Molly is very big - normal??

[Kelly Preussner]

I purchased this small female Molly from the fish store about 2 months ago (maybe 1”) and it is now HUGE! I don’t mean pregnant huge since I have no males & it’s been 2 months now & still no fry. It’s just a very large fish. Not just in length (she is now about 2”) but just a big fish. Is this normal? She looks great & healthy but also like a shark in my tank lol.
I have enclosed some pics.

 

[Naughts]

She still has some growing to do, adult mollies are usually 3-5" and females are larger than males. They need a 3' tank.
@emeraldking, is she gravid?

 

[JackGulley]

Yeah adult mollies grow to 5-7 inches and need a 30 gallon or so. If you want something similar but smaller, Platys stay around 2-3 inches and are suitable for a 20 gallon or *maybe* a little smaller? (I’m not an expert here) Guppies and endlers are in the same family and stay about 1 inch, and will do great in any tank over 10 gallons. You might also see swordtails, which are closely related to platys but grow anywhere from 4 to 8 inches depending on genetics, and also probably need a 30 gallon. How big is your tank?

 

[TC33]

I had a dalmation Molly once that was sold as female (It did look it) I bought it with 3 other similar Mollies (2 more female and a male)

3 months later is was completely black, male and about twice the size of the other Mollies. (Even though people say females are bigger)

Spent its days beating on all the other fish in the tank.

Maybe keep an eye on it

 

[Kelly Preussner]

Thanks all for the replies! I didn’t realize mollies got that big!! I thought they were in the same category as platys. I have a 20 gal tank and she is my only Molly. All my other fish are guppies, she is fairly peaceful but unfortunately I can’t just get rid of her. I was transitioning to a guppy tank and my daughter wanted 1 black Molly.

 

[Naughts]

Well at least black molly are smaller than sailfins. And you just got one!

But that round belly is somewhat suspicious

 

[emeraldking]

I purchased this small female Molly from the fish store about 2 months ago (maybe 1”) and it is now HUGE! I don’t mean pregnant huge since I have no males & it’s been 2 months now & still no fry. It’s just a very large fish. Not just in length (she is now about 2”) but just a big fish. Is this normal? She looks great & healthy but also like a shark in my tank lol.
I have enclosed some pics.

There are officially two different sized black mollies. One that stays smaller and one that grows up the size of a sailfin (not the Poecilia veilfera but the size of a Poecilia latipinna). But the males of the bigger sized black mollies will be short finned and they're actually a result of the Poecilia sphenops x Poecilia latipinna. But the males didn't inherit the gene of a higher dorsal.

She still has some growing to do, adult mollies are usually 3-5" and females are larger than males. They need a 3' tank.
@emeraldking, is she gravid?

She could be gravid but she could also just be well fed.

 

[FishyD]

I purchased this small female Molly from the fish store about 2 months ago (maybe 1”) and it is now HUGE! I don’t mean pregnant huge since I have no males & it’s been 2 months now & still no fry. It’s just a very large fish. Not just in length (she is now about 2”) but just a big fish. Is this normal? She looks great & healthy but also like a shark in my tank lol.
I have enclosed some pics.

Sounds like you are taking good care of her. You will occasionally see mollies that stay fairly small (possibly due to poor breeding or diet), but they get large under normal conditions. The mollies you typically see at the store are quite young. They would look like juveniles if you saw them a month earlier.

 

[Kelly Preussner]

There are officially two different sized black mollies. One that stays smaller and one that grows up the size of a sailfin (not the Poecilia veilfera but the size of a Poecilia latipinna). But the males of the bigger sized black mollies will be short finned and they're actually a result of the Poecilia sphenops x Poecilia latipinna. But the males didn't inherit the gene of a higher dorsal.

She could be gravid but she could also just be well fed.

How can I tell what I have? I was hoping for a smaller Molly. That is what I have had in the past

 

[emeraldking]

How can I tell what I have? I was hoping for a smaller Molly. That is what I have had in the past

You've one of them. If she'll go for the 3 inches or more, she's of the last type I've mentioned.

 

[EllenAliciaJordanScusa]

I had a black Molly that looked exactly like yours. She never grew as big as everyone is saying. She was only like an inch and a half maybe as an adult. And I had her in a 10-gallon tank just fine for a long time. However, this reminds me of when I first got her from the Pet store. She was skinny like you are saying. It was about 6 months later she started putting on weight. I thought she was just overeating or something. Her belly got pretty big, but I thought she couldn't be pregnant because it has been too long without a male. Well, she ended up having a ton of babies. I don't remember how long she was fat (I felt like she was pregnant forever) she exploded with baby Mollies though and turned around 2 weeks later and had another batch of babies! I learned that day that Mollies can hold sperm and be pregnant with no males around.

 

[Sparx]

She does look pregnant. As Ellen said above..

Mollys can hold sperm and re-pregnate themselves even with no males around. Their gestation period is around six to ten weeks so she may still give birth yet.

I’ve got mollies and they have produced three batches of fry, I currently have two females that look exactly how yours does and I’m expecting them to have babies very soon.

If you decide you want to raise the fry you will need to separate her because In a community tank the fry quickly get eaten, then once theyre born separate the mother from the fry because she will also eat them..

I really hope she’s pregnant for her sake and not sick

 

[Sparx]

 

[Sparx]

Oh and on a side note.. Mollies and Guppies have been known to cross breed ….

 

[emeraldking]

I learned that day that Mollies can hold sperm and be pregnant with no males around.

Female mollies can store sperm packets for over a year without loss of quality of the sperm.

Oh and on a side note.. Mollies and Guppies have been known to cross breed ….

Yes, but only when you keep one sex of one of them and the opposite sex of the other. If you keep both species while there are both genders present of both species, the chance that they'll crossbreed is as low to zero.