The old reports of 8-9m sturgeons are not credible, as well as the 7m for the chinese paddlefish. But anyway, those animals can both reach enormous sizes. The beluga sturgeon Huso huso is recorded to reach about 6m and more than 1000 kg (a hypothetical and non existent 8m long specimen would weigh more than three times of this, but there were never records of such heavy sturgeons), and the chinese paddlefish is also recorded with recent photo material to reach well over 3m in length.
There are several freshwater species which reach all about the same maximum length in the range of about 2,5-3m, the giant Mekong catfish Pangasianodon gigas and santiwongsei, the arapaima, the wels and the alligator gar, with the first two catfish species being clearly the heaviest.
To come again of attacks on humans. Most accidents in saltwater are caused by sharks, some also by barracudas, morays and sometimes perhaps very large groupers (I don´t count stingrays, because they only defend and not attack to kill and eat). But in the whole there are not much fish which ever attacked humans, and most of them are sharks. The giant freshwater fish are all comparably harmless. Neither the arapaima nor the wels have big teeth, the don´t attack really large prey, because they have to swallow them whole. As far as I know there are also no records of alligator gars attacking humans. The giant mekong catfish are mainly planteaters and harmless anyway. So I think there was hardly ever an incident in which a big freshwater fish ever attacked a human. There are some few reports of big pikes which did bite swimming humans, but it is very probable, that this were accidents of the pikes, which thought the finger were small fish or so.
There are several freshwater species which reach all about the same maximum length in the range of about 2,5-3m, the giant Mekong catfish Pangasianodon gigas and santiwongsei, the arapaima, the wels and the alligator gar, with the first two catfish species being clearly the heaviest.
To come again of attacks on humans. Most accidents in saltwater are caused by sharks, some also by barracudas, morays and sometimes perhaps very large groupers (I don´t count stingrays, because they only defend and not attack to kill and eat). But in the whole there are not much fish which ever attacked humans, and most of them are sharks. The giant freshwater fish are all comparably harmless. Neither the arapaima nor the wels have big teeth, the don´t attack really large prey, because they have to swallow them whole. As far as I know there are also no records of alligator gars attacking humans. The giant mekong catfish are mainly planteaters and harmless anyway. So I think there was hardly ever an incident in which a big freshwater fish ever attacked a human. There are some few reports of big pikes which did bite swimming humans, but it is very probable, that this were accidents of the pikes, which thought the finger were small fish or so.
Particularly in India downstream of a cremation site.
