Mean male molly

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Aquarium Advice Newbie
Dec 10, 2023
Hi! I have a black male molly who is extremely....... aggressive....even with the females. Well not so much aggressive but overly "flirts" and since I went from 1 male 2 female and my female died I added another female.... well, the poor thing didn't make it more than a couple days I'm assuming from the male. So, I'm trying again and got 2 mollies to add and the boy is still aggressive in one form or another. I did get 1 male and 1 female cuz the male was beautiful and couldn't pass him up. I also have 3 fries. 2 that have been in the community tank since birth and are maybe 2 months old and 1 in a breeder box thats maybe 3 wks old. I don't have an extra tank to set up for my mean molly for a time out and we'll the breeder box has a baby in it. I rearranged some of the tank, did a water change, fed and turned off the lights prior to adding the new fish. Is there anything else I can do to curb the aggressor so he doesn't kill my new fish? He stresses me out watching him and I love the guy but goodness, he needs to learn when enough is enough! Thanks in advance.
Some fish are just jerks. If you mix male and female mollies the males will harass the females, so you want to have more females than males so the harassment is spread around. 1M/3F is usually considered a good mix. If you continue to have problems after increasing the mix, then we go back to some fish are just jerks and you should consider separating the male.

Be aware that mollies are livebearers, and livebearers breed copiously. You will get babies, if there is nothing to predate on the babies, you will get a lot of babies, and then the babies will quickly start breeding with each other, then you get a population explosion and whatever tank you have quickly gets overrun with mollies. If thats not situation you want, then separate males from females. Also, female mollies store sperm for up to a year, so once they have been with a male they can continue to produce fry for a long time even after separation.

From your other post you are keeping the fish with frogs. This isnt usually considered a good idea. If for instance your fish get sick, the medication used to treat the fish will kill the frogs. Also mollies are really brackish water fish, not freshwater.
Why does nobody inform me of this at the pet stores that they're brackish? Ugh! I knew females could hold sperm but didn't know for a year! That's insane! Since I've had my mollies (3 months or 4) I've gotten 2 seperate....... batches? Litters? Lol 1st one with 2 mollies and than a 2nd one with just 1. I read online that "mollies were a great choice to house with ADF" maybe they meant companion wise? Or lied cuz they also said mollies were peaceful! It's funny the 1st set of fries kinda rule the school of mollies and they don't mess with the babies! I put a ping pong ball in the tank to try to distract the male and give him something else to bother but he hasn't even noticed it
Because they dont know. Most people working in pet stores are just people trying to earn a living. Particularly when you are dealing with a pet store rather than an aquatics store, they arent often people from within the hobby. Their job is to sell you stuff, not to give you advice.

Mollys naturally come from a wide variety of locations, some freshwater, some brackish. But the fish farms where most of the fish come from add a lot of salt in the water to control infection. They get shipped to the store, get switched to freshwater with no acclimation, and the stress results in poor health. I wouldnt switch back, that will just cause more stress.

I wouldnt say that mollies are a worse choice than any other fish to keep with amphibians, just that its usually best not to mix them at all. They will live together until something happens.

I think a female molly can have 3 or 4 batches of fry before needing to be with a male again. 2 or 3 is the norm. In your case you have a male with females, so the females are going to continuously be impregnated anyway.
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