What is this on this guppy?

[Sandra the fish rookie]

My 20 is the only place I have guppies. There are a lot of juveniles, different ages, ect. Some of the older ones have started to die off. There have been no signs of disease that I can see upon examination. It appears that the females pass away after the second or third birth of fry. The young males are becoming a bit feisty with the older ones. 

They are all mutt guppies, regardless thriving and doing well. I had 2 females with what appeared to be genetic deformities (no signs or symptoms of TB which I watches for). One of the 2 died, the second one is in the 10 QT (where she is living her best life all alone not being chased). 

This morning I round this guy not looking great. He was 1 of 2 that were similar in color and size. The smaller of the 2 died and here he is with this ??? not sure what this is??? ALL these guppies whet through quarantine, with all the meds and a full cycle of paracleanse prior to being introduced into the 20 G. 

He has always been on the small side.. but he doesn't look great to me .. but is eating..??? 

Parameters:

Temp =77.9

Nitrite = 0 ppm

Ammonia = 0ppm

PH = 7.3

Nitrates = 20

KH = 5

GH = 17

See pictures below (FYI he is in the QT tank as well)

[Colu]

It difficult to tell off your picture does he have a white patch on his back

[Sandra the fish rookie]

@Colu he has a pale yellow strip along his back. 

I tried to get a picture from the top.. but can't seem to get it ... I modified one of the ones attached .. not sure if it will help at all. 

 

 

[Colu]

Does it have fuzz or cotton wool like apprance on his back also that could be a prolapse epsom salt bath will help your fish reabsorb the prolapse as it acts as a muscle relaxants I would treat with epsom salt 1 table spoon for 2 gallons for no more than 15 minutes 2-3 times a day I wouldn't feed for a couple of  a days during treatment

Edited July 26, 2021 by Colu

[laritheloud]

I have no idea what that is. It looks like maybe a prolapse but it's huge???

[Sandra the fish rookie]

@Colu What else could I use instead of the QT tank to do his soaks? a container of some kind? 

[laritheloud]

On 7/26/2021 at 10:24 AM, Sandra the fish rookie said:

@Colu What else could I use instead of the QT tank to do his soaks? a container of some kind? 

I used a bucket for an epsom salt bath, then moved my fish to a QT tank for recovery. You could put him back in the main tank if you don't have a QT.

[Taco Playz]

I use fritz Aquarium salt. It's probably the best choice for salt but Epson salt should work too. My LFS has it for 3 dollars for the big thing of it so you might be able to find it for cheap. If not then definetly get it off the Co-Op https://www.aquariumcoop.com/products/fritz-freshwater-salt-1lb?_pos=6&_sid=b720825c1&_ss=r

[quikv6]

If that is a prolapse (which it looks like it is), Colu's advice is solid. Epsom salt baths (3-4x a day for 15 mins at a time) would be your best best.

I had 2 fish which had similar prolapses. I used a small deli container for the bath, and mixed in Epsom salt (guestimated the amount...probably 1/4-1/2 teaspoon). I let the fish soak in it for 15 mins, and then returned the fish to the tank. Do not add the Epsom salt water back to the tank.

In both cases, it took a few days for it to be reabsorbed. I did the bath during normal feeding time, which was the best method for me to fast the fish.