Dalamation Sailfin Mollie

[Hoppo]

One of my Dalamation Mollie's is being aggressive to my other Dalamation mollies. This one has a huge beautiful sail, while the other 2 are just regular. Come feeding time, it will chase the other 2 from the food. Any reason for this?

 

[OldMan47]

Hi there Hoppo.
Any fish will exhibit its full dominance in any situation. It seems that the sailfin is being accepted by the other fish present as a sign of its dominance. That means that the sailfin looking fish will get the best of everything in your tank simply by the other fish accepting it. It sounds to me as if the fish in your tank understand the privileges of dominance better than you do. The dominant fish is taking advantage of being dominant while the other fish have decided to allow that that one is indeed the dominant fish present.

 

[Hoppo]

Alright that makes sense. My wife said that one of the Platys was fighting back today. So I guess the Platy wasn't in the mood to pushed around tody.

Now will my sailfin mate with the other two if one is a male or female. I'm not even sure what the sex's are.

 

[-FighterFishh]

Alright that makes sense. My wife said that one of the Platys was fighting back today. So I guess the Platy wasn't in the mood to pushed around tody.

Now will my sailfin mate with the other two if one is a male or female. I'm not even sure what the sex's are.

If you try and get some pictures up we can tell you what gender they are
You'll need to make sure you know what they are else a lone female may be harassed to death.

 

[lilfishie]

This image should help you sex them, its the same for all common livebearers

 

[Hoppo]

ok, based on the diagrams, I believe the Sailfin is a Male and the other 2 are females. Not 100% sure on this. I'll try and get some pics up.

 

[OldMan47]

Why not have a look at the actual pictures of a male and female that we have pinned at the top of this section under the heading of gender determination? Sexing common livebearers is almost as easy as Lilfishie said, but people can be misled by the fin shapes of lyretailed fish of certain species. In some fish the lyretail gene causes so much extension of fin rays that some females are mistaken as males by less experienced people. The delta shape of a female still exists in them but the first ray of the anal fin of those females sometimes seems to resemble a gonopodium.

 

[fuzzynicki]

From your original description it def sounds like you have a male and two female sailfins. The males have a long, sweeping dorsal fin and the female fin is more of a 'standard' one. The male will chase the females round the tank trying to breed so hopefully you should have a few fry soon!

 

[Unknown10101]

The large sailfin molly is trying to mate with the females, so once you see that the females look fat and pregnant, you should put them in a seperate tank or a breeding chamber so they can give birth in peace.

 

[Neon Squid]

I have dalmation mollys in a community tank also. My male has a large sail-fin also and displays the same behavior to the females as yours does. He is the pushiest fish in the tank when it comes to feeding and being dominant but I find he tends not to do any damage to the other fish. He breeds with the female dalmations all the time despite the minor aggression. Wouldn't say there's much to worry about. You could try introducing some more females to keep him distracted but when I done this with mine it didn't change much.