Please help! Sterbai Cory unexplained deaths...!

[azaahp2]

So, my apologies if you've already read this in the general FW thread, but I thought I'd try here in case anyone had suggestions....

Okay - so only three deaths. But still, 3. And I'm really sad about my cory... so I want to make sure there's not something I can do to prevent any more...

Yesterday I discovered a dead young male guppy - about an inch or so. Tested water and parameters fine - ph 7.6 (normal for here), ammonia 0, nitrite 0, nitrates 10 (or 20 at most).

It's a 160L tank and had a 20%-30% water change and the cannister filter cleaned a week ago.

Tank contents: 8x male guppies, 4x sterbai cory catfish (was 6), 2x adult kribs male & female and they're not friends...! Plus tiny unidentified snails and some FW limpets.

Tank is planted with a sand substrate and numerous caves,

After the guppy died I thought oh well... that's guppies. But I hope he wasn't attacked by a krib...

Now the cories - they're pretty hardy apparently, and not so easy to come by! So I really want to know - was that chance, or is there something wrong? Could he have happened a fatal nip from one of the kribs (I put in algae wafers last night), or could it be disease? Too much food? Not enough food? Something else?

Is his tummy sunken in? Is that 'ribcage look' normal? (I have no idea of 'his' gender either, bwt LOL)

And the second one - I suspect he'd been dead a couple of days... why a big empty hole in his tummy? He's just started deteriorating, or...???

And the photos don't show barbels - which seem long and healthy on my 'alive' ones. They're not acting any more strange than they normally do... LOL

Appreciate any suggestions!

 

[azaahp2]

Sorry, 3 cory deaths. Another one found today.

 

[Sprinkle]

They have no barbels. Why?

 

[azaahp2]

Sprinkle thanks for your response. For some reason I just thought the barbels were soggy and stuck to their bodies... but I think you're right, they must be gone. From my research damage to barbels is usually caused by a bacterial infection from dirty substrate. I haven't heard that they can't feed without barbels, but have heard that they don't re-grow.

Could the water parameters be okay with something nasty going on in the substrate? Or should that affect the water quality as well?

I purchased the tank including sand substrate 2nd hand and it seems to have cycled well, although there is a slow-growing brown algae that I can see in the layers under the sand (against the glass), I remove a small amount of it from the glass every fews weeks - but as I said it's pretty slow growing. Could this be anything to do with it? I do a water change and vac the sand every couple of weeks.

The two cories I have left must be a couple of my biggeset and seem active, happy, healthy and eating. Although one doesn't seem to have barbels and I'm not sure if his mouth should always look like it's stuck in an 'O' shape....? The other seems normal and has barbels on one side, but looks like it might have lost the other side.

I've removed all of the guppies so the cories have plenty of time to eat their fill. I have no idea if that's made the difference or not. It's not ideal now though because it does mean I have too many male guppies in with my females...

Now there's only two of them they seem to have befriended my rejected krib... LOL!

Some more sterbai cory juveniles have come available in my area today and I'd love to get some, but I still feel the need to get to the bottom of my other cory deaths because I sure don't want it happening again!

 

[FJB]

In order to ascertain the problem, it would be useful to know the type of sand you have as substratum (grain size, material), perhaps having a picture?. Usually barbel loss is more a mechanical issue than a bacterial issue, but of course both problems may occur in a given setup. Without barbels and with mouth abrasion or damaged mouth parts, they wouldn't be able to feed properly. This suggests that the main problem could be mechanical.
If the substratum was really that badly 'dirty', health issues would have resulted regardless of barbel loss.
Just my opinion, trying to figure what happened. Good luck!

 

[Wyomingite]

Sprinkle thanks for your response. For some reason I just thought the barbels were soggy and stuck to their bodies... but I think you're right, they must be gone. From my research damage to barbels is usually caused by a bacterial infection from dirty substrate. I haven't heard that they can't feed without barbels, but have heard that they don't re-grow.

Could the water parameters be okay with something nasty going on in the substrate? Or should that affect the water quality as well?

I purchased the tank including sand substrate 2nd hand and it seems to have cycled well, although there is a slow-growing brown algae that I can see in the layers under the sand (against the glass), I remove a small amount of it from the glass every fews weeks - but as I said it's pretty slow growing. Could this be anything to do with it? I do a water change and vac the sand every couple of weeks.

The two cories I have left must be a couple of my biggeset and seem active, happy, healthy and eating. Although one doesn't seem to have barbels and I'm not sure if his mouth should always look like it's stuck in an 'O' shape....? The other seems normal and has barbels on one side, but looks like it might have lost the other side.

I've removed all of the guppies so the cories have plenty of time to eat their fill. I have no idea if that's made the difference or not. It's not ideal now though because it does mean I have too many male guppies in with my females...

Now there's only two of them they seem to have befriended my rejected krib... LOL!

Some more sterbai cory juveniles have come available in my area today and I'd love to get some, but I still feel the need to get to the bottom of my other cory deaths because I sure don't want it happening again!

FJB has some good points. I also posted a reply in your other thread.

WYite

 

[azaahp2]

F FJB and others thanks for your replies, and happy new year to all!

I purchased the tank complete with substrate and don't know any specifics of what it is. Here is a pic I managed to get of one of my cory's eating an algae wafer - you can just see his barbel, I think he's missing the one on the other side. Hopefully this can also give you an idea of the substrate?

As well as the sand I have added river rocks, some as caves for my kribs and a few others scattered here and there.

Please let me know if any other photos would be helpful! Many thanks

 

[Lalo J.]

I'm sure that the redness on the fins should be treated with antibiotics, however if the water values that you mentioned at the beginning of the thread are true you should not have problems with the quality of the water, perhaps they are problems that these corydoras had been dragging from before that they reached your tank. Don't overfeed with the tablets and try to keep the substrate clean (I did not see anything wrong with the substrate you handle either), what temperature are you handling for them? Also it seems to me that the ideal pH for C.sterbai should be lower, maybe 7 or 7.2, that would make them feel more comfortable.

 

[FJB]

I also don't see anything wrong with the sand you are using. And I agree with Lalo J. that the cories may have come to you already somewhat compromised.

 

[azaahp2]

Thanks everyone for your help and comments. The 'redness' of the fins (unless you see something I don't?) is normal colouring for the sterbai's. After a few weeks my two surviving cories were still alive and a great deal came up for some babies from a local breeder... so I got two. So far so good... ?