PHI

I've raised livebearers for years and I've heard of and seen swordtails change sex. I've never heard this same trait in Mollys. However, I have a Molly now that not only changed sex, but gradually changed color from a marble to fully black. When I first bought the fish, it was a female marble about 1 inch long. It looked to be a normal marble molly. I also had 2 other females mollies and 1 male molly among some other liverbearers. Now, the fish is definitely male, completely black, and a sailfin about 2 1/2 inches long. I've watched the gradual color change from black and silver to all black over several weeks. I've never heard of mollies changing like this and neither has my LFS. Has anybody else heard of this?

Stradius011

Mollies and swordtails can't change sex! Only clownfishes can do that. All fishes change color gradually as they grow. Go to the livebearers board and you'll see a board called "sexing livebearers" and it'll show you how to sex livebearers.

PHI

Thanks for the reply, but I'm not asking if they can change, I'm asking if anybody else has had this occurance with mollies. I've been raising livebearers for nearly 20 years. I do know how to sex them. This molly was (or appeared to be) a fully grown female marble molly. She was slightly larger than the male I already had and stayed this way for several months. Gradually, she then started changing color to solid black, began growing larger, and during this transition, she became a male.
I do know this can occur if you have a group of female swordtails, and no males are introduced into the tank for several months. You will usually get one female that becomes male. The tail isn't quite as long as normal males, and the body is still shaped like the female, but it will be able to breed with the other females. I've had this happen more than a few times over the years.
I had never heard of this happening with mollies though. I was just wondering how rare this was.

Dino

I have heard of other cases, but I have not seen one in person.

Dino

Stradius011

Here's a link that shows you how you sex mollies and swordtails and guppies and platies. http://www.fishlore.com/Forum/99-sex...bearers.0.html

Izabela

Perhaps the fish was just very young when you bought it. I know my black fry were not completely black when very yound...some of them still have silvery bellies, but are slowly turning all black, like their parents. The sex, I'm not sure, perhaps same thing....

Izabela

guppygranny

I tend to agree with Izabella, that the specimen you bought was probably a robust young male who has just reached maturity. However as it has been observed in swordtail society and I know of several marine species in which the dominant female in a school of all female will change sex. It is very possible that your fish changed sex if the environment warranted it. Nature finds a way. Hope he makes lots of babies for you! Grannyguppy

armadillo

I've read articles about this, and they all concluded that the sex change cases were in fact misidentification of the gender of the young fry.

plecolover

yes one of my mollys used to be more of a dalmation molly now shes more black than anything.

Radcliffe

I think anything is possible when nature is involved! My Molly fry have been odd, but they are healthy so I am not worried or anything. I have a lyretail silver Molly who looked pregnant when I got her, and she still looks pregnant. She has the biggest squared off tummy, and has grown to a healthy, friendly nearly 4 inches long. The odd thing is that she has never had fry. I haven't even seen her have a skinnier time, like she might have had fry and eaten them. I seem to have a perpetually pregnant shaped Molly, in spite of sharing a home with boy Mollys since April. She has a great personality and has never looked sick in any way, so I figure that is just what she is like.

The other odd Molly is one that was clearly a girl for the first 4-5 months, but turned out to be a super super late bloomer. Even though the fish is showing that it is a male, and chasing the females appropriately, the other males in the tank try to mate with it and it has a far more round belly than any of the other males.

Having seen these traits in my Mollys in just the 6 months I have had them, I wouldn't put it past other Mollys to change color or gender!

--R

armadillo

Oh funny, we've had that too. She's now black and white instead of white and black. Here's some pix.