Pale, Bloated, Protruding Eyes On Tail-less Pygmy Cory

If both eyes are protruding it does sound like an internal infection of some kind. Just one eye would be physical damage. The problem is that the underlying infection could be bacterial, viral or even protozoan. (The recent outbreak of cryptosporidium in Preston shows there can be protozoa in the water supply, though I have no idea if this one can affect fish)

We don't have much in this country to combat bacteria. There is nothing to combat viruses. I have read that metronidazole combats protozoa but that is prescription only.

I would try the eSHa 2000, it can't do more harm. I do wonder if there was something wrong with these cories when you got them. You aren't having much luck with them 

Third and final day of eSHa 2000 treatment.  Tail-less Cory is looking no different.  He doesn't look at all distressed, his dorsal fin is upright, but he has just been sitting, relaxed, on the bottom of the tank throughout this time.  I'm unsure what to do next but would imagine that I'm best to leave him in the QT with the eSHa 2000 in it for at least a few days.

Separately, another pygmy cory seems to have red anal fins.  I noticed this possibly last week but just assumed it was 'waste' coming out and that he'd been eating the red-coloured Hikari pellets.  I noticed it again the other day and assumed the same thing, and that he was possibly constipated.  However, this morning, I got a chance to take a closer look and it seems to be his anal fins.  A quick google search suggests that this usually points to water quality issues, low PH, etc, but these are consistently good, albeit PH is consistenly 6.4 which is on the low side.  Since Mon and realising Tail-less Cory was ill, I'd actually been dosing the main tank with Melafix which I bought the same day as the eSHa 2000 - the shop assistant said it was useful as a mild form of medication and many shops use it in their tanks with new fish as a precautionary measure to keep disease at bay (and he also mentioned that harlequins these days succumb very quickly to disease which of course I didn't want to risk happening).  I was just planning to use it for 3 days which is more the precautionary measure whereas extended treatment for 7 days is for actual disease.  I'm now unsure whether to move Red Anal Finned Cory into the QT with the eSHa 2000 - would this be safe after several days' Melafix treatment and going in to a tank with 3 days' worth of eSHa 2000 in it?  Would leaving him where he is likely affect the other fish?

I notice Thinkfish quotes pygmy cories' ideal PH range as 6.5+ while Seriously Fish quotes 6.4+.  I'm beginning to wonder if a PH of 6.4 is just too low after all or whether I've just been unlucky with these guys.

Thanks, Sue.

I realised that Tail-less Cory had been sitting serenely in the same spot for 24hrs, if not 48hrs, and I'd never seen him go up for air. He did flicker slightly when I touched him with the net, though, but was still sitting serenely in the same spot this morning, dead this time although feigning life (in contrast to 2 other cories which had been excellent at feigning death). 

I didn't move Red Anal Finned Cory into the QT yesterday, as I realised death for Tail-less Cory was imminent and he probably was best left in peace. I will clean out the QT and move this other cory in to the QT.

I just wonder if the remaining 3 cories might do better on their own in a separate tank, perhaps with some new same-species tankmates. I made the mistake of voicing this thought this morning but it didn't go down too well...

Thanks, Diz.

The cories were actually perfectly fine for 5 months, then things started to go awry at the end of May/early June. I don't think I'll ever truly get to the bottom of what's been going on. I'm not going to get any more for that tank, though, as I was already "pushing" my stocking limit.

I think, though, if I were to get more/give advice to others, I would keep them in larger numbers and possibly in a same-species-only tank or with tankmates the same size such as micro rasboras or CPDs. I think panda cories might be better suited size-wise to x-ray tetras and harlequin rasboras. Currently, there are 3 small pygmy cories which don't exactly look as though they're thriving in with 6 x-ray tetras swimming immediately above their heads, sometimes knocking them as they swim over them, and 6 harlequin rasboras immediately above them - the tank is quite "bottom heavy" and, currently, might feel a bit overwhelming for the 3 remaining pygmy cories.

I've just been to the other of the two LFSs ie the one which I didn't buy the pygmy cories in, to have a look at whether they had any in stock, purely for research purposes. (Other Half came with me as wanted to keep me "in check" as he detected signs of MTS.)

What I noticed was that the little pygmy cories' barbels were quite prominent in comparison with my own ones' barbels. Perhaps it's just because they are a smaller size overall and therefore the barbels look more prominent, but it did get me wondering whether my own pygmy cories' barbels have become finer/shorter for any particular reason, and indeed whether this may be contributing to the early demise of half of the shoal. I have Unipac Tana Sand as the substrate, a rock cave (only really used by one x-ray tetra after for an hour or so after the weekly water change - she's much less nervous now than she used to be) and a hard ornament/bridge, the latter of which the pygmies do like resting under and foraging over the top of now and again - see pic. All the plants are silk plants. I'm probably "clutching at straws" here but I'm wondering if there is anything about the set-up of the tank that perhaps could be improved for the pygmy cories or indeed generally for them, the x-ray tetras or the harlequin rasboras? [NB. the lights can't go on because the x-ray tetras absolutely freaked out any time I tried that before - and so real plants are not an option.]

The only other "coinciding factor" is that, a week prior to the first fatality, we installed sonar mice deterrents in our flat - allegedly, humans and other pets should not hear these; however, I do have very good hearing and did hear these myself (albeit I have got used to the sound) but wonder if the pygmy cories happen to have sensitive hearing and have been unduly stressed by them, perhaps in addition to the decrease in numbers of their own species and the increase in numbers of the other fish through the introduction of the harlequin rasboras.

The Tana sand feels smooth but, when rubbing it between finger and thumb until just left with a few pieces, the white pieces are slightly more 'jaggedy'.  Apparently the size of the sand ranges from 800-2000 - see http://www.unipacpet.co.uk/aquatic/aquarium-sand/ so I'm assuming the white pieces are the ones that are 2mm.  I had always wondered about black sand and notice that its size ranges from 1000-1200 - might that be better?  I don't want to make major changes and stress out the fish unnecessarily, but, equally, if changing the substrate (and/or removing the rock cave and/or hard tunnel bridge ornament) might help, then I'd be happy to try that.

Just checking that I've understood this correctly:
* particle size has to be small AND additionally feel smooth?
* If 0.5mm (500 microns) was too big for pygmy cories, then, of the Unipac's list, actually only silver sand (300-400 microns or 0.3-0.4mm) or aquarium silver sand (150-250 microns or 0.15-0.25) would be small enough for pygmy cories; additionally, it would have to feel smooth as well as be small-sized?

I've checked through video footage I've taken of the fish. Of the few that the cories appear in, there is one that darts past off the substrate - and his barbels are noticeable, and, in fact, the cories seem much livelier then than they do now, flitting from plant to plant, busily foraging on them and rarely stopping to rest. It's as though something has gone awry in recent months, yet, oddly, I'm really diligent with water changes (weekly at the longest gap, sometimes twice weekly or ~ every 5 days) and taking water readings (originally twice daily, now several times per week) - and they're consistently good.

It does sound as though your and has been abrading the barbels. You would have noticed if it was an infection.

I think I'd been seeing two strands of red waste coming out of the fish's vent.

This is ringing alarm bells. Are you sure they were strands of poo not camallanus worms? I know, I'm obsessed with this infection after having had it myself. Well, not me but my fish.

What you need to do is try and watch them while they are motionless and see if anything is protruding. This is not terribly easy with a fish that sits on things when they rest. They need to be motionless as camallanus worms go back inside when the fish is swimming. And check all the other fish too.

If you see any trace of it in even one fish, you'll need to treat the whole tank, I'm afraid.