We've recently gotten some mollies, and I have a few questions.
We have a 33gal tank that's been running now for almost 6 months. Lots of live plants.
Current population is a cherry barb, half a dozen neons and 4 mollies. Not sure if their colouring makes a difference, but there's one bright orange, one pure white, one dalmation and one that's a kind of brown with white "freckles".
First, I'm wondering how to tell whether they're male or female? I asked the fish guy to try and get some of each, but I wasn't really paying attention when he told me what they are because I had 3 kids with me at the time
I'm not particularly interested in breeding them on purpose, as we don't have a separate tank or anything to stop any babies from getting eaten :( but if they get pregnant, I'd like to know how to tell so the kids can experience the process.
Second, is it normal for mollies to swim straight up and down? I've tried to do some googling, and have seen "swim bladder" thrown about, but always with the fish swimming nose down. Mine seem to do a strange nose up swimming. They'll all do it for a second here and there, but the dalmation will hold itself like that for a full minute or more. Even more oddly, it usually does this in the early evening, shortly after I turn the tank lights on. They otherwise seem healthy, swimming together, eating ok.
Lastly, and I suspect this is fairly normal around fish, but I've honestly never had a fish do this before. The orange molly quite often will splash around at the top of the tank. It'll be swimming around like normal, then suddenly spaz out and start flopping/jumping/splashing (?) around at the top of the water. It's quite comical to watch, actually. Just not sure if they're supposed to act like that?
Thanks so much for any input, guys!