Male sailfin undeveloped sail?

[Elisabeth83]

I bought 6 sailfin mollies the other day. 2 are dalmation ones I thought were a pair. I didn't even really check male and female I just went by their sailfins. Well while looking at my supposed to be dalmation female today I noticed she has a gonopodium Thing is HE doesn't have a high sailfin at all. He looks exactly like a female..same size same finnage just he has a gonopodium. So what's going on here? Has he not developed fully for some reason? Do I have a normal molly? I wouldn't think that it's a normal molly seeing as it's really big. I've seen older big normal mollies but you can kind of see it in her finnage and face that they are old. This one looks young. The normal older big ones I've seen also were big females I haven't seen a really big male.

These are the 3 explanations I have
Mixed gender
Undeveloped male
or an old huge normal male molly

 

[nmonks]

Hi there --

My understanding is there are a couple of factors re: sailfin size in mollies.

One is that only some species have them. Since the "fancy" mollies, as I understand it, are all hybrids, you never really know quite what genes are likely to surface. You can play a probability game once you've bred a few generations at home, but just buying them from a shop is unpredictable. Certainly black mollies, for example, are hybrids that sometimes have small sailfins and sometimes have regular dorsal fins.

The second factor is environmental: mollies raised in crowded tanks are (so I've read) likely to remain small and not fully develop the sailfin. This factor affects the fry rather than adult fish, so by the time you've bought them, the damage has been done.

Hope this helps,

Neale

 

[Tokis-Phoenix]

Standard molly males have quite small sailfins and the only realy difference between them and other female mollys is the obvious difference in sexual organs/fins, it could also be he is undeveloped due to enviromental factors/stress or he has poor genes or is a mutant but these are less likely. Its also posible you have a jumbo male platy(these are usually the result of hybridizing platys and swordtails) like if he's a non molly color like red or has traces of the defining mickey mouse platy tail pattern he's definatly a jumbo platy.
Can you get a pic of him?

 

[Elisabeth83]

I am now just thinking he just had an undeveloped sailfin. Both my males were chasing him..they don't chase eachother but they didn't like this guy Anyways I had called the pet shop and they said I could bring him back. He was a dalmation molly and I bought him and the other guy to be a pair so I didn't want to keep him. I'm now on the lookout for a female dalmation sailfin molly

Anyways when the guy at the shop released him back into the tank he flared his fins and you could see his sailfin was higher than the females in the tank so I guess it's been growing. Maybe he supressed growing or something? Like was in a tank with so many males he just didn't develope?

That's all I can think of as he was certainly a male and was certainly a sailfin molly as he was dalmation colored and I've never seen a platy or swordy that looked like that. His sail must of grown while I had him though but because my 2 males were chasing him he never really flared so I couldn't tell that it had grown since I bought him. I don't know how much a sailfin can grow in 3-4 days but it did. Maybe good water conditions, less stress and good food?

It was sad to see him go but I couldn't keep 3 males and I really want a pair (male,female) of the dalmations ones