waz going on? I've got 3 black molly fry at the moment, about 21/2 weeks old, but growing like weeds. I noticed one doing a kangaroo impression across the bottom the tank , boing, boing! Then he swims around quite happily.
If it was just doing it once, then I guess there's nothing to worry about. (Just a kangaroo impression, maybe it saw one on TV ) But if it keeps doing it, then maybe its scratching itself, which would mean your water conditions are bad.
well, I've just checked my water readings - which I do every day at the mo, coz the tank is only about 4 weeks old.
ammonia 0.25 (been having problems getting it to stay at 0, but never goes above that)
Nitrite 0 ( has been for yonks)
Nitrate 8
My tank (6 1/2 gall) is a wee bit overstocked ) and waiting for delivery of a new 40 gallon tank
So, Ive been doing 10 - 15% water changes every day to help, as I have 4 platy fry as well and a wee hoover of poo regularly. Also watching feeding and don't give any food one day a week. (wasn't sure how long my wee guys could do without!)
I had a molly in a tank that was still cycling once, and it did some wierd behavior too. Funny swimming and such, I would probably chalk that up to the cycling, and try to get the cycle done as quickly as possible. IE: gravel from an established tank. You want that Ammonia to be converted to nitrite as soon as possible as fish can usually tolerate nitrite a lot better than ammonia.
Many people skip feeding their fish one day a week. Most fish can go at least a week with out feeding.
I had a fish that kept 'zoom scratching' himself on hard objects and I believe it was the onset of ich. It sorta looked like he was hopping... I'm not sure, I'd have to see your molly do the jumping....