Amazon Leaffish

Amazon Leaffish – Care, Tank, Feeding

Monocirrhus polyanthus, otherwise known as the South American Leaffish or Amazon Leaffish, is an extraordinary fish to look at. Its broad, flat body is reminiscent of flounder, without the whole two eyes on one side of the head thing. They have long, protruding mouths with transparent fins.

Their bodies are marked randomly with spots or stripes and they range from yellow to light brown. Fortunately, they are not incredibly difficult to care for. They typically fall in the (moderate) care category as far as those things go. 

Care: How to Care For Amazon Leaffish

If you’re curious about the origins of the name, it’s because the leaffish looks like a leaf—a particularly dead leaf. Especially when one is very still in the water. An adult leaffish might max out at 4” but they are usually between 3” and 4”.


Leaffish aren’t very fond of really bright lights but that doesn’t mean they don’t like any light at all. As far as their habitat is concerned, keep the lights low and dim. Soft water is the way to go as well. In other words, mimic their natural environment to the best of your ability. 

Since not all fish like low light and soft water, that kind of limits the tank mates but it doesn’t eliminate all potential tank mates. However, if you want to put some tankmates in there with your leaffish, they need to be bigger and meaner than it is. 

Or, you can just have a bunch of leaffish in your tank. Anything smaller than it will be killed and eaten. 

Standard Length

The average length of an Amazon Leaffish is about 3.5”, but as we mentioned earlier, they can get up to 4”. Anything smaller than a Leaffish will be killed and eaten by that Leaffish, so be careful what you put in that tank with it. 

Aquarium Size

Amazon Leaffish isn’t very big as far as aquarium fish go. So you don’t need an enormous tank to take care of them, even if you have more than one. Depending on who you are talking to, the minimum tank size for Amazon Leaffish is 20 to 25 gallons. 

You may want to have a tank that is big enough to accommodate things that a Leaffish will find in its natural habitats, such as driftwood and floating plants or leaves. Leaffish like to hide in the wood and snag below the water.

So you might want to ensure that there is plenty of room in your tank to accommodate plenty of hiding spaces.

Aquarium Maintenance

The best substrate for an Amazon Leaffish is sand and that means taking good care of your filter since sand loves to clump up and clog the tubes and filter. Since you are going to be tossing driftwood and all manner of hiding places in there, you’re going to need to have a solid filtration system to keep the water clean and clear. 

If you are taking care of more than one Amazon Leaffish, you should consider something a little bigger than 25 gallons.

Water Conditions and Temperature

You should keep the pH in the water between 5.0 and 6.8 while the GH can be anywhere between 1 and 10. The water hardness (dH) should be between 2 and 5 and the overall temperature between 77°F and 82°F. 

You don’t want a strong current running through your tank. A Leaffish is not used to that. They are used to slow running water. So you’ll have to find a balance between an exceptional filtration system without a hard current in the tank.


Amazon Leaffish will eat anything that is smaller than them—anything that will fit into their mouths but nothing their own size or larger. It will only eat live food. If you drop a bunch of fish pellets in there, whether they float or drop straight to the ground, a Leaffish will ignore them. 

Fortunately, there are plenty of live options that you can feed them. 

  • Mosquito Larvae
  • Zebrafish
  • Bloodworms
  • Tubifex
  • Various Crustaceans
  • Platy
  • Guppies
  • Brine Shrimp

Basically, if it’s alive, swims around, and is smaller than your Leaffish, it’s fair game. An Amazon Leaffish will rapidly weaken if they go for too long without any food. You should feed them daily. Of course, that doesn’t mean dumping live fish into the aquarium every single day. 

Most of the things that you feed your Leaffish will likely swim around for quite a while before the Leaffish will get around to them. But it will when it’s hungry enough. 

Behavior and Compatibility

Amazon Leaffish are very friendly and happy fish. They generally get along with their fellow tank mates, so long as those tank mates are equal to or larger than the Leaffish. 

Anything smaller and the Leaffish is liable to eat it unless it happens to be a fiercely aggressive, fighting fish that punches well above its own weight. 

Are Amazon Leaffish Friendly and Peaceful? 

For the most part, they are. You can pack your tank to its limit with freshwater life and the Leaffish will get along just fine, so long as all of the fish in there are bigger than it is or they are also Leaffish. 

Besides, so long as your Leaffish has plenty to eat, it will happily stuff its face until it is nice and content. They do enjoy hiding inside and around thick vegetation, little caves, large chunks of driftwood, and things of that nature. 

They will also use these hiding spots to strike out against what it considers prey. If you want to maintain a friendly, happy Leaffish, then the best thing you can do is provide it with an environment that matches the environment it naturally lives in. 

All Things Considered

Amazon Leaffish are not too difficult to take care of, so long as you feed them and give them something that is closely related to the natural habitat they come from. They like soft water, moderate temperatures, and a habitat full of like size or larger creatures. Give them that, and they’ll be happy and healthy Leaffish.