One of my zebra danios has an large lump under its mouth. It looks like it’s got something dark inside it on one side which is a bit odd. It’s swimming normally, eating ok and doesn’t seem in distress. I’m just worried it suddenly will become noticeably ill as it’s so big. It’s been there about a week or so.
Any ideas what it could be please? I’ve searched images on lots of Internet forums but can’t see anything that looks quite the same.
My cold water tank has been set up 2 years and is 150l with a fluval 206 pump. It contains 5 danios, 8 platys, 1 weather loach, 2 goldfish.
PH 7.5 Ammonia 0 Nitrite 0
I recently treated the tank with melafix as my only remaining male platy had clamped fins and a cottony fuzz on him which has now gone ( although he still is a bit lethargic)
I did try as I have managed to get a few but I can’t seem to upload them- apparently they are too large. I spent ages trying to reduce the pixel size then it still wouldn’t upload... I will try again.... thanks !
What sort of substrate do you have? Is it black sand that might possibly have been ingested (e.g. if the fish forages / was foraging to retrieve some food) or do you have large gravel pieces and which would be far too large for that to happen (i.e. and therefore eliminates that as a possibility)?
Yes my substrate is mixed colour so there are dark ones similar size although I think maybe a bit larger.
I did initially wonder about that possibility but I’ve never seen the danios go near the gravel to ingest it. They tend to swim about the tank rather than snuffling round the bottom. I have had that with a goldfish once or twice but their mouth was jammed open and so that made me think it wasn’t in this case plus it’s quite far down the mouth. I can’t rule out for definite though- has anyone had a danio who did that?