My marble molly's swim funny...?

Question

I have other fish in there and they swim normal...not wobbly. My two molly's shake a little I haven't noticed it before but I have to look closely to really see it. My ph and ammonia levels are safe, filtration is good, and all the other fish seem great.
I just don't know if all molly's are this way or just mine....I would think they had a little stroke...if that's even possible for fish....any help?
Also, my Molly's, guppies, and platy's nip at the tank ornaments and then quickly rub their body over the smooth parts, it looks like their way of cleaning or itching themselves, it's kinda cute...should I be worried about that?
thanks a bunch.

Answer 1

First, the funny swimming is probably just something called shimmies, or livebearer disease. It's very common in livebearers that are kept with little or no salt in the tank and really isn't a disease exactly, just related to the salt content of the water. 1 teaspoon of salt per 5 gallons will fix the shimmies basically overnight.

The rubbing or scratching you are seeing is cause for worry. Fish do this when their skin is irritated. It could be from excess ammonia in the tank, or could be from a parasite.

Check your ammonia and do a water change if it's high. Also look over your fish for any white spots, excess slime coat or any discoloration. All of those are signs of parasites. If you see any of that at all be ready to treat the tank for parasites. Any of those smaller parasites can be treated with Maracide. Just follow the directions on the bottle and you should clear that up in about a week or two, depending on the parasite you have.

If I can help further feel free to email me

MM

Answer 2

if the fish is shimmying, the fish is sick. shimmying is a short forward & reverse action, like they can't figure if they wanna go ahead or back.
I'm not sure the cure but add salt to the tank. Mollies do well in brackish water; this may be the cause. I had a huge nearly black dalmation sailfin mollie who shimmied once until I added sea salt. get it at the fish store.