All About The Fastest Freshwater Fish

It is clear that moving in water is more difficult than in air, so fish with a need to move quickly often have elongated bodies or are shaped like cylinders or torpedoes. This shape helps reduce the amount of friction caused by moving through water and tends to make them grow fast. The exact number of fish species worldwide is unknown, as it is believed that many species of fish remain undiscovered. However, scientists estimate that the total number of fish species in the world is about 33,600. 

With more than 31,900 species identified to date, about 51% of all fish species are found in freshwater — that's more than 18,000 different species. And they make up a quarter of all the vertebrates in the world. Of course, those are just the species that we know of. So, out of these species, whats the fastest freshwater fish? Fish species can reach speeds we didn't expect, let's find out the fastest swimming fish in freshwater.

Fastest freshwater fish

Rainbow Trout (scientific name Oncorhynchus mykiss) is ranked as the 9th fastest swimming fish in the world with fastest fish speed of 6.7 meters per second. This is the highest rank for any freshwater fish. Oncorhynchus comes from the Greek word for the hooked muzzle. It is a species of trout and is native to the freshwater tributaries of the Pacific Ocean and North America. Here's a quick overview of this fastest freshwater fish: 

  • Common name: Rainbow Trout
  • Scientific name: Oncorhynchus mykiss
  • Type: Fish
  • Diet: Carnivore
  • Average life span (in wild): 6 - 10 years
  • Spawn: Early to late spring (water temperatures at least 6 - 7 °C)
  • Size: 20 to 30 inches
  • Weight: around 8 pounds
  • Federal conservation status: Least concern

fastest freshwater fish

Appearance & Life cycle

Rainbow trout have an elongated body, 10-12 dorsal fin rays, 3-4 dorsal spines, and 8-12 anal fin rays. The fastest freshwater fish have star-shaped black dots on their body. Their body is usually olive to greenish-blue on the back with a belly white to silver. Besides usually showing a prominent red/pink streak. If these fastest freshwater fish are from lakes, sometimes they seem to lose all color and appear silvery. In addition, they have no teeth on the back of the tongue. 

Adult freshwater rainbow trout average 0.5 to 2.5 kg (1 and 5 lb) in riparian habitats, while lake life forms can reach 9 kg (20 lb). The record size for those living in freshwater is 31.27 pounds and the maximum recorded lifespan of a rainbow trout is 11 years. Adults have a broad red stripe along the lateral line, from gills to the tail, most evident in spawning males. In addition, the caudal fin of this fastest freshwater fish is square in shape and only slightly forked. The torpedoes-shape body allows it to reach the high speeds mentioned above, becoming the fastest freshwater fish.

fastest freshwater fish rainbow trout

Fishing Fastest Freshwater Fish

Other introductions into waters formerly free of fish or with severely depleted native fish stocks have created sport fisheries; and rainbow trout provide a great sport for anglers in many parts of the world. In Texas, because they do not usually breed here and cannot survive the summer in most areas, the species is mainly use in winter carry fishing. Each winter, several hundred thousand of these fastest freshwater fish are released in community fishing lakes around the state.

Rainbow trout - fastest freshwater fish also like to eat small insects in the water and on land, but larger adults will also prey on other fish. Part of their popularity as game fish is because they are very willing to eat a variety of bait, both natural and artificial, including corn, salmon roe, flour, cheese, bait night, and power bait. Artificial baits such as gyroscopes, spoons, and jigs are also very effective for fishing this fastest freshwater fish. 

fastest fishing

When fishing in the lake in the spring and fall, the water is cooler and we can find rainbow trout near the surface and are also more active. Pranking with spinners, flies, and spoons is a common tactic as well as hanging bait off the surface. As the water warms up during the summer months, fastest freshwater fish become a bit sluggish and seek out deeper, cooler waters, so fishing will need to take place at or near the bottom. To catch bottom-dwelling creatures, you'll want to fish with a slightly floating bait or troll with your lure near the bottom.

These fastest freshwater fish are excellent fighters and will be a memorable catch for any angler on any rig. Fly fishing is perhaps the sportiest and most enjoyable option, and many anglers report that lures and baits are also very effective.


Wild-caught and hatchery-reared forms of this fastest fish freshwater species have been transplanted and introduced for food or sport in at least 45 countries and every continent (except Antarctica). Introductions to locations outside their native range in the United States, Southern Europe, Australia, South America and New Zealand have damaged many native fish species. 

Several countries report the adverse ecological impact after the introduction of these fastest freshwater fish. They may affect native species by preying on them, competing or even transmitting contagious diseases, and hybridizing with closely related species (subspecies), therefore reducing genetic purity. One thing worth mentioning is that this fastest fish in freshwater is include in the list of the top 100 globally invasive species.


Freshwater resident rainbow trout usually live and spawn in shallow, oxygen-rich rivers with gravel bottoms. They derive from alluvial or limestone streams that are typical tributaries of the Pacific Basin but introduced rainbow trout have formed wild, self-sustaining populations in other rivers such as rocks and creeks. In the huge freshwater, these fish find a wider variety of food and can grow much larger and stronger (can also grow as long as 4 feet and weigh up to 53 pounds). They also have different colors and so when they return to the river to spawn, they are often mistaken for another species.

This kind of fastest freshwater fish breed naturally in cold water bodies. They have the habit of digging nests to lay eggs. A female can lay 700-4000 eggs/lay. After laying, the eggs are fertilize and incubated in the nest.

The rainbow trout roe is quite large, non-sticky, and submerged in water. The hatching time depends on the water temperature and ranges from 100 days at 3.9 degrees Celsius and 21 days at 14.4 degrees Celsius. The eye point period (the eye can be seen through the eggshell) until hatching is a long time so eggs can be transported from one place to another to hatch.

rainbow trout


Freshwater rainbow trout usually live and breed in small or slightly large, shallow, oxygen-rich rivers, under which the river is a rocky strip. The fastest freshwater fish grows in silt-rich or rocky streams, which are characteristic tributaries of the Pacific basin.

  • Temperature limitation: these fastest freshwater fish grow and develop best in water temperatures of 10 – 20 degrees Celsius. They are also resistant to higher temperatures up to 24 degrees Celsius for a short time. They cannot survive when the water temperature rises.
  • Dissolved oxygen threshold: Rainbow trout grow and develop well when the oxygen content is 7 mg/l. However, they can tolerate dissolved oxygen levels up to 6 mg/l. Therefore, the dissolved oxygen content is one of the most important factors when choosing a water body for salmon farming.
  • Nutrition: In the wild, when young, rainbow trout eat insect larvae, small crustaceans, and zooplankton. As adults, these fastest freshwater fish eat crustaceans (snails, mussels...), water insects, and even juvenile fish.

Fish are not only the most common denizens of the water but also the fastest. The fastest freshwater fish above leave an impression with unforgettable fights for many anglers! If you are a fisherman with a passion for fishing and an interest in fishing clothing, check out our best-selling models here. Protection Status