Origin: This Catfish was caught in the Amazon Rainforest in South America, and this catfish is also found in the Orinoco and Essequibo Basins to the north of the Amazon Basin.

Maximum Size: This Catfish can grow to be over 40" long, including their tails. Sometimes very old females are over 50" long.

Behaviors: these guys are usually active swimmers, and if there is food to be eaten they become very active looking for it.

They're aggressive only to other Redtail Cats or similar Catfish, but they will just swallow anything that fits into their mouths.

Compatibility: Some recommended tank mates include any fish that they cannot swallow.

Click here to read more about compatible groups of pet fish.

Temperature: they live well from about 70 to 80+ degrees F., but they're probably most comfortable at about 78 degrees F.

Click here to learn about aquarium temperature, aquarium thermometers, and aquarium heaters.

Feeding: Premium Pellet Food.

Click here to learn more about and shop online for premium fish foods.

Water Conditions: This Catfish seems to be tolerant of a wide range of water conditions.

Probably a pH of about 6.5 to 7.0 with moderate hardness is best.

Most water in the US has a higher pH and high hardness, but is seems to be OK, and so it's probably best NOT to adjust the pH or the hardness of the water.

Here in our facilities the water is hard and the pH is usually about 7.8. We ship them in this water.

Click here for a lot more information about aquarium water conditions.

Aquarium Size: It is probably best to house these fish in at least a 30-gallon tank, when they're less than 3" long, but a bigger aquarium is always better.

Allow at least 5-gallons of water for each Catfish under 3" long.

They'll eat a huge amount of food and grow very fast.

At about 3" they should be moved into a 40 to 60-gallon aquarium.

Eventually they'll need to live in a much-much bigger aquarium or pond. Say more than 1000-gallons.

SeaWorld of San Diego once had a large one in an aquarium that was said to have more than 10,000 gallons, and that aquarium did not look too big for that Catfish.

Decor: These Catfish do not need gravel, and a layer of gravel more than 1/4" thick will usually fill with bits of uneaten food that will contaminate the water.

Click here for more about aquarium gravel.

Live Plants: are beautiful and improve the water quality.

But these guys will bulldoze plants, as they look everywhere for food.

So they rarely have plants in their aquariums.

Aquarium Filter: Bio-Wheel Filters are highly recommended.

A Penguin 350B Filter in an aquarium with 30-gallons of water is OK to start with a few of these Catfish that are less than 3" long.

At 3" long they should be moved into a 40 to 60-gallon aquarium with a Penguin 350B, and soon they'll need a bigger aquarium with two or more Penguin 350B Filters along the back edge.

But eventually, when one grows to be 40" or bigger, it will need a gigantic aquarium with a gigantic filtering system.

Click here to learn more about aquarium filters.

The addition of Lava Rocks will keep nitrates in the ideal range.

Click here to learn more about using Lava Rocks in aquariums.

Life Span: these Catfish can live in excess of 20-years, provided they are fed premium food and kept in a very large aquarium with very fresh water.

Gender: as they mature females presumably become plumper than males.

Breeding: there have been no reports of spawning this catfish in an aquarium.

But they are now being raised by fish farmers for aquariums.

Popularity: this Catfish grows too big to be popular.

Names: The scientific name is Phractocephalus hemioliopterus.

Variations: So far as we know, there are no variations, but the Amazon and Orinoco Basins are very big and full of diversity, so it would not be a surprise, if someday some other variations are discovered.

We hope you've enjoyed reading these comments.

DrTom 03/05/2015