Pygmy Cory Care, Breeding, & Why You Need Them

I’ll be honest. I never liked owning corydoras.

But I say that so when I say, “Owning pygmy cories is amazing!” you’ll believe me. Seriously though, my pygmy tank has been my favorite tank of all time.

Not only are they so much cuter than they look in the pictures. And, let’s be honest, they already look pretty adorable.

But they’re also active, entertaining, easy to care for, and a breeze to breed. It’s impossible not to love these guys!

The pygmy cory (corydoras pygmaeus) is the smallest of all the corydoras species. Possibly the smallest catfish in the world.

It’s cousins, Corydoras hastatus and habrosus are also mistakenly called a pygmy cory.

Neither of them are pygmy cories. Though they are both smaller cory species. These cousins are more appropriately called dwarf cories.

So with that in mind, this article is only going to cover pygmy corydoras, not all three species.

Disclosure: we’re reader-supported! So if you buy a product I recommend, I might make some coffee money at no cost to you.

Table Of Contents

 

Distribution & Natural Habitat

Pygmy cories are endemic to Rio Madeira basin in Brazil. They’re usually seen along the banks or in surrounding flooded forest areas.

They enjoy hiding among tree roots and marginal vegetation in small tributaries, creeks, and pools that flow out from the basin.

The Maderia river is a sediment-rich white water river. Though it’s dark, it’s not blackwater.

Pygmies do best in lower light situations since they’re not exposed to a ton of light in the wild.

Aquarium Care

There are some big things – size aside – that set the pygmy apart from other cory cats. First off, they do a lot of swimming.

Most cories can be seen rooting around the bottom of the tank, but these guys go everywhere. And they do swim instead of scoot about on the bottom.

They’re also awesome at playing dead. It doesn’t seem to be intentional. They just rest… oddly. For extended periods of time.

The third – and my personal favorite – is that they don’t eat eggs or fry. So you can leave them all in the same tank to be one big, happy, colony!

I do wish they’d eat the infertile eggs though.

Tank Specs

A 10-gallon is the minimum I’d suggest. Though a 20-gallon long would be much better for them.

These are one of the few catfish that do use vertical and open space for swimming. So you’ll want to make sure you have plenty of swimming space for them.

And you definitely want a tight-fitting lid. Preferably with some air space between the lid and the water.

These guys will shoot up to the surface periodically to gulp air. And when they do they can launch themselves like tiny torpedoes.

So unless you want to want to come home to an empty tank….

You’re gonna want a lid.

One of the great things about the pygmy cory is that you can keep them at room temperature. As long as your house is comfortably warm, that is.

In fact, I would recommend you don’t get a heater unless you’re worried about drafts in the winter.

If you do opt for heater, make sure you grab one that’s adjustable. The programmed ones will get too hot for them.

Stocking

They have a light bioload and they are incredibly social. And it’s unbelievably sweet to see them all huddled up together resting!

It’d be hard to overstock these guys if you have a proper cycle, so load them up!

However, structure and swimming space are important. So it’d be wise to give them lots of nooks and crannies to explore as your numbers go up.

Plus entertaining for you!

Again, six is the absolute minimum I would do. And, honestly, you’re doing yourself an injustice by only having six.

They are so much more fun to watch in large groups and their behavior is more natural.

Every pygmy gets up to their own antics and they’re a never-ending delight to watch when you have a dozen or more. A dozen might sound like a lot of fish, but they’re like $2 per fish.

So buy them up and make the cost of shipping worth it! It’s worth not buying coffee for a week, isn’t it? (It is!)

 

Decor

In the wild, pygmy corydoras are found along the banks weaving in and out of root structures, marginal vegetation, and flooded forests.

They love tangled up roots, thick plants, leaf litter, seed pods, and all sorts of other fun things to explore.

For replicating roots, I find that spider wood works well. Plus it gives you plenty of opportunities to cut, chop, and glue it however you like.

If you’re an avid reader, you’ve definitely heard me mention Tannin Aquatics’ Sterculia Pods. Which has been a huge hit with my cory colony.

I always see at least eight in or huddled on top of it. Munching away, cuddling, resting. You know, catfish things.

Tannin also makes some awesome curated packs. One of my favorites for these guys is this Jau River pack from South America. It has all sorts of awesome flooded jungle vibes.

Again, I’m not affiliated with Tannin in any way, I just adore them endlessly.

Another big thing to note is that pygmy corydoras have barbels that can get damaged by sharp substrate or bacteria. For that reason I don’t suggest bare bottom.

HTH pool filter sand is great and I’ve never had an issue with it being too sharp or holding too much bacteria. Their barbels are as long and adorable as ever!

Plus HTH super cheap.

But I recommend you buy it in person because it’s not worth the shipping. But if you want to plant high-maintenance plants, sand isn’t going to cut it.

With these guys, it’s best to avoid substrates that are fine or powdery. They’ll just make a mess of it.

I included the best substrates below if that sounds like your situation.

Best Plants For Pygmy Cory

Pygmy cories do better with some plants. Carpeting plants are ones that I would avoid.

Carpeting plants require a ton of overhead light – which your pygmy cory won’t love. And they don’t let your pygmy cory root around in the sand like they naturally would.

If you’re looking to get the most natural and rewarding behavior, I suggest low light plants that can be grown in sand. And I happen to have a handy list of just those.

Because I got your back. Obviously.

Lighting & Filtration

These guys don’t do great with bright lights or high flow. They do, however, need good water circulation.

I find that a couple of air stones places around the tank on full blast mixed with a well-cycled sponge filter give them the optimal level of circulation without having to battle a raging current.

These little ones aren’t strong enough to put up with a torrent of water for long. But they do seem to enjoy playing in the bubbles from time to time.

I would be wary of canister filters, HOBs, or box filters because of the fry.

I’m sure the adults could handle it with some fine-tuning, but chances are pretty good you’ll end up with fry at some point if you have six of these little loves.

As far as lighting goes, they are much more at ease when their lighting is subdued. You can accomplish this through and adjustable light, tannins, or floating plants.

When they have bright lights on them, they tend to shoal up. Which is, again, a sign of stress and not a behavior you want to see all the time.

If you want suggestions on lights, filters, or air pumps, I’ve included my favorites below for you.

Water Care

Provided your tank is properly cycled, you can get away with relatively few water changes with these guys.

They’re not tolerant of ammonia, nitrites, or nitrates, but I’ve never had a problem with their bioload – despite feeding them tons of live foods.

Ideally, you want to change 10% of their water weekly. But you could definitely get away with changing 25% monthly.

If you add tannins to the water, I would lean closer towards the monthly schedule than the weekly one.

They don’t do super well when you change their water chemistry frequently, and changing their water weekly would likely send the pH all over the place. Of course, this is my experience with it.

Just something to think about and be aware of so you can work out what’s best for your particular situation.

The biggest concern with cories is the bacteria levels in the substrate. Be diligent about cleaning up leftovers, otherwise you may start to see barbel infections.

If you don’t know what to get for water care or meds, I’ve included a handy shopping list below.

Feeding

Feeding pygmies is a delight. They enjoy food – can’t say I blame them! – and are generally unpicky little creatures.

This makes them fantastic tank inhabitants!

But that doesn’t mean you should feed them just any food. In the wild, their diet would consist largely of microfoods. This would be tiny organisms that live in biofilm.

Foods like brine shrimp, vinegar eels, microworms, white worms, grindal worms, and daphnia are all readily eaten by them as well.

If you’re not into live food, I’ve also fed them freeze dried tubifex, freeze dried blackworms, frozen bloodworms, freeze dried or frozen mysis, golden pearls, and decapped brine shrimp eggs.

It is important to include some veggie foods in their diet. They are omnivores – though they do lean towards carnivore more.

Algae wafers are prepared foods like Repashy Soilent Green are great options for including greens.

On the topic of Repashy’s food, they also devour Spawn & Grow as well as Grub Pie. The only food I haven’t had success with are pellets. Even after they become soft and powdery, they’re not interested in eating it.

Still, these guys are the least picky fish I’ve ever owned.

For the whole list of foods and where to find it, I included a handy shopping cheat sheet below. 3 – 4 is probably sufficient for these guys, but more is always better.

Pygmy Cory Diseases

Here’s where pygmy cories lose a few points.

Most of them are wild caught, so it’s not their fault. If you happen to find captive-bred pygmies, you probably won’t run into as many issues.

But if you’re buying them, be aware that quite a few nasties can pop up over the course of the first few months and it’s super important to put them through a proper quarantine period.

Costia

Pygmy Cory Tank Mates

If these pygmies were larger, they’d make an ideal community fish. Unfortunately, due to their size, they can be harassed, intimidated, or even eaten by larger tank mates.

If you want to go for a community tank, you should look for peaceful additions that are roughly the same size.

A common suggestion is shrimp like cherries.

I would avoid these guys just because they both reside primarily at the bottom and one will almost always disturb the other. If you want to try it, there aren’t going to be territory wars. Just make sure no one is constantly disturbed or looks stressed out.

Your best bet would be adding boatloads of structure for them to perch on, hide under, and cling to. Guppy grass, driftwood, seed pods, leaf litter, and other structures will be your best friend.

This strategy should help minimize overlapping rest areas (like the bottom) where they’re highly likely to disturb each other.

Onto what I actually suggest.

I was so excited about putting this list together! I got to include so many squee-worthy fish and fish that I don’t get to include often. This isn’t a complete list, but I hope it inspires you to look into some other awesome and unusual choices for your aquarium.

Let’s get to some minis!

Breeding Pygmy Cory

Breeding pygmy corydoras is a snap. As long as you take care of them like I’ve outlined already, they’ll breed for you just fine. Of course, I’m not going to leave it there.

I’ll break everything down for you, but just know it doesn’t require any extra effort on your part in most cases.

To start, you’ll need more 1 female for every 1 – 2 males, though 2 is suggested. I know this sounds counter intuitive but, trust me, I’ve tried to not do it this way and failed horribly.

You can tell the difference between a male and female based on their size and shape. Females are larger and rounder. They look very femininly curvy, if you will.

Males are smaller and sleeker. Large males usually have a flat forehead that slopes down sharply to their mouth. Females tend to have more rounded heads.

You’ll need to feed them lots of high-quality foods to get them into spawning condition. The females will begin to look noticeably larger and plumper.

Once you see this, you’ll know they’re almost ready – or are ready – to breed.

Spawning

If they seem on the verge of spawning but aren’t thoroughly convinced yet, try a large 50% water change. Some people say cooler water than what’s in your aquarium, some people say with warmer…

I’ve found that either works.

What seems to be most important is that the temperature is different.

Once they start breeding, one male will chase a female who is ready to lay eggs. This usually prompts competition from another male (or even more then one) and they’ll all follow the female.

She’ll eventually pick a spot and a male and they’ll form a T-position. The male kinda looks like he’s sitting on her nose. She’ll carry a tiny egg between her pelvic fins and deposit it somewhere.

It’s tough to explain in words, so here’s a video for you.

Skip ahead to the 9-minute mark to see some breeding activity, or you can watch him walk through his whole breeding setup. If they’re in a species only tank, you won’t need another tank. They don’t predate on their fry or eggs.

From there, it’ll be left alone and it’ll hatch anywhere from 3 – 5 days.

Egg & Fry Care

Once the fry hatch, they are almost invisible little black dots. They’ll absorb their yolk sak for anywhere between 2 – 4 days.

Once they use up the nutrients in their yolk sak, they’ll start swimming around hunting for the tiniest food you can possibly imagine. If your tank was set up properly and fully mature, they should have no issue finding food.

If it wasn’t, you’ll want to start an infusoria culture before you embark on this process.

It’ll take them anywhere from 3 – 6 months to be fully grown and start spawning themselves. Around the one month mark, they’ll be able to eat whatever food you feed their parents.

I’ve found pygmy corydoras spawn almost constantly once they start as long as they’re happy and well fed.

The cycle seems to last about a week, at which point I do a 10% water change and they’re back at it. No one seems to be entirely sure just how many eggs they can lay, but I’ve counted 75 between three breeding females over the course of a week.

And that’s only counting the eggs I watched them lay.

Some sources suggest one female can lay as many as 50 eggs over the course of a week, but there doesn’t seem to be any official numbers.

Telling The Difference Between Dwarf Cory Species

Corydoras pygmaeus and Corydoras hastatus are the two that seem to gather the most confusion – likely due to their similarly tiny stature.

Pygmaeus has a black line that runs horizontally from their barbels to the caudal peduncle (the start of their tail.) Corydoras hastatus, on the other hand, has no line.

They have a little black diamond on their caudal peduncle and have shimmery green see-through skin.

Habrosus I’m, honestly, not sure how it gets confused.

Habrosus also has a black line, but their line isn’t straight and looks splotchy. The majority of their pattern is spotted or speckled. Pygmaeus has no speckling or spotting and their black line is almost pin-straight.

Further Reading & Resources

Seriously Fish

TFH Magazine

Science Direct