The Fastest Freshwater Fish

The Rainbow Trout (Oncorhynchus mykiss) rates as the ninth fastest fish in the world, the highest ranking for any freshwater fish. The tenth spot is taken by the Sacramento Pikeminnow (Ptychocheilus grandis) but, with respective speeds of 8.0 and 6.7 metres per second, there is quite some difference between the two. OK – compared to the Black Marlin, which heads up the list at 36.1 metres per second, neither gets a look in when it comes to open ocean races but, still, this is a title that must have sporting implications.

Remembering basic physics, speed is a product of power relative to mass. The more powerful the engine the faster the car. A faster fish must therefore be one that is stronger (more muscular) and one that presumably fights harder too.

So – is the Rainbow Trout the hardest fighting freshwater fish too? I don’t think there would be many anglers agreeing with that statement; not because the physics is wrong but because there are plenty of other factors that come into play as well.

For one thing, most anglers only encounter the semi-domestic version of Rainbow Trout introduced to reservoirs, and these do not get as big as their ocean-going native cousins. That’s right – the native fish, found in the Bering Straight area, spend a portion of their life out to sea.

Out at sea, these fish find a wider variety of food and are able to grow much bigger and stronger. They also have a different colouration and so when they return to rivers to spawn they are often mistaken for another species. They are more commonly known as Steelheads – a term that originated in Alaska but which is also now used in Kamchatka and other Far Eastern parts of the Russian Federation.

Steelheads can reach 1.20 metres in length and weigh in excess of 25 kilograms. That’s 55 pounds in old money. These fish are terrific fighters and would make a memorable catch for any angler on any tackle. Fly-fishing is probably the most sporting, and thrilling, option – but many anglers find lures and baits effective.

The Rainbow Trout offers great sport for anglers in many spots around the world. I say great but not the best. That title is, perhaps, one best left to open debate. The species that wins this title will have to be powerful, and big – and offer some exceptional fighting characteristics. The battle is only a worthy one if the conclusion is not decided from the moment the hook is set.