Meghalaya's new cave-dwelling fish adapts to streams overground
GUWAHATI An underground cave in Meghalaya, in focus for a conflict over a Shivalinga-like stone formation, has yielded a new-to-science fish that adapts to streams overground.
A team of zoologists, led by Kangkan Sarma of Gauhati University's Department of Zoology, has recorded Schistura densiclava as a new species of troglophile loach from Krem Mawjymbuin in the State's East Khasi Hills district.
A troglophile animal is essentially a cave-dwelling animal that can thrive and reproduce in epigean, or aboveground, environments. Krem means cave in the indigenous Khasi language.
Mr. Sarma and D. Khlur Baiaineh Mukhim are the lead authors of the study published in the latest issue of the Journal of Fish Biology, a peer-reviewed publication of the Fisheries Society of the British Isles. The other authors are Hrishikesh Choudhury, Rajdeep Das, Rejani Chandran, Rajeev K. Singh, Deisakee P. Warbah, Wandalin Lyngdoh, Uttam Kumar Sarkar, and Dandadhar Sarma.
A 206-metre-high cave, Krem Mawjymbuin, has a surveyed length of about 1.6 km. The newly described loach, a bottom-dwelling fish with barbels hanging from the mouth, was found in a cool, fast-flowing stream about 60 meters inside the cave, where the temperature was 18°C and oxygen levels were low.
Belonging to the Nemacheilidae family, Schistura densiclava is adapted to the dark, subterranean environment but can also survive in surface waters. According to the authors, it retains pigment and eyesight, unlike other cave-dwelling fishes such as Schistura papulifera or Neolissochilus pnar, also recorded from Meghalaya.
The newly described loach has a pale yellow-green body 'marked with 14-20 greyish black to faint black bars' and a thick stripe near the dorsal fin. This stripe gave the loach its name – densiclava, which means 'thick stripe' in Latin.
The study said the Schistura densiclava males are slimmer with irregular patterns and puffier cheeks, while the females are sturdier with consistent markings.
'Genetic testing confirmed it as a completely new species... The distribution of the new species is limited to the cave, which suggests endemism in this cave system,' the researchers said.
Schistura densiclava is the sixth cave-dwelling fish recorded from Meghalaya, three of which were described by Gauhati University scientists.
Krem Mawjymbuin, among the most difficult to access, is one of several complex limestone cave systems in Meghalaya. The cave was in the news in 2024 when the Mawsynram Dorbar Shnong, the traditional village institution that controls the area, cited ecological reasons for banning the worship of the Shivalinga-like structure inside it.
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