Mysterious lump on my ray

[aro-spino]

Just noticed a lump developed overnight on the back of my stingray a moment ago. It looks like simple nonspecific edema. I have never observed anything like this before, and would really like to know what it is.

Additional information:
He is fed purely on mp although he takes sw as treat.
The only other fish in the aquarium are 1x HBRTG, 1x Tigrinus & 2x IT.
I've a UVC 'On' 24/7.

Water conditions are as follows:
Ammonia- 0ppm
Nitrite- 0ppm
Nitrate- 50ppm
pH- 6.5 to 6.8

What could have caused it? Any remedy? Would really appreciate all inputs. Thank You!

Here's a pic taken a moment ago.

[sixthbrand]

Darren, sad to see this.. sorry cant be of any help. Maybe more exp ray keepers can give some advice.

But imo dun think it's due to water parameters or diet.

Hope it recovers asap.

[leezhengxi]

first time seeing this as well , did it happen suddenly ? or did it gradually become bigger ?

Hope some more experienced ray keepers can shed some light

[aro-spino]

Originally Posted by sixthbrand

Darren, sad to see this.. sorry cant be of any help. Maybe more exp ray keepers can give some advice.

But imo dun think it's due to water parameters or diet.

Hope it recovers asap.

Thanks Kent.

Originally Posted by leezhengxi

first time seeing this as well , did it happen suddenly ? or did it gradually become bigger ?

Hope some more experienced ray keepers can shed some light

Woke up this morning to see this balloon, got a shock too...

[leezhengxi]

Originally Posted by aro-spino

Woke up this morning to see this balloon, got a shock too...

Maybe you would like to wait a few days and observe its condition

[farish]

How big? M or f?

[aro-spino]

I know what you're thinking, Bro. But it is a He.

[farish]

I guess have to take a wait n see approach.

[dolphex_tang]

Bro, is he eating still?? And his under belly got any red spots??

[aro-spino]

Originally Posted by farish

I guess have to take a wait n see approach.

Thanks Bro.

Originally Posted by dolphex_tang

Bro, is he eating still?? And his under belly got any red spots??

Have not observe any abnormality under the disc. I've performed wc with dissolved salt & Upz temperature to 31 deg C yesterday thus no feeding since. Will update it's progress later. Thanks Bro.