Red Platy question

[jojojc]

I am new to aquariums and this wonderful hobby, about six weeks in. I have two red platy's . In a 30 gallon tank with five seprae tretra's , three gold wags and six danios .
I notice over the last two days one of the platy's has been hiding on and off at the bottom of the tank inside or behind the plants. Staying very still.. When it's not hiding it is out with the other fish and seems perfectly fine. I also have noticed it looks a little bit fatter so I am not sure if she is pregnant. Honestly I don't know if it is a male or female.
I have attached a pic

Any suggestions on what is going on?

 

[sabrinarichard]

Looks like a male from that picture but the underbelly fin could just be clamped and she's swimming so it's just an impression. I don't see a gravid spot either so not pregnant. Is your tank cycled ? If yes, and your parameters are ok, I once had a weird platy once that use to just the exact thing yours does, he died during a tank transfer ..

 

[jojojc]

Water test showed high ammonia yesterday, did a 5 g water change yesterday afternoon.

 

[sabrinarichard]

Ok.. So I'm really not a pro at this but 50% water changer ASAP and check the water to make sure the parameters aren't too high, they fish can be very sensible to nitrites and ammonia.. You need to get your tank cycled or your fish night die :-( there's a ton of info on it in here but as I said I'm not an expert my any means..