Tetra With What Looks Like A White Worm Protuding From Body

Hi all,

I'm new to this forum - been reading a lot of posts but this is my first! Also new to fishkeeping. I made the mistake of believing everything the lfs told me, to be fair to them they've been great in some respects, but they didn't tell me about fishless cycling, quarantining, ideal hardness for fish, blimming snails on plants, etc. Live and learn!

I'm posting because I can't work out what's wrong with one of my cardinal tetras. Everyone in the tank is behaving normally and happily. The fish in question also seems high up the pecking order and is also behaving fine. It just has something white sticking out of it's side. It doesn't look like pictures of anchor worms, is it some other worm, or some sort of fungus?

Some videos (they seem to come out better than photos)
Yesterday
https://goo.gl/photos/Exb3RvP1tLSAaXiq8
Today
https://goo.gl/photos/egi7N5edGGNAbkrQ7

I should note that until a few days ago we had 3 zebra loaches, in case it's relevant. We've had them about 3 or 4 weeks, and they all behaved the same, sometimes chasing each other, sometimes chasing the tetras, gobbling up food, and seeming generally happy, but then being new to fish I don't know for sure. One of them started out smaller, but never got a belly in the way the other 2 have, but we'd only noticed about a week ago and then it just disappeared over night. He did seem to be chased more often than not so maybe bullying and not eating? It's not on the floor, I seriously doubt it's found a hiding place and not ventured out at all. I immediately did a water change and took out all the decor and wood so I could thoroughly vacuum, and didn't find him. Also checked the filter and the filter tubes. The plants are all pretty new and there's no carpet type plants so not really any places left to hide. So I'm assuming he died and got eaten. We did think he was thin compared to the others, but I don't think he wasted, he certainly didn't look like pictures of skinny disease I've seen. That's also when I first saw this tetra.

I checked parameters too in case of ammonia spike:
ammonia: 0
nitrite: 0
nitrate: 40 or 80 (I can't tell the difference between the colours on the chart)
tap water nitrate: 10 or 20 (ditto, but legal max is 50 and it has been worse)
ph: 8.2

Food: otos eat the brown algae and aren't interested in anything else like algae wafers, mostly granules for the other fish, sometimes soaked in garlic juice (have been doing that since first seeing the white 'thing'), as a treat frozen bloodworm.

I know now that the pH and water hardness is not ideal for the cardinal tetras and probably the otos too - the lfs uses the same tap water so didn't think it was an issue, although I have to say the cardinals are generally doing well, even the smallest one who kept ending up in the filter canister (plugged that up with a course sponge). I also know that I need to do something about the nitrates. I will do more water changes, vacuuming, and have now got a filter in the kitchen working which removes nitrates and the hardness (we already had it installed so this is a simple solution if it works). With each water change I'm using 25% of this filtered water - anymore and I'm worried about bringing the pH down too quickly, but also wouldn't use more than 50% anyway because as I understand it you want some of the minerals and hardness. I could do with some hardness tests - I have the API liquid tests but only pH, ammonia, nitrite and nitrate. Anyway I can ask about that later.

That was a long post, thank you for reading it if you got this far, and hopefully someone can tell me what I need to do for the fish. I don't currently have a quarantine tank but can sort one out over the weekend if necessary.

I can't tell enough from the video to give a definite diagnosis I'm afraid, but more than happily to help you try and reach one.

Have a read of this http://www.tetra-fish.com/aquarium-information/aquarium-fish-diseases-how-to-spot-them.aspx

See what conclusions you come to.  If you could describe the fishes behaviour as well that would be helpful.

I'm tempted to say physical removal but as the fish seems to be doing ok right now there is no way I would risk this very stressful action for you and the fish right away.

Thank you both. The fish is behaving completely normally, no other symptoms. That parasite Sue mentioned looked most like it, but there was no sac over it and it was looking a bit thick and misshapen for a worm.

Development this morning, when I first checked the tank its lights were still off but the sick fish was swimming about and if anything the white thing was smaller but still there. A couple of hours later, we counted the fish, one missing, but I don't think it's the same tetra, the one I think it is is guarding the same territory waiting for food as usual but now has what looks like a small white mark barely visible, nothing protruding from it. Can they get infections that ooze thick white mucus (like we get pus)?

When I went to bed there was another tetra who was resting on a branch with no colour, in hind site this might be the one that disappeared but it was late with no lights in the tank and not much activity so didn't think anything of it at the time. It was one of the biggest so possibly one of our first and damaged by the fish in cycle which I now know was not a great idea, but also when we bought them there was a dead fish in the tank so perhaps not the best stock either.

So I think I'm just going to keep going with normal maintenance and keep an eye on them all, unless anyone thinks that's not the right course?

Thanks Sue, yes I thought he was just sleeping at the time so maybe not relevant after all if that's normal (and it was dim in the room as well). I'll do more water changes than usual over the next few days, and fingers crossed that's the end of it.