Hoplo Catfish – Species Profile & Facts

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The hoplo catfish is the closest you can get to a prehistoric fish species with a unique appearance and extremely high adaptability.

While this species isn’t as popular in the aquarium trade, its name gets thrown around more often for a variety of reasons.

These include:

  • Ease of keep
  • Adaptability to a variety of water conditions
  • Interesting physical appearance
  • Overall temperament and personality

Today, we’ll discuss the hoplo catfish to find out what makes it unique and why you might want to get one.

What is a Hoplo Catfish?

The hoplo catfish belongs to the Callichthyidae family and ranks as a resilient and peaceful tank companion.

This alone is rather rare in catfish, given that these fish can get territorial and exhibit bullying behavior towards their tankmates.

The hoplo inhabits areas in North and South America, primarily the Amazon, numerous rivers in North Brazil, the Orinoco River basin, and plenty of other areas.

The fish’s habitat is unique in that it varies in terms of water quality and even salinity. This is primarily a freshwater species, but you can also find it in brackish water in the wild.

One of the most noticeable characteristics on display is the catfish’s armored plates. These cover the fish’s entire body as part of a defense mechanism against predators.

The hoplo also uses its dark and spotted color pattern to blend in its environment and lower its detectability.

Hoplo Catfish Requirements

While the fish ranks as hardy and adaptable, you still need to ensure optimal living conditions to improve its health and prolong its life.

Fortunately, the hoplo catfish doesn’t ask for much.

The basics include:

Tank Size & Setup

While many people recommend 20-30 gallons of water for a hoplo catfish, I say 50 gallons are even better.

That’s because the hoplo catfish isn’t like other catfish species. While this fish also keeps a low profile, spending most of its time near the substrate, it will also swim to the water’s surface quite often.

The hoplo does that for breathing purposes, as this is one of the few fish species that rank as intestinal breathers.

The fish uses its gills to breathe normally, like any other fish. But it also displays the ability to breathe through its intestine, which isn’t something you hear very often.

This places the fish in the category of GAB (Gut Air Breathing) fish. In short, the fish’s intestinal wall is thinner, allowing for capillaries to penetrate into the luminal epithelium for improved vascularization in the area.

The fish can use this feature to exchange gases via its intestinal wall, effectively absorbing oxygen from the atmosphere.

This feature is similar to that of labyrinth fish that use their specialized organ to survive in hypoxic (low-oxygen) waters. The fish’s GAB ability has the same goal.

So, the fish needs to go up and down the tank frequently to breathe at the water’s surface. Hoplo catfishes are also more energetic than other catfish species, which is why they can always use additional swimming space.

Regarding the overall setup, go for live plants and gravel, pebble-based substrate. Caves and rocky formations are necessary, given that the fish is nocturnal, so it needs hiding areas during the day.

In the case of live plants, aim for anubias, cryptocoryne, or any other species with strong root systems. These fish are known as diggers, so they may unearth or damage more sensitive plant species.

Water Requirements

The basic water requirements include:

  • Temperature – 72-86 °F
  • pH – 5.8-7.5
  • Water hardness – 20 dGH max

These standard requirements apply to most tropical fish within certain limitations. Preserving water quality is important, despite the hoplo catfish’s ability to thrive even in poorly-oxygenated environments. Have a good filtration system available and ease the fish’s access to the water surface.

The hoplo catfish will swim to the surface to breathe atmospheric air no matter how well-oxygenated the water is.

Outside the filter, basic tank maintenance is required to preserve the system’s stability, but you don’t need to go overboard.

This is a hardy and resilient species that doesn’t need impeccable water conditions; one of the reasons why it’s perfect for beginners.

Feeding and Diet

The hoplo catfish is omnivorous and will eat whatever it can find in its environment. The fish makes for a fine addition to a community tank for this reason, as it consumes the food leftovers from other fish.

While the hoplo catfish doesn’t require feeding as often, it still requires additional sustenance to remain healthy in the long run.

Provide your catfish with a good omnivorous diet involving sinking pellets and some occasional greens, but don’t go overboard with it.

The hoplo catfish won’t require more than a meal per day, especially if it lives in a rich community setup. It will have a lot of food leftovers to munch on.

Do Hoplo Catfish Need a Heater?

Yes, a heater is absolutely necessary for a hoplo catfish. This species prefers higher-than-usual temperatures, generally between mid-70s and low-80s.

The heating unit will keep temperatures stable to prevent excessive fluctuations between day and night.

Do Hoplo Catfish Need a Filter?

Yes, I recommend getting a filter for your hoplo tank. The catfish may seem like it doesn’t need a filtration system, seeing the conditions it endures in the wild, but that’s not quite true.

While this catfish is extremely adaptable and resilient, it can still get sick in improper water conditions.

The filtration unit is that much more necessary in a community setup where you have a lot of fish-produced waste and food residues.

The hoplo catfish will participate in the cleaning process, but you shouldn’t rely on the fish to keep the environment stable.

A reliable filter will oxygenate the water properly, remove dirt and dead organic matter, and keep the water clean and clear.

Just make sure to tweak the filter’s power accordingly to prevent excessive water currents.

How Much do Hoplo Catfish Cost?

A typical hoplo catfish juvenile can reach prices of $10-$20 with some variations depending on the seller, the fish’s pedigree, etc.

You want to get your hoplo catfishes from reputed and reliable sellers to eliminate the risk of acquiring an old or sick specimen.

This means staying away from regular fish shops, especially since few of them specialize in catfish care.

Reputed fish keepers are better choices, given that their entire specialty revolves around growing, breeding, and selling fish as a job.

What is the Lifespan of Hoplo Catfish?

This is another area where the hoplo catfish is different from most fish species. While most fish live more in the wild compared to captivity, the hoplo catfish lives more in captivity than in its natural setup.

Hoplo catfishes live up to 6 years in the wild but can reach 10 or more years in captivity.

This is proof that it pays off to keep the fish in pristine water conditions, despite its hardiness and adaptability.

How Big do Hoplo Catfish Get?

The hoplo catfish can grow up to 7 inches, although most specimens will settle for 5-6.

Again, provide the fish with ideal living conditions, and you will both increase its lifespan and boost its overall size with time.

Are Hoplo Catfish Aggressive?

The hoplo catfish is a more balanced type of catfish in the sense that it’s both a sword and a shield.

This catfish is designed by Mother Nature to withstand most attacks and bullying from other fish thanks to their plated armor. But the fish can also snap at their attackers should the situation require it.

While the hoplo catfish is generally peaceful, it can produce violence in some scenarios.

These include:

  • Food and territorial competition – You shouldn’t house your hoplo catfish with other bottom feeders. The catfish won’t like the intruders feeding on their food and violating their personal space and territory. Scuffles are bound to happen in this case.
  • Spawning-related aggression – Hoplo males are notoriously violent during the spawning phase. They will protect their right to mate and often get into fights with other males and even other fish. Hormones run rampant during the mating phase, so it’s natural for spirits to be more volcanic.
  • Overcrowding – Overcrowding is always an excuse for violence among fish. Most of the battles take place on grounds of territorial disputes but can also result from the pure stress of overstocking. Make sure your fish have sufficient space to prevent such unfortunate interactions.

Hoplo Catfish Tankmates

Fortunately, the hoplo catfish is overwhelmingly peaceful, docile, and welcoming of other tankmates. It just comes down to finding compatible tankmates for them.

Avoid overly aggressive and territorial species that may bully the catfish. The aggressor won’t be able to hurt the catfish due to its shielded body, but the constant stress and pressure aren’t ideal.

Also, skip other types of bottom-feeders, as we’ve already discussed.

Some of the ideal tankmates for hoplo catfishes include bettas, cherry barb, tetras, guppies, Kuhli loach, and even African cichlids.

The latter makes for a curious case, given that few fish species can adapt to an African cichlid environment. Cichlids are notoriously aggressive and territorial fish that don’t like to share their space with anyone.

Fortunately, the hoplo catfish won’t mind the cichlids’ fiery temperament since they can’t hurt them.

Eventually, the cichlids will lose interest in the catfish, allowing both species to cohabitate in peace.

Always monitor your fish’s interactions and dynamics to ensure they don’t step out of line.

Also, consider keeping several hoplo catfishes since these are schooling fish. They can live alone, but it’s less than ideal for them.

These are social fish that enjoy living in a hierarchy-based group; it keeps them calmer, happier, and more energetic and engaged over the years.

Just don’t have more than 1 hoplo male per tank. Hoplo catfish males are notoriously violent towards one another, especially during the mating phase.

It’s not uncommon for them to kill each other over females, food, territory, and even hierarchical dominance.

Are Hoplo Catfish Good for Beginners?

Absolutely, they are. Hoplo catfish are great for beginners, given their hardiness, easy-going attitude, low maintenance demands, and community-compatible profile.

They can overlook any mistakes that you’re bound to be making as a novice aquarist, thanks to their adaptable nature.

You only need to provide them with stable water conditions, adequate temperature, and compatible tankmates, and they won’t ask for much else.

Maybe some extra food occasionally to complement their diet.

How to Tell if Hoplo Catfish is Male or Female?

Fortunately, the hoplo catfish displays a clear dimorphism, but I recommend waiting until the fish is 8-10-months of age before sexing them.

This is to prevent mishaps that could result in housing 2 or more males in the same tank. We’ve already discussed the downfalls of that.

The main differences between hoplo males and females include:

  • Males are slightly smaller
  • Males have white abdomens that turn pinkish during the mating phase
  • Males have triangular and elongated pectoral fins, while those of females are rounder
  • Females have slightly larger and more prominent bellies, especially near the 10-month mark

Now that you know how to sex your hoplo catfish, can you breed them?

How do Hoplo Catfish Breed?

Hoplo catfish are bubble nesters, so you should provide them with the proper breeding conditions.

Don’t have too many floating plants that could prevent the fish from reaching the water surface with ease.

With this in mind, the mating-and-breeding process is quite straightforward.

You should be able to observe the following phases:

  • Nest building – The male will often take several days to build the nest since he likes to be thorough about it. It will use slime and even plant matter to create a stable and quite large nest, sufficient to take in all of the eggs.
  • Mating – After the nest is complete, the male will court the female to make its intentions known. Once the female accepts, it will swim to the surface, accompanied by the male, lay a batch of eggs in the nest, and then swim away. The male will fertilize them, then the female will return to deliver another batch. This means that the female is capable of producing hundreds of eggs during a spawning session.
  • Egg guarding – Once the eggs have been placed and fertilized, the male will chase the female away and guard the eggs religiously. The catfish’s parental instincts will kick in immediately, causing the male to attack any wandering fish or even catfish females coming too close to the nest.
  • The hatching – The incubation stage lasts approximately 2-4 days, depending on the environmental temperature. The resulting catfish fry will spend an additional 2-3 days in the nest, feeding on the egg yolk. After that is done, they will simply swim away in search of food.

Fortunately, hoplo catfish don’t attack their own eggs or fry, so the fry should be safe with the adults.

However, you should invest in a nursing tank if you have a community setup and worry about other fish attacking and hunting them.


The hoplo catfish is a unique animal both in appearance and in temperament and personality.

It’s hardy, easy to maintain, and can adapt to any community setup with some preparation. They’re also easy to breed, which makes them even more beloved among aquarists.

Just remember that hoplo catfish are schooling animals that like to live in groups.

So, be ready to get several of them and provide sufficient space, food, and a personalized aquatic layout for optimal results.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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