Corydoras pygmaeus colony breeding, surprise!

[Byron]

Do you have a rough suggestion for how many adult pygmies this tank can support? I had thought about 12, but it's easily handling this 23 or so right now, only needing a WC once a week - it could go fortnightly or more without nitrates rising above 20ppm, but I've never tried leaving it longer. Obviously the cories like to be in as large a group as possible. Should I be guided by how stable the tank remains and how crowded it looks? I don't think I'd want more than 22 or so in there (not counting fry/small babies), but since it's working still at this stocking level (and I'm on top of plants/filtration/water changes 1-2 times a week), would I be overstocking it?

That would be a stocking level of;
8 guppies
3 otocinclus
22 adult pygmies plus fry and sub-adults until old enough to rehome.

In a 'normal' 60 litre/15.5 g, I'd consider that well-stocked, but perhaps a tad overstocked?

I assume the tank dimensions are 24 inches (60 cm) length, and 12 inches (30 cm) width, i.e., a standard 15 gallon.

You have no issues with the cories. I acquired six several years back, and after their time in the QT I couldn't decide on which tank to put them in, and I had new fish expected for the QT. So I put them in the 10g that had been running for a few years, but at the time had no fish. In a few months, eggs appeared, not a lot, but here and there. Then fry appeared. This went on for a few months, and one day I counted 32 cories, they were all together motionless mid-water and I was able to accurately count them. When I moved two years ago, I decided to put the seven grown "fry" that were left in the 29g "blackwater" tank I set up at that time. There have been obvious signs of pre-spawning behaviour (males crowded around a chunky female), but so far no eggs/fry. But given the other fish in this tank, I don't expect any eggs to survive predation.

So you have lots of space. With the guppies and otos, likely not many eggs will escape, if that is a hope.

 

[ClownLurch]

If it ain’t broke don’t fix it.
If things start to change you can always move your guppies elsewhere to buy time. I’d imagine their bio load is way bigger than a similar number of Pygmy Corys.

 

[AdoraBelle Dearheart]

And why the heck isn't this in TOTM?! 3 slots/ 1 day left to enter...

You convinced me, just added my entry

Thank you so much everyone for the feedback! It helps so much, and has reassured me! Love these sweet little fish so much, everyone should have them! lol.

Sticking with "if it ain't broke, don't fix it!" while I will have to move the tank soon(ish) to make space for the 57g, I'll preserve this one as it is, with the mixed substrate. I do want to add some more sand once it's moved, so it's slightly deeper and covers more of the footprint, but that's easy enough to do.

Oh and if anyone local is looking for a batch of young pygmy cories, message me and we can make a deal, lol

Will respond more to these replies tomorrow, thank you again!

 

[itiwhetu]

Why do you think these fry have survived??. Think about where you find them and where they go when spooked. That is your answer to what you should do with your tank setup.

 

[AdoraBelle Dearheart]

Why do you think these fry have survived??. Think about where you find them and where they go when spooked. That is your answer to what you should do with your tank setup.

Thanks for responding with your thoughts

As I've said, I'm still a beginner to the hobby really, only two years in, and the livebearers were the only fish I bought with the intention of breeding - cory breeding (both bronze and pygmy) was an unexpected yet welcome surprise to me!

As for why I think they've survived, my guess is dense planting, lots of ground cover, and lots of micro organisms for them to feed on, along with the fact I feed things like Bug Bites and daphnia to the adult fish which are also small sized foods that they fry can eat. That's my hypothesis, but I'm not 100% sure of this, which is why I'm seeking opinions from people smarter and more experienced than I!

Where the fry go when spooked - they don't only bury themselves in the gravel. They dart away under almond leaves, hide in the bases of plants (the crypts and vallis are where I often find them), under the slate cave, and yes, I've also seen tiny ones push themselves down into the gravel when I'm cleaning the substrate. Personally I'd prefer that they hide in the leaf litter and live plants when spooked, since it looks painful when they push down into the gravel and I worry they could hurt themselves. But they will do it if they get into that panicky state cories sometimes reach.

I do think that the gravel collecting mulm might be helping in terms of producing mulm, and hence, micro-organisms. But so does the leaf litter/almond leaves etc. I add a lot more botanicals like those to this particular tank, because it's my only softer water tank and I know otos and pygmies like to graze on the biofilm and tiny critters that are working away, breaking down the organic material. I haven't yet experimented, but I wonder whether I would see more seed shrimp and tiny critters like that in a sand only tank if it also had a lot more leaf litter. What is helping more, the gravel or the bontanicals, you know? Perhaps having both is beneficial, but is it essential? I don't know the answers to either of these questions, but I'd love to learn more!

Also seriously considering trying a similar set up in my other 60 litre tank and trying to colony breed habrosus as well as the pygmies! I'm emptying, tearing down and rebuilding a 57g tank too, and haven't chosen a new substrate for that one yet, so I'm bearing all of those in mind when asking these questions.

ETA: Just had another thought. This is the only tank I have where I also add rainwater I collect. The others are tap water only. The rainwater is bound to be introducing tiny critters too, I wonder if that plays a part?

 

[Byron]

The rainwater is more likely a question of better parameters. And you don't need a conditioner with rainwater unless you are mixing in tap water. As for the fry surviving, the more chunks of wood with moss and the thicker the plants, the more change the eggs have of being laid where they will not be found and eaten, and that is key. When they hatch, the fry are obviously better able to survive predation. But their food is, as you surmise, the microorganisms in the plants and on the wood. The older the tank setup the better. Dried leaves like oak, beech, maple, almond also really help as these produce a lot of infusoria and the fry will grow faster and stronger with these present.

 

[AdoraBelle Dearheart]

The rainwater is more likely a question of better parameters. And you don't need a conditioner with rainwater unless you are mixing in tap water.

Oh for sure, I use mix of rain and tap water, purely to lower the GH and KH of my tap, since the tapwater is too hard for the otos and pygmies on its own, and because RO is expensive and confusing! I have a pretty good system of water barrels here to collect rainwater, so I take advantage of them Only use declorinator for the tap water amount I use

I just wondered whether the collected rainwater also introduces some micro-critters into that tank, which aren't found in my tapwater only tanks, just since we were on the topic! I don't object to free fish food, and the water barrels have covered tops, so never found anything nasty or risky in there.

As for the fry surviving, the more chunks of wood with moss and the thicker the plants, the more change the eggs have of being laid where they will not be found and eaten, and that is key. When they hatch, the fry are obviously better able to survive predation. But their food is, as you surmise, the microorganisms in the plants and on the wood. The older the tank setup the better. Dried leaves like oak, beech, maple, almond also really help as these produce a lot of infusoria and the fry will grow faster and stronger with these present.

The only risk to the eggs in this tank are the guppies I think. Otos almost exclusively algae and biofilm eaters, and pygmies don't eat their eggs or fry the way the larger cories are prone to do, in their bumbling, scavenger way! The pygmies also tend to lay their eggs on plant leaves rather than the glass, and with plenty of vallis and crypts, that's a lot of leaves - even the hungriest guppy isn't likely to find all of 'em if it tried!

The guppies are also only a temporary tankmate. I'm keeping these as I'm attached to them, but as they pass away, I won't be replacing them (no matter how tempted I may be!). They might get moved to another tank at some point, not sure yet, but either way, once the guppies are gone, I plan to gradually adjust the GH back down so it's 3/4s rainwater and 1/4 tap, then get some nano schooling fish to live with the pygmies and otos. Ember tetra, kubotai, celestial pearls - something like that. Haven't chosen a species yet, but I'd really love some kubotai rasbora. Stunning little fish that would suit the tank I think!

 

[Byron]

That's fine, just remember you will not see many (if any) cory fry with any of those fish in the tank.

 

[AdoraBelle Dearheart]

That's fine, just remember you will not see many (if any) cory fry with any of those fish in the tank.

Oh no! I don't want that

I want to keep it as a pygmy cory breeding set up, but I feel like the guppies act almost like a dither fish. The way they swim about in the open seems to reassure the otos and cories that it's safe to come play in the open, and they add some nice colour to the top/mid area of the tank.

Are there any other fish you think might work in this set up that won't predate too many of the eggs/fry? If not, I might well stick with male guppies or endlers.

 

[Ch4rlie]

Are there any other fish you think might work in this set up that won't predate too many of the eggs/fry? If not, I might well stick with male guppies or endlers.

Nano fish species come to mind as they have smaller mouths and less greedy than guppies imo but most fish species regard any eggs in the tank as food nonetheless really.

By the way you mentioned salt & pepper corys (habrosus) in an earlier post, those ARE my absolute top favourite cory and pygmys a close second place, the only reason I prefer habrosus is that they display more natural cory behaviors when in a good sized group than the pygmys, also habosus are cuter imho

If you happen to set up a breeding tank journal for habrosus in the future, I'd be watching that thread REALLY closely

 

[Byron]

Oh no! I don't want that

I want to keep it as a pygmy cory breeding set up, but I feel like the guppies act almost like a dither fish. The way they swim about in the open seems to reassure the otos and cories that it's safe to come play in the open, and they add some nice colour to the top/mid area of the tank.

Are there any other fish you think might work in this set up that won't predate too many of the eggs/fry? If not, I might well stick with male guppies or endlers.

About the only fish that would not likely find and eat the eggs would be surface fish like hatchetfish. The smaller species in the genus Carnegiella only, not the larger in Gasteropelecus and Thoracocharax. Any fish that is mid-tank or lower is bound to find eggs unless they are really well placed.

 

[Byron]

On the pygmy and habrosus cories, do not keep these together in the same tank. I did this once, and I am not sure why but it just didn't quite work.

 

[AdoraBelle Dearheart]

Have been trying to get some decent photos of the smaller babies, but it's tricky! Will keep trying

In the meantime, photo dump of the shots I already have!

I call this one "Conference on the Almond Leaf, Oto as Guest Speaker

Swimming with one of my favourite guppies, Red;

Ooohh this one, you can see Larry in the bottom right corner, looking suspiciously like she's carrying eggs again. I can always tell her apart because as well as being a large female, she's more of a brown shade, while the other adults are more silver/grey. Have no idea why, but since they were bought months apart from each other, perhaps they were caught/bred from stock that were collected from difference areas? Just a guess though. She seems healthy, and I'm now seeing more youngers with the brown-ish shade to them, so probably her babies.

The female who is vertical and showing her belly to camera also seems a bit chunky! More fry on the way for sure.

How many pygmies can you count? Love when I just spot a little nose peeking out!

 

[AdoraBelle Dearheart]

Nano fish species come to mind as they have smaller mouths and less greedy than guppies imo but most fish species regard any eggs in the tank as food nonetheless really.

By the way you mentioned salt & pepper corys (habrosus) in an earlier post, those ARE my absolute top favourite cory and pygmys a close second place, the only reason I prefer habrosus is that they display more natural cory behaviors when in a good sized group than the pygmys, also habosus are cuter imho

If you happen to set up a breeding tank journal for habrosus in the future, I'd be watching that thread REALLY closely

Habrosus are adorable! I can't pick a favourite until I've kept them all But I was torn between pygmaeus and habrosus when I was contemplating having some, then wound up with pygmies because I impulse bought Larry as a singleton at the store. So pygmies it was! I'm not unhappy about it at all, I really enjoy that their behaviour is different from a 'typical' cory. It's like they're a cross between a cory and a mid-water swimming tetra or guppy or something

I'll fight you on the idea that habrosus are cuter! Wook at my pygmies wikkle faces! Those big dark eyes and tiny noses are hard to beat...

Will definitely make a journal thread for the tank that might turn into an habrosus tank, so I'll make sure to tag you when I get some! I definitely want to get some and try to get them breeding in this way too. It'll just be a while before I'm set up and ready for them

Speaking of journal threads though, would it be okay to move this to a journal section please? I should have started it there, but wanted to get advice first. Would planted or freshwater be better?

 

[Lajos_Detari]

I guess I am late... LOL

Short answer:
My priority is always "fish over plants". Fish first and plants second.
So, as long as you "like" the look of your tanks and there is no issue with your fish, then the tank should be fine.
It will require more work if you really want the plants to thrive in your tank.

Long answer:
Nevertheless, if you really have a lot of time and you really want to build a very nice planted tank, you can take a look at this ADA website below.

It will require soil in your tank or soil at the bottom layer and sand at the top layer.
But probably you cannot have fish like Corydoras that will dig into the sand/soil.
Also, the problem with soil is you may have to replace them after a few years.

Nature Aquarium Starting from Zero | ADA - NATURE AQUARIUM

ADA designs and develops products of aquarium, lighting and CO2 supply system to propose Nature Aquarium where tropical fish swimming in densely grown aquatic plants.

www.adana.co.jp

But for my own tanks, I only have simple planted tanks as I don't have much time to take care of the plants.
So, my tanks only have floating plants, tall driftwoods and some rocks.
I took only a few hours to set up a new tank(excluding the hours in rinsing the sands and sterilizing the driftwoods and sterilizing+ quarantining the plants).
I tried to create a "biotope or a jungle look" for the fish to feel secure and comfortable.
My favourite plants are Java Moss, Anacharis Elodea, Cabombas and Hornworts.

I find that biotope style of tanks look very natural and very relaxing..
It's like having a small stream or river in your house....
You can consider this kind of tank if you want an easy to maintain tank.

Here are some information about biotope and how to create them.
There are many videos of different biotopes from different countries and continents where you can get some ideas.


Biotope info:

Index of /info/

Videos of biotopes from different countries and continents:

Videos • Biotope Aquarium

biotope-aquarium.info

Here is another website on expeditions to South America:

Welcome to Toms Homepage

Lastly, I attached some photos of aquariums from a LFS here.
They used mainly soil plus CO2 injection.