Freshwater fish are those fish that live in rivers, streams, ponds, and lakes. Freshwater salinity level is lower than saltwater, usually less than 0.05%. The top 5 freshwater fish are rainbow trout, common carp, northern pike, bluegill, and electric eel.
Table of Contents
Rainbow Trout: A Popular Freshwater Fish
The rainbow trout is a species of freshwater fish native to the cold-water rivers and lakes of North America.
Size:
The average size of rainbow trout is about 20 to 30 inches.
Color:
Its color can vary depending on its habitat. Its typical color pattern includes:
A pink to red stripe runs along the length of its body, from gills to tail. It has a silvery-white belly and black spots on its back, fins, and tail.
Diet:
They are naturally omnivorous. Their diet consists of small invertebrates, small fish, insects, worms, and algae.
Behavior:
Rainbow trout can be both solitary and social. They are opportunistic feeders and actively seek food near the surface. Some rainbow trout like steelhead spend part of their lives in the ocean and return to freshwater rivers to spawn. They are cautious and will often dart for cover when threatened.
Caring in Aquariums:
Tank size:
Tank size should be a minimum of 75 gallons.
Water Temperature:
Maintain water temperatures between 50°F to 60°F.
Filtration:
Rainbow trout need high oxygen levels, so provide a filtration system to keep the water clean.
Hiding Spots:
Must provide hiding spots using rocks or aquatic plants.
Interesting Facts:
The color of rainbow trout can change based on their environment, age, and breeding conditions.
The maximum age of rainbow trout noted is 20 years.
In North America, Rainbow trout is the most popular game fish.
Common Carp: A Hardy Fish in Freshwater Ecosystems
The common carp is known as a freshwater fish found all over the world due to extensive introductions. They are highly adaptable in a variety of water conditions.
Size:
The average size of a common carp is about 30 inches.
Color:
Its color can vary depending on its habitat. Its typical color pattern includes:
Bronze, gold, and olive green with yellow or silverfish underbellies.
Domestic variants are found in different colors like orange, white, black, red, and blue.
Diet:
They are naturally omnivorous. Their diet consists of plant material, insects, and other aquatic organisms.
Behavior:
Common carp are peaceful and generally not aggressive towards other fish. They prefer the company of their kind, often forming a school in the wild. They find their food in the mud and are hence called bottom-dwellers.
Caring in Aquariums:
Tank size:
Tank size should be a minimum of 250 gallons.
Water Temperature:
Maintain water temperatures between 65°F to 75°F.
Filtration:
Common carp prefer clean water, so provide a filtration system to keep the water clean.
Hiding Spots:
Must provide hiding spots using rocks or aquatic plants.
Interesting Facts:
Sometimes they grow large, with some individuals weighing over 60 pounds.
The maximum age of common carp noted is 40 years.
Common carp can survive in low-oxygen environments.
Northern Pike: All About This Fierce Freshwater Fish
The Northern Pike is a predatory freshwater fish. They are found across Asia, North America and Europe. Their sharp teeth makes them unique.
Size:
The average size of northern pike is about 18 to 30 inches.
Color:
Their body is olive green to dark gray, with a yellow belly.
Diet:
They are naturally carnivorous. Their diet consists of small fish but also eat amphibians, birds, and other small mammals if available.
Behavior:
Northern pike are solitary hunters. They are mostly found in weedy or vegetated areas where they can hide and ambush prey. They are highly aggressive even preying on smaller pike.
Caring in Aquariums:
Tank size:
The tank size for single northern pike should be a minimum of 150 gallons.
Water Temperature:
Maintain water temperatures between 55°F to 72°F.
Filtration:
Northern pike needs high oxygen levels, so a filtration system must be provided to keep the water clean.
Interesting Facts:
Northern pike are capable of incredible bursts of speed when attacking prey.
They belong to an ancient group of fish, with fossils dating back millions of years.
Northern pike are popular among anglers.
Bluegill: The Colorful Freshwater Panfish
Bluegill are vibrant and hardy freshwater fish that adapt well to aquarium life.
Size:
The average size of bluegill is about 6 to 10 inches.
Color:
Their body is typically olive green on the back with a yellow or orange belly.
Diet:
They are naturally omnivorous. Their diet primarily consists of insects, small crustaceans, and zooplankton.
Behavior:
Bluegill fish are schooling fish. They swim in groups, mostly of 10 to 20. They are peaceful but males become territorial during the breeding season.
Caring in Aquariums:
Tank size:
The tank size for bluegill should be a minimum of 30 gallons.
Water Temperature:
Maintain water temperatures between 65°F to 80°F.
Filtration:
Bluegill also needs high oxygen levels, so a filtration system must be provided to keep the water clean.
Interesting Facts:
Bluegill is commonly targeted as panfish.
They can make quick movements to avoid predators.
They produce low-frequency sounds during mating, to attract mates.
Electric Eel: Nature’s Electrifying Freshwater Fish
The name electric eel is set due to its ability to generate electricity. Their body contains electric organs that work like batteries.
Size:
The electric eel is found in different sizes but the average size is about 8 feet.
Color:
Their body is typically grayish to olive-brown with a paler underbelly.
Diet:
They are naturally carnivorous. Their diet consists of fish, amphibians, birds, and even small mammals.
Behavior:
Electric eels are known for their aggressive hunting technique, electric eels use powerful electric shocks to incapacitate prey. They have poor eyesight and rely on electrical fields to move around.
Caring in Aquariums:
Tank size:
Tank size should be a minimum of 500 gallons.
Water Temperature:
Maintain water temperatures between 75°F to 82°F.
Filtration:
Electric eels also need high oxygen levels, so a filtration system must be provided to keep the water clean.
Interesting Facts:
A maximum of 840 volts is generated by electric eels.
Electric eels are a type of knifefish. Due to their resemblance to catfish, they are closely related.
FAQs
Q. 1 How can identify different freshwater fish species?
Ans. Freshwater fish species can be identified by shape, coloration, and fin type.
Q. 2 Where can I buy freshwater fish?
Ans. To buy freshwater fish, visit the fish farm or fish store nearest to you.
Q. 3 Which is the most colorful freshwater fish?
Ans. Betta fish is known as the most colorful freshwater fish.
Q. 4 What are some popular freshwater fish for beginners?
Ans. Due to their hardiness and easy care requirements, bettas, goldfish and mollies are popular choices for beginners.
