White Bump On Threadfin Rainbowfish

[-FighterFishh]

Hi there!
Two days ago I bought three threadfin rainbowfish (iriatherina werneri) for my 125L. They were the last three left at the store and unfortunately are two males and one female, so I've been keeping a close eye on the female in case she seems stressed however she's completely fine. I intend to buy more females when the store has more in stock but if I feel she's being harassed too much before then I'll put her in a breeding trap temporarily.
They were floated in their bag for a couple of hours and introduced to our water slowly. Yesterday the lights were left off to reduce stress.
Today I turned the lights on to feed them and noticed a small white spot at the base of the front dorsal fin of the dominant male.
 

 
All of the threadfins ate fine this morning and neither of the other two are showing the same spot. Behaviour wise, they've stayed at the back a lot just displaying to each other and swimming in the current which may suggest they're still a little stressed but they haven't been flicking or hiding.
I've been treating the tank with a three day course of melafix as a precaution when adding new fish.
Water parameters are all fine (I tested with an API Liquid Test Kit).
The only strange behaviour I've noticed in the corydoras they share their tank with is one flicking just now. Outwardly, there's no sign of disease or irritation and all the others are acting normal.
 
With one fish with a white spot and another flicking I would guess that they may have ich but I just want to make sure before I go treating the tank.
Could this be ich or something else?
 
Thank you!

 

[HHH]

I dont think its ich (i could be compeltely wrong and it could end up to be ich) but the spot looks a bit too big for ich and it doesnt seem scattered all over the body. I want to say it might be fungal but im not too sure.

 

[-FighterFishh]

Thank you for your reply!

I was thinking something similar but it doesn't look like cotton wool to me.

Everyone's fine this morning and all look good. The bump is still there but I've just fed them and both the cories and the threadfins are eating well.

 

[ncguppy830]

hmm strange keep us updated if anything happens.

 

[Baccus]

It looks as though it could have been a wound caused either when the shop was catching him and knocked a scale off or the two males sparring. Melafix should fix it if its a fungal growth of any sort. You could also try adding Indian Almond leaves to the tank to raise the acidity, they also have antibacterial properties.

 

[Ch4rlie]

Hmm, Indian Aldmond leaves.....sounds good to me. I too, keep just Threadfins in my tank and if those leaves are good for them then I may just order some.
 
Can you leave those leaves in the tank indefinately or just for a week or two until starts to decay?
 
Sorry for jumping into this thread, sounds too good to miss for me 

 

[-FighterFishh]

Thank you for your replies!

I'm starting to think it could be fungus. The course of melafix is finished now so if I don't see any improvement in a couple of days then I might try something a little stronger like eSHa 2000.

There's actually already an Indian almond leaf in there but it's been there for a while now so I'll swap it out for a fresh one.

Haha, no worries Ch4rlie! I leave mine in quite a while and use them in all my tanks. When they start to look a little ragged then I remove them and replace them with fresh ones. You can usually buy them in your LFS or just order a bunch off eBay

 

[-FighterFishh]

Thinking about it, could this be some sort of external parasite? It's looking more long and worm-like now, very gross!
 
Edit:
Looking at the photo I just took it does look a little like a parasite, however it seems soft and moves with the fish as he swims.
Could it actually be a parasite or just a long tendril of fungus?
 

 

[Baccus]

From that photo it does look much more like a worm of some description.
I have seen the fruiting bodies of fungus (fungi called cordyceps) emerge through insects after it has attacked and killed the insect but I am not aware of any such fungal attacks on fish.
Maybe a parasite or worming treatment would be worth a try, but first see if you can get any clearer/ closer (blown up) pictures of the complaint. I know its hard since threadfins are not the most co-operative of fish with cameras, nor are they huge. But I would hope being able to see a much bigger picture of the problem will enable us to better advise treatment.
 
I find my threadfin rainbows are still quite sleepy and in chill mode when the lights first come on in their tank in the morning, so that might be the best time to try and snap some closer pictures of the affected fish.

 

[-FighterFishh]

I looked up different types of parasitic worms in fish and the only one that looked a little similar was anchor worm. However, this worm has two little prongs and from the photo it's quite clear that my boy doesn't have that. He also doesn't have the behaviour of a fish with parasites - he's completely active, eats well, socialises and doesn't have any strange discoloured patches or bumps. Also, if he had a parasite right next to his dorsal I think it would pain him to display, and he doesn't seem to have any problems with displaying!
 
The possibly good news is that the white string seems to have gotten thinner and seemingly looks like it's starting to break away. I managed to get this photo though he was clearly just about to move off so it's a bit blurry, I'm afraid!
 

 
I'm hoping that this may suggest that it's some form of fungus. I've been treating with the Melafix and esha 2000 for the last couple of days and it seems to be working. Fingers crossed!

 

[Baccus]

Its good that he is not showing any sign of distress and that whatever it is seems to be reducing in size.
keep us posted, I hope he makes a full recovery, they are a fantastic fish and worth any hassels.

 

[-FighterFishh]

It's even smaller today, seems to be nearly gone! Whatever it is/was, the medication seems to be working on it.

I also managed to pick up six more threadfins from my LFS so once they've gone through quarantine and my dominant boy is free of whatever this is then I'll pop them in. It'll be nice to see them in a proper shoal again.

Thank you for all your help!

 

[Ch4rlie]

Thats good news then, hopefully that will be the end of that. 

 
Reckon it sucks when your fish are not themselves and ill. Luckily looks like yours was not too bad and just a temporary thing.
 
Nice one.

 
And yes, its nice having a shoal of Threadfins, thats what I have in my tank, good to watch!