Air sac inside aro's abdomen

[BOOMERANG]

the other day, my huge tanks broke, leaking all the water. i was able to transfer the remaining water together with all the filtering gadgets in my 48 x 21 x 21 tank. unfortunately, my aro didn't last long and it died this afternoon. since i want to find out what was inside the lump in his body, i cut him at the belly and i was surprised that the lump was caused by air sac inside, just above the anus. any idea what causes that air sac lump? i need to learn a lot of things before i get another one.
;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;(;( ;(;(;(;(;(
http://i386.photobucket.com/albums/oo308/PAULHDUMAN/aromar10-20a.jpg
http://i386.photobucket.com/albums/oo308/PAULHDUMAN/aromar10-20b.jpg
http://i386.photobucket.com/albums/oo308/PAULHDUMAN/aromar10-20c.jpg
http://i386.photobucket.com/albums/oo308/PAULHDUMAN/aromar10-20d.jpg

[Hendri]

our condolences

[BOOMERANG]

thank you. my wife who brought it home is very upset. i will try to get another one with a separate tank

[boyan]

our condolences...

[Kangga]

Sorry for your lost Bro...

[zac_7]

deepest condolences......