Why Did My Guppy Fish Die? Pregnant?

[lucy]

I have a 50L tank with 3 guppies and 3 corydoras cat fish. I am unsure what sex my guppies are. The water quality is fine, I do regular water changes and my other fish look healthy and are swimming around as usual.

I woke up this morning to find the smaller of my guppies dead. I had noticed that the other two had been chasing her/him all the time. The dead guppy did have a darker gravid spot, and the stomach was slightly bigger than the others. Is it possible the others could have exhausted her?

She had been hanging around the bottom of the filter and heater (not the bottom of the tank) a couple of days before. I assumed she/he was getting away from the other two.

When I took her/him out of the tank this morning I noticed he/she was slightly arched.

If anyone could help it would be really appreciated

RIP wave x x

[Mike]

Well that sucks. First if your test kit is old maybe get a new one and if your changing the water with tap water are you adding de-chlorinator because the most likely thing I can think of would be there is something poisonous in the water, which could explain why the fish of smaller mass died and the others didn't or the others are harassing the smaller fish to death, in that case you can try adding more hiding areas like plants or something. Furthermore, males can harass a female to death when they are trying to mate especially if there are too many males and not enough females, what you do then is remove some males or add some females. Also to sex guppies: males are smaller, prettier, and have bigger tails, where females have small tails compared to there bodies , they are bigger, and they are more plain looking. Males and females might look alike when they are still young but when they mature you will be able to see the difference.