversity and distribution of species”, says the researchers. 

Unmesh Katwate, Chetana Katwate, Rajeev Raghavan , Mandar S. Paingankar  and Neelesh Dahanukar co-authored the study.