An upward dive...

[Pysgodyn]

My pl*co was doing something bizzare last night...from being a rather boring sucker on the bottom of the tank, he went through a phase of literally "SHOOTING" to the surface and back down again - really quick...he did it about 6 times in about an hour. Is this normal?! He seems happy enough in every other way. My parameters are Ammonia - 0, Nitrite - 0, Nitrate - 10, Temp 26C

 

[Tolak]

It's normal. My large commons nail the crossbar & wack open the lid on a regular basis.

Tolak

 

[Pysgodyn]

REALLY?! Mine are commons too. The guy in the shop said he'd find them a good home should they grow too big for the one I could provide them with. They're tiny at the moment. He said it'd take them years to grow...should I have believed him

 

[Tolak]

If they are small, they should be good for a year in your 125l tank. The bigger they get, the messier they get. Plan on cleaning more & doing more water changes as they get older.

Tolak

 

[OohFeeshy]

My cories do that. Loony things... Actually, it only seems to be one or two of them that do it. Maybe they think they've got a labyrinth organ...

 

[Tokis-Phoenix]

Yes but corys do it when they need air because unlike other fish that can actually breath in water, corys actually have air-breathing lungs meaning they need to go up to the surface about every 30mins at least to breath; they are in fact a very ancient group of fish distantly related to the ones that eventually made it onto land hundreds of millions of years ago.
And yes i do believe the common plec thing is normal, but if the are doing it on a very regular basis i'd go check the water qualitys all good and well just to make sure its not causing them any discomfort.