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About 67% of people in America own a pet according to a study by The National pet owners survey conducted in 2019. The same study found that fish are now the third most popular pets after dogs and cats.

This is because fish are aesthetically pleasing, will not take too much space, and are easy and cheap to maintain. Rearing of fish or even looking at them for short periods has also been linked to health benefits like lowered heart rate and blood pressure and reduced stress.

One of the most common fish types used as pests nowadays is the “pacu”. This is a freshwater fish under the Serrasalmidae species. This species also includes the piranha, but unlike these, pacu fish are very peaceful.

They have flat, broad bodies with fins on their bellies and backs. The males have sharper dorsal fin extensions and more brightly colored bodies compared to the females.

Pacu fish primarily have solid colors like silver, black, white, and gray. A few breeds like the red-bellied pacu nonetheless have flashy hues while the black-ear pacu fish has markings.

One of the distinctive features of pacu fish is, however, their human-like teeth. They have two blunt molar sets used for the grinding of plants and cracking of nuts. Moreover, they develop a personality as they get older and can even recognize their owners at times.

The following are other tidbits to answer the common questions you might have about rearing pacu fish.

Pacu Fish Natural Habitat

Pacu fish are freshwater fish that originate from subtropical and tropical South America. Here, their natural habitat includes flooded forests, lakes, and rivers from the Amazon depths to the river plate basin.

There are several species of pacu fish found in different regions of the world because some pet owners release them into the wild after they grow too big for aquariums. You thus can now find the fish in New Jersey, the cold Seine waters, the coasts of Florida seas, and Swedish waters.

Pacu fish are highly adaptable. They hence detect any unfavorable conditions in their environments then adjust their behaviors accordingly.

They, for instance, can change their habits to adapt to low nutrient and oxygen levels in the water. Even so, the fish will often migrate if these conditions are prolonged.

Pacu Fish Tank Requirements

The pacu is a large fish, they can grow up to 12-24 inches (30-60 cm). Some people opt for a small tank when buying juvenile pacu fish. This will mean upgrading the tank in the future.

As such, it is cost-effective to get a large tank for pacu from the get-go. A 500-1000-gallon tank ordinarily suffices for a fish tank. The tank should be clean and have adequate water filtration to be conducive for pacus.

The fish generally occupy the center of your tank since this has enough swimming space. When designing your fish tank, have a range of plant décor, driftwood, and roots so that the fish has enough places to hide and feel comfortable. Do not have live plants in your fish tank since the pacu will devour them.

Ensure the place you position the tank is quiet because small vibrations and movements of the tank will cause pacus to panic. When panicked, the fish will bang the sides of your tank and the appliances in it, causing extensive damage. Moderate to natural lighting is also essential for your pacu fish tank.

Pacu Fish Water Conditions

As juveniles and fry, pacus are found around and in the floodplains in tributaries that are rich in nutrients. As they mature, the fish move into the main waterways.

In your fish tank, the ideal water PH is one between 6.0-8.0 to mirror the natural habitat of the pacu. The water temperature should be maintained at 75-181 degrees Fahrenheit with a hardness range of 2-15 dGH.

The water should be clear, and its movement moderate. This means that a basic fish water tank setup will suffice for pacu fish. Pacus are messy fish.

You thus should change 30-50% of the water in your tank twice weekly, according to the bioload of your tank. This keeps your fish healthy and happy.

Pacu Fish Diet and Feeding Schedule

Pacu fish are omnivores. In the wild, their dietary requirements will change according to the seasons. In the wet seasons, the fish will heavily rely on the seeds of riparian plants. In the dry season, their main diet is small fishes and crustaceans.

In your fish tank, pacu fish will eat almost anything because their human-like teeth allow them to grind anything. You can consequently offer them a pellet diet or frozen foods. Pacus in fish tanks can also eat small fish.

This means you should be cautious of the tank mates you have for them. In their juvenile stages, flakes make a large portion of the diets of pacus. As they grow older, these fish should be ideally fed on quality pellets mixed with blood worms and occasional worms.

You, however, should not give the fish too many worms and shrimp since these have been shown to make them picky eaters.

To supplement the pacu’s vegetable requirements, you can include lettuce, spinach, zucchini, and broccoli in the diet. Fruits like raspberries, strawberries, and grapes in moderation can meet the pacu’s dietary needs. Pacu fish will also enjoy almost all types of nuts, including walnuts, almonds, and peanuts.

Some pet owners opt to feed live goldfish to their pacus. These are readily available and affordable, and might to most people seem like a good idea. Even so, live goldfish usually transmit different diseases to your beloved pacu fish and are not very nutritious.

As some of the largest Amazon fish, pacus need large food amounts and often feed in several ‘’bite events’’. Each event comprises several individual bites, much like the feeding habits of the piranhas. To mirror these feeding habits in your fish tank, you should feed pacus several times throughout the day.

Pacu Fish Tank Mates

Pacus are not particularly aggressive fish but are best kept in the same tank as fish of the same species. While young, the fish prefer being in schools, but as they mature, most are solitary and might not need companionship.

The best choices for tank mates for pacus are fish that are neither excessively timid nor aggressive. These include the green terror, tiger Oscar, and managuense cichlid.

The green terror is a brightly colored cichlid whose body is covered with blue scales. It is about 6-8 inches long with a face that has patterned stripes. Its lifespan is 7-10 years, and it is omnivorous, just like the pacu fish.

The Tiger Oscar is a brightly colored cichlid that grows to maximum sizes of 35cm. It is a native of South America and has a lifespan of about ten years. Its feeding requirements closely mirror those of the pacu, so its maintenance will be no issue.

The managuense cichlid is also called the jaguar cichlid because of its black or brown spots on a silvery background. It grows to lengths of about 40cm and has an average lifespan of 15 years. Like the pacu fish, the jaguar cichlid is omnivorous.

Pacu Fish Breeding

Reproduction in the pacu fish is by spawning. Instead of mating like most fishes, the female fish will reproduce unfertilized eggs into the water. The male pacu will then release sperm after this to fertilize the eggs.

The fish often release 150,000-200,000 eggs, but some females can release a million eggs at a time. The juveniles that are hatched afterward are immediately independent and will not need the adult males and females to survive.

It is often impossible for you to breed the pacu fish in a fish tank because of its size. As such, most pacu fish species are bred in ponds and farms using artificial hormones.

If, however, your tank is large enough for breeding, you should separate the eggs laid by your fish from the parent. This is because pacus will sometimes eat their eggs after laying them.

Wrapping Up

Like most giant fish, disease is a typical concern when rearing a pacus. The fish are, however, quite hardy, and few diseases will affect them in well-maintained fish tanks. You thus should be vigilant not to introduce any disease-causing elements into your tank.

The decoration used in your tank, as well as the food for your fish, can introduce bacteria into the tank or upset its balance. Before putting live feed into the tank, for instance, quarantine it to reduce the risk of infecting the tank’s environment.

The tank’s environment should also mirror the natural environment of pacu fish as much as possible. This is because this will make the fish less stressed and boost their resilience to disease.

You can choose from several pacu fish species for your fish tank. The most popular include the black, black-fined, red belly parrot, and small-scaled pacus.

These have lifespans of 20-25 years. Pacu fish as pets can be shipped worldwide and are among the most affordable pets. With all the above tidbits, you are hopefully now well-placed to get a pacu pet fish.

Written by Fabian

Hey, I'm Fabian, chief editor at Aquarium Nexus. I really enjoy the aquarium hobby and love sharing my experience with others. If you have any questions feel free to contact me or leave a comment below.

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