My platy has not eaten in 2 or 3 or more days

[NorthPoleFish]

My tank Info:

20 gal tank
~50% water changes every 2 weeks (try to do more, but not always successful due to schedule)
Nitrate: 20 ppm
Nitrites: 0 ppm
Ammonium: 0 ppm
pH: 7.8
A planted tank, but plants are starting to die and thin out since hornwort is taking over
Tank has been set up for over a year
I feed the fish once a day, in the morning. Either frozen blood worms (which they love), or a pinch or two of Fluval Bug Bites Tropical Formula. And the rare occasion freezed dried blood worms if I'll be gone a couple days (I usually sprinkle some in the hornwort for them to find later).

I have 4 platys in the tank, 4 female and 1 male. My blue platy is mother to the other 4, so only the big blue platy was store bought, all others born and raised in my tanks. One of my platys isn't eating or at least, I have not seen her eat anything in 2 or 3 days, maybe longer (I'm not sure). She looks fine and healthy, although a bit smaller than her siblings, but she was always smaller. She did grow right along with the rest of her siblings and never showed any signs of anything wrong. Always had a great appetite and was always swimming around. Now, she won't eat, doesn't even seem interested in food even when swimming right by it, and tends to hang out at the surface. If she isn't at the surface, she is just chilling at the bottom of the tank, not doing a whole lot. (See attached photos). It is a little hard to tell, but she might be moving her mouth a bit more than the other fish. I was gone for almost two weeks at the beginning of the month and just left the fish be. I did about a 50% water change before I left, feed them the morning I left, and did not have anyone stop by to feed them (tried that once and it did not work out well for my previous fish). When I got back, I did another 50% water change, vacuumed the gravel, and last week, I changed the filter. All fish seemed to be doing fine after the water change and even the filter change. It has just been the past 2 or 3 days I've noticed my one platy isn't eating.

Any suggestions as to why she won't eat? Any suggestions as to what I can do for her? I do have a 3 gal cylinder cycled tank that can be used for a temporary hospital if need be. It only has a couple pond snails in it right now. I have done some research on my own to try and figure out what could be wrong and what I can do to help my platy, but I really don't know. Is it possible she has a bacteria infection or an intestinal issue or parasites or something else? And, depending on what she has, can she spread it to the other 4 fish in my tank? Her 3 siblings are doing great, eating like little piranhas and swimming around normally. Her mom isn't doing too bad, but has a tumor on her side, which has gotten bigger, causing some swimming issues, but mom still eats really well.

I am very limited as to what products I can get in my town, since I only have a PetCo that sells fish products. I generally have to order most things. Any help or suggestions would be greatly appreciated.

 

[Burleson]

I don’t know much about platys but my first thought was that maybe she was pregnant (since there is a male present) and going into labor because I know most of my live bearers stop eating when they are getting ready to give birth but after looking at the pictures I’m not sure

 

[NorthPoleFish]

I don’t know much about platys but my first thought was that maybe she was pregnant (since there is a male present) and going into labor because I know most of my live bearers stop eating when they are getting ready to give birth but after looking at the pictures I’m not sure

I'm familiar with pregnant platys, and she doesn't have an extended pregnant belly. So, I'm not sure either.

 

[GaryE]

There is no going into labour for them, though dropping fry must be uncomfortable. Unless she starts to get thin, I wouldn't worry. A lot of fish don't eat at the surface when food goes in, especially if another fish is harassing them. They get food off the bottom, etc.

Platys should have a little bit of a veggie component to their diet - try adding in a greenflake.

There is a strong possibility she's ill, but treatments when you don't know the illness can be harmful. If you go for the wrong one.

The tumour on the older Mom might be a major clue.

 

[NorthPoleFish]

There is no going into labour for them, though dropping fry must be uncomfortable. Unless she starts to get thin, I wouldn't worry. A lot of fish don't eat at the surface when food goes in, especially if another fish is harassing them. They get food off the bottom, etc.

Platys should have a little bit of a veggie component to their diet - try adding in a greenflake.

There is a strong possibility she's ill, but treatments when you don't know the illness can be harmful. If you go for the wrong one.

The tumour on the older Mom might be a major clue.

Thank you for the suggestion of adding a veggie component to their diet. I will try that. I do have some algae wafers that I toss in every now and then, but I understand that is different than veggies.

The tumor on Mom started showing up about 6 or 7 months ago, I really can't remember. She just started developing a lump on her right side, behind her fin. Doesn't seem to bother her or slow her down, but I do think it is starting to affect her swimming since she'll be nose down if not swimming. I've given her a few epsom salt baths, that seem to help a little. No idea why or how she started developing a tumor, but none of her babies have any, yet. We shall see.

 

[GaryE]

It could be a cyst from a communicable bacterial infection - untreatable but common in pet store fish. I hope not, but such things are possible. It's to be watched.