However, some film footage has changed all that.
The fish in question rejoices in the wonderful name of the Goonch - scientific name Bagarius yarreli - and previously, this fish was regarded as being a fairly chunky catfish, but nothing out of the ordinary. The three other species in the Genus - Bagarius rutilus, Bagarius suchus and Bagarius bagarius, usually top out at about a metre in length, and the consensus in the past was that Bagarius yarreli likewise never exceeded a metre in length.
However, when people started disappearing along the Great Kali river, and people started reporting seeing monster catfish, media attention soon turned to the area. As is usual with such stories, it was tempting to dismiss them as hyperbole, until biologists began investigating the story.
Apparently, the short stretch of the Great Kali river, where the attacks have been concentrated, has been used as a place to dispose of the remains of traditional funeral pyres, and it appears that some of the catfish have developed a taste for human flesh as a consequence of feeding on the corpses from the funeral pyres. However, since the only candidate fish that fitted the bill was Bagarius yarrelli, and no specimen bigger than about 90 cm had been found previously, the question remained: were there really monster catfish in the river?
Biologist Jeremy Wade, who is also a keen angler, set out to answer the question. As this video clip shows, someone took a photograph of an extraordinarily large specimen, reputed to have been 7ft 4ins long:
First, he caught some regular sized specimens of the species, as shown in this video clip:
The backward pointing teeth that this species possesses ensure that it is an efficient predator on other fishes, and also enable it to bring down prey such as ducks and geese, which it drags below the surface and drown s before devouring.
Having used the data from the regular sized specimens, to determine the size that an individual of this species would need to be in order to be a potential maneater, he caught this:
Which exceeded the record for the species by a large margin. A still photo of Jeremy Wade, with helpers holding the 161 lb catfish, can be seen here, here and here.
So, it looks like the "mutant catfish" really do exist. The specimen caught by Jeremy Wade far exceeds all previous known specimens of this fish both in length and body weight, and it is possible that even larger specimens are lurking in the waters of the Great Kali river. The modus operandi described for the reported attacks, fits with the feeding pattern of this fish upon such prey as waterbirds - attack from below, drag beneath the water, then feed at leisure.
So, if any of you are planning trekking holidays in southern Nepal, don't go skinny dipping in the Great Kali river. Not unless you fancy ending up as a catfish's lunch.
7' would be a different matter... 
