By Our Reporter
SHILLONG, May 24: A team from Gauhati University’s Department of Zoology, headed by Kangkan Sarma, recorded a new species of troglophilic loach, Schistura densiclava, in Meghalaya.
The fish was found in Krem Mawjymbuin in the East Khasi Hills district, a region known for its complex limestone cave systems.
Belonging to the Nemacheilidae family, Schistura densiclava is adapted to the dark, subterranean environment but can also survive in surface waters. This marks the ninth such loach recorded by Sarma’s team, which has been actively studying cave-dwelling and hill-stream fishes across the Northeast.
Over the past decade, researchers have identified several previously unknown species of loaches and catfish in the region’s caves, some entirely blind and pigment-less — evidence of the area’s unique evolutionary adaptations and biodiversity.
Schistura densiclava was found deep inside Krem Mawjymbuin. Surrounded by dense forest and accessible only seasonally, the cave remains untouched by tourism or human activity, preserving its pristine condition.
This discovery raises the number of known cave-associated fish in Meghalaya to six, three of them described by the Gauhati University. Assam’s Education Minister Ranoj Pegu praised the scientific breakthrough on social media, calling it a proud moment for the region.
Unlike fully cave-adapted fish like Schistura papulifera or Neolissochilus pnar, which lack pigment and eyesight, Schistura densiclava retains both. It has a pale yellow-green body marked with 14–20 bold black bars and a thick stripe near the dorsal fin, which inspired its name — densiclava, meaning “thick stripe” in Latin.
Classified as a troglophile, Schistura densiclava can live in caves but hasn’t completely adapted to cave life. Researchers found it in a cool, fast-flowing stream about 60 meters inside the cave, where the water temperature is around 18°C and oxygen levels are low. Despite these harsh conditions, the fish thrives on a diet of shrimp, insect remains, copepods, and even bat droppings.
Sarma, the lead author, noted sexual differences; males are slimmer with irregular patterns and puffier cheeks, while females are sturdier with consistent markings. Genetic testing confirmed it as a completely new species.
The findings were published in the Journal of Fish Biology, a peer-reviewed publication of the Fisheries Society of the British Isles.