I have a problem with my guppies and I have an idea of what might be going on but I'm not sure how to fix it.
I have 2 female guppies in a 10 gallon. The tank is cycled and I've had the fish for about a month now, they are the only fish in the tank.
Recently one of them, the smaller one with an orange tail has been chasing the bigger one, which isn't as colorful. It's getting kind of serious now, since sometimes I would find the bullied fish hiding at the bottom of the tank and gasping due to stress.
I say it's stress because I'm pretty sure it isn't a problem with the water. I tested it with the API liquid test and everything came back normal. The ph is a little high, 8.2, but it's been consistently at 8.0 to 8.2 ever since I got the fish so they should be used to it.
I have one idea of why this would be happening. I noticed when I bought the fish that the "bully" fish is fatter than the other one, and has a darker gravid spot, so it might be pregnant and is acting aggressive as it's almost time for it to give birth. But they were separated by sex at the store, so that seems unlikely.
Also, I'm thinking that getting another female guppy might cause the bully fish to lose interest since there are more tank mates, but I don't know if that's the wisest thing to do, especially if it's actually pregnant.
Any thoughts or suggestions on what I should do? I would really appreciate it.
I don't think it's a water quality thing. Could be pregnancy related or it's just a social issue. I truest believe that guppies have personalities and this guppy you have might just be that kind of mean fish. Either wait for her to give birth aNd observe her behavio for changes. I doubt it'll change significantly but if it were me I'd wait for the fry and then inform & give her away to someone via CL or whatever method.