Platy question

[Johnny B. Goode]

I have a 10 gallon with 5 platy. 1 male and 4 females. I am 1000% sure without a doubt only one is a male. The issue is he is super aggressive to all the females except the one he keeps trying to breed with. She has been receptive to him and I'm pretty sure she is pregnant. Her belly has nearly doubled in size in a week. Why would he be aggressive to the other females? They are all mature enough to breed. The tank is very heavily planted and has driftwood. Plenty of hiding places and line of sight breaks. He's not overly aggressive to any particular female. He just not "nice" to any of them except the one. Any ideas what is going on with this guy?

[Dawn T]

Simple answer - he's a butthead. LOL Seriously though, fish are like people. Regardless of species, they have varying degrees of aggression and passivity. Even among peaceful species of fish, you can find individuals who are more aggressive than the others. Though you have to watch closely to figure it out with some, there's always a pecking order - sometimes that stays in the same species; other times it flows to other species in the tank.

I've had aggressive male platies before. In fact, it's not as unusual as you'd think. Swordtails, same thing, though they can also manifest aggression toward other species occasionally. Sometimes the male platies have are only been aggressive toward other males, but sometimes their aggression has been more generalized. They seem to pick their favorite females, too. It's weird, as you wouldn't expect it, but that's been my observation over the years with the species.

[Kirsten]

Maybe he's pestering them to mate with him? Unless they're having trouble feeding or getting injured from his aggression, I'd let them continue their fishy politics. Once there are babies in the tank, there might be a few more males to horse around with and a few more females to spread out the harassment.

If he's getting too aggressive, might want to try putting him in a breeding box for a timeout.

Me, I had to change up my feeding habits because the biggest female platy (who may actually be a swordtail) freakin loves sinking wafers and thinks they all belong to her and will get nasty with anyone else coming near "her" wafers. Of course, the other females keep trying and keep getting nipped and chased off. So no wafers for anyone for awhile.

[Colu]

Are you sure the other are all female male platy have a gonopodium which is all long anal fin with a pointed end