Rare Fish Species Rediscovered in Arunachal’s Siang Valley After Over a Century

Itanagar: A rare species of swamp eel—Moringua hodgarti—has been rediscovered in Arunachal Pradesh’s Siang Valley after more than 110 years. The elusive species was last recorded during the historic Abor Expedition of 1911–1912, and had remained undocumented since.

The rediscovery was made by a team of Indian researchers—Nilanjan Mukherjee, Rahul G Kumar, Surya Narayanan, and Aravind N.A.—who collected new specimens during extensive field surveys conducted between January and October 2022. Their research was recently published in the international peer-reviewed journal Zootaxa.

Commonly known as a swamp eel, the fish belongs to the Synbranchidae family and is characterized by its elongated body, absence of paired fins, and its unique ability to breathe atmospheric oxygen through specialized organs. The newly collected specimens measured between 177 mm and 211 mm in length.

Following detailed morphological analysis, the species was reclassified under the genus Ophichthys, and is now referred to as Ophichthys hodgarti. The original six specimens collected during the British expedition are preserved in the Zoological Survey of India (ZSI), Kolkata.

The researchers emphasized that the rediscovery points to major gaps in our understanding of cryptic freshwater biodiversity, especially in underexplored regions like the Eastern Himalayas. They called for increased scientific attention and conservation focus in remote areas such as the Siang Valley, which may harbor other undiscovered or long-forgotten species.