FishProfiles.com Message Forums

i recently added 2 platies and a swordtail to my 20gal aquarium. i already had two other platies in there and one of them always seemed to hide even though he got along with the other one in the aquarium. but now that i added two more, he's always chasing the new ones i put in the aquarium and my new swordtail! i'm guessing they're all male (even though i asked for females).

is this going to be a problem?

Check out So Very Sneaky's thread to verify gender.

If both your old platies are male and the new ones are male, too, then the aggressor might just be staking a claim on his territory. If the new ones are female, then he might just want to do some breeding. This applies to the swordtail as well, since they can interbreed.

If the new ones are male, give everyone some time to grow accustomed to each other, but if there are injuries, you might have to move some fishes around.
If the new ones are female, check to make sure they are not being overly taxed. If they are, you might need to add another female or two to distribute the chasing.