Cory Still At Bottom Of Tank

[Benunited]

Hi folks

Getting a little worried - though probably shouldn't be. I'm a worrier when it comes to my fish.

I've had fish for a while but a few months ago started to introduce some corys: 2x juli corys and 2x pepper corys. Absolutely beautiful fish!

Tank is a 260 litre shared with 16 neon cardinals, 6 guppies, one plec, 2 frogs and a snail.

The worry I have is the recent change in behaviour of at least one of the julis. Only a couple of weeks ago both of them were doing lots of swimming, particularly in the evenings, and almost always together. Looked like they were dancing together.

Now for the past week or so, one of the julis has been spending almost all the time in one corner of the tank, at the bottom, doing next to nothing. It isn't on its side or anything like that. It tends to dart away when I come near and if it sees a sudden movement.

It is still feeding and was quite active last night, so that's a relief. But I'm still wondering if it's maybe ill, pregnant, over-fed, or even under-fed? Or maybe that's just what they do? Which would be a shame because it's such a gorgeous fish when it's being active. Even though they were active feeding last night, both of them also spent a fair bit of time in the usual corner, doing almost nothing at all.

Trying to think if there's anything I've done...

The water parameters seem to be fine - no ammonia, no nitrite, traces of nitrate, ph mid-range - so nothing has changed over the last couple of weeks. I have introduced 4 more cardinals and a snail, but don't reckon that should have had an effect.

Should I have more of them? I've read the ideal number is around 5 but I was hesitant to introduce too many at the one time.

Thanks for any advice!

Ben

 

[orangefish]

I think this is pretty common as my cories and my friends are like this- a bit lathargic during the day.
This is because cories are nocturnal, so if you shine a torch into the tank at night you will probably see them swimming about.

 

[emmettbaby]

If you watch them at night and still don't think they are very active, then you could try getting more. You don't have to go from 2 to like 6 in one swoop. Just get a couple. Maybe get one or two of each species and put those in, wait a few weeks or so and then add another one or two until you reach the needed shoal numbers for each species. Even with the extra cories, however, the cories still might not be as active just because they know they don't need to venture too far because the food is right where they are. Then again, you could just have a lazy cory.

One thing I tried when my trilineatus cories just started lying around the tank was put a bubble bar in. The extra aeration seemed to liven them up again. But they still remain on the bottom for most of the day, but when they get the urge to move around, they fly. Poor things freak out and swim into the sides of the tank when I turn the light on.