Skittish Pygmy Cories?

Hi! I was just realizing I NEVER see my pygmy Cories. They stay in hiding and dart to the surface every once in a while. They barely move, they just sit there. The tank is 30 inches long, moderately planted. Tank mates are a bristlenose pleco, neon tetras, and honey gouramis. Usually the water parameters are great, but they just don’t move or do anything? I have been adding floating plants and have noticed a small amount of increased activity, but not much. Any thoughts?

From recent personal experience, try to see if the gouramis are bullying them. I know they're supposed to be ok for community tanks, and that both move in different sections of the tank, and you have a big enough tank.... but as I said from recent personal experience, I'd watch for bullying from the gouramis.

same with my corys. they just sit towards the back of the tank and rarely move.

outofwater said:

From recent personal experience, try to see if the gouramis are bullying them. I know they're supposed to be ok for community tanks, and that both move in different sections of the tank, and you have a big enough tank.... but as I said from recent personal experience, I'd watch for bullying from the gouramis.

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They don’t even glance at eachother the gourami stay up at the top picking about the duckeeed, the Cories just sit behind my sponge filter

@OliveFish05 Not related to this thread but do axolotl tanks need a lid?
Also, I love corydoras but snails are still better.

From your description, I would suggest there are a couple issues here that should be looked into. I have had Corydoras pygmaeus for many years in a 10g tank and they spawned many times; my current seven are fry that hatched in my tank about 4 or 5 years ago. When I moved almost three years ago, these were still in the 10g on their own (no other fish) and the tank had two chunks of wood covered with moss, and thick floating plants. I never saw them. After I moved, in June of 2020, I decided to move the seven into the 29g which was/is occupied by my remaining pencilfish, Ember Tetras and Green neon tetras. In only a couple of days, the cories became much more visible. They love joining the Embers and Green neons (none of whom are larger than the cories), chasing one another. But the cories also chill out together. The photo below is the group on one of their favourite resting spots, the sponge filter.

I would however be very concerned over the gourami here. C. pygmaeus is a small fish, and small fish are naturally more inclined to be skittish when it comes to their environment. A fish as large as the gourami might keep them "on their topes" more than is healthy, as this means stress. The floating plants will definitely help though, as they do not like overhead light. And give them lots of plants and branches and wood to browse; they will spend more time off the substrate than on it, much more than the larger species. You likely have sand, that is absolutely imperative with this species.

I don't know how many you have, but they need a good-sized group. I am considering acquiring 6 or more if I see some healthy ones, to add to my seven, as I am sure it would make quite a difference.

OliveFish05 said:

They don’t even glance at eachother the gourami stay up at the top picking about the duckeeed, the Cories just sit behind my sponge filter

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I wish the dwarf one is have was like that. He ate the entire floating canopy in 3 days flat, then starting coming down more often to nibble at the sinking wafers, that's when trouble started. Particularly one of the female bronze corys I have, not tiny by any means, was pale and just would go hiding anywhere she could whenever the gourami even seem to be on the approach.

As some other comment noted, the mere presence of a larger, or more aggressive fish might be enough to keep them away.

Good luck, hope things work out well for all your fish can't say I can offer any more advise or insight, unfortunately.

Byron said:

ftdrdxtrrrrrrrrrrrrrrrrrfgFrom your description, I would suggest there are a couple issues here that should be looked into. I have had Corydoras pygmaeus for many years in a 10g tank and they spawned many times; my current seven are fry that hatched in my tank about 4 or 5 years ago. When I moved almost three years ago, these were still in the 10g on their own (no other fish) and the tank had two chunks of wood covered with moss, and thick floating plants. I never saw them. After I moved, in June of 2020, I decided to move the seven into the 29g which was/is occupied by my remaining pencilfish, Ember Tetras and Green neon tetras. In only a couple of days, the cories became much more visible. They love joining the Embers and Green neons (none of whom are larger than the cories), chasing one another. But the cories also chill out together. The photo below is the group on one of their favourite resting spots, the sponge filter.

I would however be very concerned over the gourami here. C. pygmaeus is a small fish, and small fish are naturally more inclined to be skittish when it comes to their environment. A fish as large as the gourami might keep them "on their topes" more than is healthy, as this means stress. The floating plants will definitely help though, as they do not like overhead light. And give them lots of plants and branches and wood to browse; they will spend more time off the substrate than on it, much more than the larger species. You likely have sand, that is absolutely imperative with this species.

I don't know how many you have, but they need a good-sized group. I am considering acquiring 6 or more if I see some healthy ones, to add to my seven, as I am sure it would make quite a difference.

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Yours are gorgeous! Mine chill on the sponge filter occasionally... I have 11 of them in a moderately planted, sand bottom tank that has a large driftwood branch.

I got some more floating plants in the mail yesterday and they are out a lot more.

So you think just the presence of a larger fish is stressing them out?

OliveFish05 said:

Yours are gorgeous! Mine chill on the sponge filter occasionally... I have 11 of them in a moderately planted, sand bottom tank that has a large driftwood branch.

I got some more floating plants in the mail yesterday and they are out a lot more.

So you think just the presence of a larger fish is stressing them out?

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It seems logical that a fish that is five or six times larger than a pygmy cory might indeed give the cory a scare. If I were to sit in front of this tank for an hour to observe, it might confirm this, depending upon the interactions. I have never kept any of the dwarf cory species in tanks with fish larger than they are, and I think this is worth considering.

Remember there are the chemical signals between fish, pheromones and allomones, that have as much impact as physical interactions. We don't know what these signals may be since we cannot read them, but in most animals--a small dog for example will be much more intimidated by a dog three or four times larger than it would by another small dog approaching it.

Byron said:

It seems logical that a fish that is five or six times larger than a pygmy cory might indeed give the cory a scare. If I were to sit in front of this tank for an hour to observe, it might confirm this, depending upon the interactions. I have never kept any of the dwarf cory species in tanks with fish larger than they are, and I think this is worth considering.

Remember there are the chemical signals between fish, pheromones and allomones, that have as much impact as physical interactions. We don't know what these signals may be since we cannot read them, but in most animals--a small dog for example will be much more intimidated by a dog three or four times larger than it would by another small dog approaching it.

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Interesting. The honey gouramis are only about twice the size of the pygmy cories. I have noticed a huge difference since adding the floating plants. The pygmy cories all swam out the front of tank and picked at the flakes of food. This is the first time they've done that...

OliveFish05 said:

Interesting. The honey gouramis are only about twice the size of the pygmy cories. I have noticed a huge difference since adding the floating plants. The pygmy cories all swam out the front of tank and picked at the flakes of food. This is the first time they've done that...

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Good. This may be the solution then. If the respective fish have decided that there is no threat among themselves, then the obvious factors like the overhead light--which all forest fish like to avoid because it makes them vulnerable--seem more likely the issue.

They definitely like a jungle of plants, and things to explore! So I definitely recommend adding plenty of plants and other things they can perch on. That slate cave thing on the left side of my pygmy tank (doesn't have guppies in it now) is a favourite place for mine to sit on top of and chill as a group, and since I prop the top end up on the larger river pebbles, the tiny fry also like to hide underneath it. I imagine that as well as feeling safe and secure, it's also where mulm, and thus, micro-organisms gather.

They are a curious and playful little fish, so keep the tank interesting by adding small tettacotta pots, an interesting wood piece, some almond leaves, things like that.




Having said that, behind the sponge filter right at the back and deep into the plants back there is where mine all dive to if they're spooked, or I'm doing WCs etc. And they're easily spooked! Remember that the more there are, the more secure they feel, but also the more eyes are watching for any trouble! If one panics and dives for cover, the others will too. But mine usually calm and come out again pretty quickly, so I'd wonder too if they're nervous about the larger fish. Mine did used to swim with and follow the guppies at times, but I've never kept them with anything larger than that either. If adding more plant cover/visual tank interest doesn't work, perhaps trial the tank without the larger fish if that's possible (if you have a quarantine tank or something) and see whether that makes a difference in their behaviour?

Also, is the tank in a high traffic area perhaps? Mine is in a quiet corner, so as long as I sit a good distance away, or sneak up on them slowly so they don't spook too much, they come out and swim in the open water or feed on the beach again. Perhaps they are coming out to play when you're not seeing them, but spook and hide if you coming into the room startles them?

11 is a nice number of them to have, so that's a great start! Please do keep us updated, love these little fish so much! Hands down my favourite to watch, don't even know how many I have! Just know I started with seven, and there must be 30 or more in there now. They're constantly spawning, and I'm constantly finding new fry when I water change, or spotting a mini one joining the adults as they swim together. Gorgeous little fish!

AdoraBelle Dearheart said:

They are a curious and playful little fish, so keep the tank interesting by adding small tettacotta pots, an interesting wood piece, some almond leaves, things like that.

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I have a nice driftwood branch!

AdoraBelle Dearheart said:

Also, is the tank in a high traffic area perhaps? Mine is in a quiet corner, so as long as I sit a good distance away, or sneak up on them slowly so they don't spook too much, they come out and swim in the open water or feed on the beach again. Perhaps they are coming out to play when you're not seeing them, but spook and hide if you coming into the room startles them?

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It’s located in my bedroom. I am in there a few times throughout the day with my dog, but that’s it. While I’m in there I work on desk work, so I’m not doing anything crazy! Definitely not high traffic.

AdoraBelle Dearheart said:

11 is a nice number of them to have, so that's a great start! Please do keep us updated, love these little fish so much! Hands down my favourite to watch, don't even know how many I have! Just know I started with seven, and there must be 30 or more in there now. They're constantly spawning, and I'm constantly finding new fry when I water change, or spotting a mini one joining the adults as they swim together. Gorgeous little fish!

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I adore them. I wish I could breed mine, but I have a single C. hastatus and they can potentially interbreed, so...

AdoraBelle Dearheart said:

Having said that, behind the sponge filter right at the back and deep into the plants back there is where mine all dive to if they're spooked, or I'm doing WCs etc. And they're easily spooked! Remember that the more there are, the more secure they feel, but also the more eyes are watching for any trouble! If one panics and dives for cover, the others will too. But mine usually calm and come out again pretty quickly, so I'd wonder too if they're nervous about the larger fish. Mine did used to swim with and follow the guppies at times, but I've never kept them with anything larger than that either. If adding more plant cover/visual tank interest doesn't work, perhaps trial the tank without the larger fish if that's possible (if you have a quarantine tank or something) and see whether that makes a difference in their behaviour?

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My tank’s at a tough place right now and I would hate to disrupt the honey gourami more than they already have been or need to be. (It’s all explained in another thread...). I am not sure what to do with the honey gourami. I had 3, and am down to 2 (also In that other thread). I know they need a larger group, but I am not sure about getting more. I just don’t know what to do about it. I could sell them to my LFS or I could buy more. I hate to buy more if they really do stress the Cories, but I feel bad to rehome them...

OliveFish05 said:

I have a nice driftwood branch!

It’s located in my bedroom. I am in there a few times throughout the day with my dog, but that’s it. While I’m in there I work on desk work, so I’m not doing anything crazy! Definitely not high traffic.

I adore them. I wish I could breed mine, but I have a single C. hastatus and they can potentially interbreed, so...

My tank’s at a tough place right now and I would hate to disrupt the honey gourami more than they already have been or need to be. (It’s all explained in another thread...). I am not sure what to do with the honey gourami. I had 3, and am down to 2 (also In that other thread). I know they need a larger group, but I am not sure about getting more. I just don’t know what to do about it. I could sell them to my LFS or I could buy more. I hate to buy more if they really do stress the Cories, but I feel bad to rehome them...

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As far as I know gouramis in general, even dwarf ones, are territorial, and can live well without any company of the same species. Even pairing a male and female can have bad outcomes as they might square up instead of pair up. From what I've read so far gouramis are up there with bettas in the small buy feisty/territorial scale