sick corydora

[SonicMarauder]

today i was looking overseeing my fishtank after oceanography class as i always do and i noticed that my biggest bronze corydora didnt look like he was breathing and his dorsal fin was laying flat and he was pretty much lifeless and looked a little bloated.... thinking he was dead i went to catch him and he swam away but didnt go very far.. and is just laying on the bottom but what gets at me the most is that you can usually see him breathing as he chills on the bottom.... right now he just lays there slightly bloated and doesnt look like he's breathing... and ever so often he'll swim to the surface and take a quick splash at the surface... i included a picture although it does show much

sorry about the shine from the colombian red-blue tetra... he's a camera hog

 

[SonicMarauder]

okay i removed all the carbon from the filters and i used a tablet of jungle tank buddies parasite treatment........ about an hour later he started breathing with his gills again and i saw something i thought id never see...ever...........i saw bubbles come out from under the cory.. i know corys sometimes will get an air bubble from gulping from the surface. is it possible that my cory just had some gas and needed to cut the cheese?