New fish species discovered in India's underground aquifers

An international team of researchers has identified a new aquatic species, Gangaichthys indonepalicus, inhabiting the underground aquifers of the Indo-Gangetic Plain. The fish, which measures approximately four centimeters, belongs to a newly discovered genus named Gangaichthys.

Adapted to a permanently dark environment, the species exhibits characteristics typical of subterranean life, including extremely reduced pigmentation and very small eyes. Unlike typical cave fish found in caverns, these specimens were discovered in wells accessing deep groundwater systems near the border of India and Nepal.

The discovery originated from a 2024 TikTok video showing a translucent animal emerging from a water well. This led scientists from Indian and Chinese institutions to conduct sampling in wells within the Indian state of Bihar. The findings were documented in the scientific journal ZooKeys.