Will Livebearers Always Overrun a Tank?

[theotheragentm]

I have a 55-gallon tank. In this tank I have one male Platy and three female Platies. I know that means fry. I also have one female Molly. She has given birth twice already. Although I don't know how many times she has given birth without a male, I'm guessing it will happen again, even without a male. I do have give of her fry in a 10-gallon right now. I haven't sexed them yet, but when they are large enough, they will be moved to the 55-gallon. I am not trying to separate fry out anymore, and it will be survival of the fittest. Other inhabitants of the tank include, four Gouramis, two Panda Cories, and the floor is littered with Ghost Shrimp. I don't think the Ghost Shrimp will be eating the fry, but they take up some of the hiding places they fry would normally use. Will I be overrun with fry no matter what, or is there a chance that this fry population can be kept in check?

 

[Zagz]

In my tank there are no aggressive fish so the fry did overrun the tank. I'm not sure if the shrimp will eat fry but the molly will. You can hope for the best. If there ends up being a lot of pregnant females at the same time, you will most likely be overrun.

 

[theotheragentm]

I'm pretty sure they will all birth at the same time as the male was introduced last, so he probably made his rounds all at the same time. Do the fry have to be eaten pretty quickly after birth or else their chances of surival increase significantly? The removal of the male may have to be what I do sooner than I originally planned. The Platy won't eat the fry as well?

 

[Zagz]

My platies haven't bothered with their fry, that is not to say they won't eat them. It will depend on how many hiding spots. Removing the male may be your only option. Something I learned through experience, I had guppies in the same boat, I removed all the males 6 months ago and one female gave birth to over 30 fry again a few days ago. They can store for a long time!

 

[coldmachineUK]

Hmm...it can depend on the species, and even within that there are unexpected changes in behaviour. I'm best citing an example to show what I mean: after eight months, a friends tank was beginning to get overrun with platy fry. Before that, the fry would often get eaten by other fish. After eight months it seems like they'd 'tired' of eating them and left them be.

Your LFS should take them off your hands, either for free or in return for some store credit (if you're lucky).

 

[SeanMurphy]

You could always introduce a dwarf gourami or something of the sort that would help you take care of fry. I've had a male/female mix of mollies and guppies in my tank for almost a year, and my population has gone up and down as the months pass, but right now, 8 months later, i have the same number of fish in the tank as I did when I first introduced the fish after cycling. I recently introduced a dwarf gourami because I liked his look. I suspect I won't see too many more fry.

Edit: Now that I actually read your whole post, I see you already have gouramis. I suspect they'll keep the fry in check.