They are a large freshwater fish with a mouth full of tiny teeth! They will eat anything that looks edible! Heck, they will chew on many things that aren't edible, including gravel and power head wires! Watch your hands when you clean these fish's tank! They might bite you! Sounds like a piranha, right?! Well, almost. Unlike the piranha, this fish is extremely timid! Meet one of my personal favorite fish: the cowardly cousin of the piranha, the Red Bellied Pacu!
Red Bellied Pacu
I have to admit that the first time I saw the red bellied pacu for sale, I really thought it was a piranha! In addition to having sharks for my freshwater aquariums, I had also always wanted some piranhas as well! (And what full blooded American boy wouldn't?!) So from the moment I first saw these "piranhas", I decided that I would get some of those for my freshwater aquariums, too!

Once I found out that these fish weren't actually piranhas, and instead they were called "pacus", that didn't diminish my urge to acquire some of these menacing looking fish. Truthfully, the red bellied pacus do look like piranhas. Their bodies are dark gray with scales so tiny that it appears they actually have "skin" like a catfish. Their bellies and anal fins are red, hence their name. As the red bellied pacu gets older, their red coloring tends to fade. The red bellied pacu is a deep bodied fish, with a rounded head. If you can catch a red bellied pacu still long enough to investigate it, you will notice the fish has a mouth full of tiny, sharp looking teeth. Sounds just like a piranha, right?

The pacus and piranhas are actually cousins. Both fish are part of the Characin family. In most cases, they can pass for twins until it comes to their behavior. While the piranha is in most cases an aggressive, hunter fish, the pacu is a big coward. They are very timid, and easily frightened! Of all of the freshwater fish that we have, our pacus are probably the most timid. They are more jittery than our red finned cigar sharks and our iridescent sharks! However, unlike the sharks, when the pacus get frightened it could spell trouble for their tank! And everything frightens them: feeding time, turning on or turning off their tank's light, or just walking within seeing distance of them!

One thing you will notice quickly about the red bellied pacu is how fast it grows. We bought 6 red bellied pacus that were roughly the size of a half dollar at Christmas two years ago. Six months later those pacus were anywhere from 6 inches long to almost a foot in length! When you get a group of fish that size in a tank together and they become frightened, look out!

The pacus possess powerful speed, which they display when they become frightened. Anything that gets in their way will pay the price. We have had to replace two glass heaters so far. The pacus crash into the heater, which will then crash into the aquarium wall and break the heater! We have tried bracing the heater with metal clamps attached to the wall of the aquarium with a suction cup. The pacus find these clamps and discover that they can remove them and then chew up the suction cup!

Another problem pacus present when they become frightened is a free bath for the surrounding area! We try not to keep our pacus' tank completely filled up because the pacus will splash the water out every time they are scared. We have had wallpaper begin to peel because the pacus splashed water out of the back of the aquarium. Our Boston terrier, Roscoe, has a food and water dish next to the pacu tank. Needless to say, Roscoe's water dish is never completely empty, although I'm sure he doesn't appreciate drinking pacu water!

Probably the most dangerous problem we encountered with our pacus was with a power head. While cleaning their tank, my wife noticed the water had a "tingle" to it. It was kind of like a small electrical charge running through the water! After looking for the source of this "tingle", we discovered that the pacus had chewed the covering off of the thick wire running into their power head. The wire was exposed, and if the pacus decided to take another bite on the wire, we would have had a pacu fish fry!

If you are planning on setting up a tank for some pacus, keep in mind that you won't need to use many tank decorations at all. If you do, these will probably end up destroyed when the pacus get frightened. Due to their imminent growth, you should try to place your pacus in a tank that's at least five feet long and two feet wide. One or two pacus will do fine in a 55 gallon tank, but if you decide to get a school of pacus, put money back for a 100 to 200 gallon tank!

If you decide to pair up pacus, it may be a little difficult to determine the fish's sex until the pacu matures. At that time, the male pacu will have a redder stomach area and a more pointed dorsal fin than the female.

The red bellied pacu tank will need at least inch of aquarium gravel in it. As a treat for the pacus, consider dropping in a few of the larger colored aquarium rocks. We dropped some of those large, fake, green, transparent rocks into our pacu tank. For some reason, the pacus fight over these rocks! We have spent hours watching our pacus grab these rocks in their mouths, then fend of the other pacus who obviously think it's food! They don't eat the rocks, they just chew on them. We pulled one rock out, only to find dozens of tiny teeth indentions all over it! If you decide to give the tank a natural look, you may want to use plastic plants. The pacus will eat the live plants. In fact, the pacus will eventually chew up the plastic plants, but they will last longer than the real ones!

One great thing about the red bellied pacus is their hardiness. The pacu may very well be the hardiest fish I have ever come into contact with. Our pacus have never had a single illness, even though they can get ich. Since they are so hardy, the pacus will live for a long time. Keep in mind that since they live for a long time, they will also grow larger than you probably would want. Red bellied pacus can grow anywhere from 12 inches long to over two feet long, although a foot long pacu is typical for the home aquarium! In fact, there is another pacu that actually grows larger. The Black Pacu can easily reach a length of 30 inches or more! Nearly every year there is a report somewhere of a fisherman catching one of these 2 foot long "piranhas" in a lake somewhere, apparently after a hobbyist realized their pacu was too big and decided to "set it free!"

The pacus are able to withstand a wide variety of water conditions, even though you should do your best to set their tank up to reflect their natural habitat of the Amazon basin. The pacu can handle a pH anywhere from 5.8 to 7.5, even though a neutral pH is preferred. They will also tolerate a water temperature anywhere from 72 to 82 degrees.

Feeding a pacu is simple. If you drop something in their tank, they will eat it! When I first purchased my red bellied pacus, I was told that they were "vegetarian piranhas." This is not true! These fish are clearly omnivorous. They prefer plant food, but they will eat meat as well. I started out feeding our pacus flake foods, which they still love. Then they started eating cichlid pellets and shrimp pellets. Since then, my three year old son has shown us that the pacus will eat hamburgers and hot dogs! Pacus also enjoy more conventional foods such as grapes, peas, live foods and even cherry tomatoes! In the wild, pacus prefer hard nut-like vegetation that they crush in their powerful mouths. And we have never worried about food waste accumulating in our pacu tank. Food rarely lasts long enough to hit the bottom! Our pacu tank is usually the cleanest tank in the house!

You may discover that pacus deserve their own species aquarium. I have tried to keep pacus with numerous fish unsuccessfully. While they were young, I kept the red bellied pacus with oscars. Once they grew up, the oscars' tails and fins became nipping targets. I then placed the pacus into their own tank, and let them share space with a red devil. The red devil was king of the tank for about 6 months. Then one day, apparently the pacus decided to overthrow the king! I found the red devil that morning missing most of it's tail and dorsal fin!

The only fish that I have kept successfully with the red bellied pacus are few and far between. I kept a medium sized peacock eel with them for awhile. The eel apparently was so scared of the pacus that it never came out of hiding. We honestly thought the pacus had eaten the eel for about three months until we found it hiding in a small decoration during a tank cleaning.

My pacus currently share a tank with a half dozen silver dollars. These fish get along mainly because they are both Characins. (Essentially, another kissing cousin!) Also the pacus share tank space with two plecos. Despite an occasional fin or tail nip, the pacus get along fine with the plecos, too. The only problems we have within this tank is the pacus fighting amongst themselves. It's not unusual to see a couple of pacus with a nipped fin or tail.

You should be able to find a red bellied pacu at nearly any pet store. The red bellied pacu may also be sold under the name red pacu or simply pacu. These fish have been readily available for years in the freshwater hobby since Brazil set up a fish farm to spawn and release them. This fish farm was successful and the red bellied pacus spread to many other fish farms across the world. Now they are being raised in huge fish farms throughout the world as a food fish! A plus to their abundance is that most red bellied pacus are very affordable. In most cases they will run anywhere from $4.00 to $7.00 when they are small. The only drawback to their abundance is the fact that other pacus, such as the black pacu, are now nearly impossible to find.

If you've got the money to invest in a large aquarium, consider the red bellied pacu. This fish is one of the hardiest fish in the hobby. It is long lived, and very lively! The red bellied pacu is easily fed. In fact, it would probably even eat table scraps if your garbage disposal quit working! Oh, and you may also want to invest in some heavy duty gloves, as well! Cleaning a pacu tank might interest the pacus in some "finger food!"
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