Himalayan golden mahseer among Asia's largest freshwater fish

The golden mahseer remains one of Asia's largest freshwater fish, with historical records noting a specimen measuring 2.74 metres (9 feet) and weighing 54 kilogrammes (119 pounds) caught in India in the 1930s.

The species is found only in rivers flowing from the southern Himalayan range, particularly the Indus, Ganges and Brahmaputra basins covering Nepal, India, Bhutan and Pakistan. The Seti and Karnali rivers in Nepal — among the locations visited during the writer's expedition — are branches of the Ganges river system. The fish has also been reported in the Salween River, which forms part of the border between Thailand and Myanmar.

Distinctive profile

Its large-looking head and elongated body are suited to pushing through the fast currents of Himalayan mountain rivers. Its clearly golden, glittering scales are the origin of the name 'golden mahseer', while a slightly darker lateral line is another distinguishing feature.

During the trip, the fish were most often tempted using heavy spoon lures — an indication that it is also a predator, feeding on smaller fish.

The International Game Fishing Association (IGFA) record for the species stands at 29.9kg (66 pounds), taken from the Mahakali River in India in 2017. However, due to overfishing and habitat loss — especially hydroelectric dam construction — fish of even 30kg are now extremely difficult to find.

On foreign ground

There have been surprising reports of the same species in Papua New Guinea (PNG), although it is not a native fish there.

Between about 1995 and 1997, under a project involving the Food and Agriculture Organization (FAO) and the PNG government, juvenile golden mahseer were supplied from a hatchery in India to be released into the Yonki Dam. The introduction formed part of the FISHAID project, aimed at enriching fish species in the dam for local food security as well as game fishing.

The move, however, raised concern among environmentalists after some golden mahseer escaped downstream into the Sepik River system, with fears that their presence would threaten native and endemic fish species in PNG.