vertical tilting molly behavior with new dalmation lyretail

[RJ23]

Hi all..

I've had a group of black mollies (1M/2F) in my tank for a while now and the two females really have been the bosses off the tank. They were getting a bit territorial sometimes as well (I think one is currently preggo, distended belly)

I've read that adding additional female mollies can help curb aggression so I saw this beautiful young lyretail dalmation at my LFS. I know the fish are always great from this store because he won't sell fish in the first 7 days he gets them and always loves to chat about what's going on with each customers set up. His store has been in operation for 40+ years I'll upload some pics of the crazy tanks he has sometime soon.

Anyway back to the topic.. I've noticed that the aggression has subsided in large part since introducing the new female, but one strange thing I've seen is the mollies on many occasions have engaged the lyretail and gone into a prone-line position with their nose straight up and lettimg themselves float that way for a few seconds underneath her.

Is this a posturing or submissive type move? The dalmation even though she's young is bigger than the two females who were ruling the roost beforehand. The mollies otherwise seem very healthy other than this strange behavior.

Ammonia - 0 PPM
Nitrite - 0
Nitrate - 5.0

I couldn't manage to capture the behavior .. but here's a look at the lyretail dalmation molly

Thanks for any thoughts on this

 

[RJ23]

Anyone seen this before? They are still doing it.. putting themselves mouth up and letting themselves float for a second or two vertically. They only do it near the dalmation.

 

[H2OJO]

The only time I have seen any live bearer do this is when they are either pregnant or sick. Keep a close eye on them. I can't really see from your pics whether they are large bellied but face down tail up isn't good.

 

[RJ23]

The only time I have seen any live bearer do this is when they are either pregnant or sick. Keep a close eye on them. I can't really see from your pics whether they are large bellied but face down tail up isn't good.

It's actually the opposite, tall down face up. I'm pretty sure one of the females is pregnant but I saw both of them do it.I will keep an eye on it and try to post a pic of the pregnant one.

 

[RJ23]

Here's the most aggressive female molly.. i think its because she's pregnant? Didn't see the nose up floating behavior today near the dalmation

 

[H2OJO]

Here's the most aggressive female molly.. i think its because she's pregnant? Didn't see the nose up floating behavior today near the dalmation

She doesn't look pregnant at all.

Molly's are a bit like Platys in that the way they do the deed, so the positioning isn't anything to do with sexual behaviour.

It may well be a challenging prone, but I highly doubt it. Is she healthy in all other aspects and swimming healthily?

 

[Samzter]

The black one seems to look pregnant.