How Do You Determine The Sex Of Mollies?


I have 2 black molly's, and I don't know whether they are male or female. can anyone help me to determine what they are? I also have a female fancy guppy and I have no idea how to tell whether or not she is pregnant. can anyone help me?


From what I read the Male Molly has a L shaped rod fin on his anal area (under belly), the female does not. I do not have a picture to show you but there may be someone who has Mollies on this forum who might.



How to identify if you fish is male or female

Livebearers such as: Mollies, Platies, Swordtails, Guppy and Endlers are quite easy to sex when you know what to look for.

When looking to sex your fish you need to look for the gonopodium. This is the analfin on males. This fin is next to the belly of the fish.

Picture of a gonopodium:


A female’s analfin will be rounded and will look like this:



thank you so much. that really helps. I think I do have 1 male and 1 female black mollies. and I think the girl may be pregnant but how can u determine theat on a black molly?


If she is in with a male she is prego. Mollies are like rabits lol.

If you have enough room in your tank you need another female molly. MAles will stress out a singe female to much. The males can and will kill females if there is only one.


Yes, they need to be kept in trios with one male and 2 (or more) females. Otherwise the male will chase the single female relentlessly. With more than one girl he has to divide his attention.
As for being preggy, she will just get insanely fat. ;D But, like leafgirl said, if she is with a male she will get pregnant.

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