Dempsey Doing Headstands

[Fishin Pole]

I have a 10 inch Jack Dempsey in a 75 with a few other fish......As of Friday, he started standing on his head in the tank, it seems to me to maybe be an air bladder issue.....Any ideas what could be causing this?......He can swim straight and he is still actively eating, but when he stops he takes a headstand position, like he wants to feed from the substrate...All my water parameters are fine:
Ammonia..........0
Nitrite.............0
Nitrate............10
Ph............7.2
Temp..............78

Should i quaratine him?...........In all my years of fish keeping i never seen anything like this..........Has anyone seen this happen to any of there fish and what was the end result?.......I have no idea what to do with him...........Other than standing on his head, he seems fine......Any feedback will be appreciated

 

[england]

Could be a swim bladder issue or it could be constipated, what do you feed it?
Do you ever use deshelled peas

 

[Fishin Pole]

I feed him a varied diet of Hikari Cichlid gold pellets, Hikari Cichlid Bio Gold pellets, krill shrimp and occasionally rosy red minnows...(Havent fed him live food for a month, though)......I havent varied his diet at all recently.....He does on occasion eat the algae wafers i feed the pleco in there with him.........I find this really baffeling, i never seen anything like this

 

[juanveldez]

surprisingly enough this isnt' the first time I have seen or heard of this. my old JD used to do the same thing, and as quickly as he started doing it he stopped doing it one day. I think that it will pass in time just keep an eye on him

 

[Fishin Pole]

Well Thank you for your input.........This had me scouring the internet all weekend long looking for an answer to his actions........He seems healthy in every other way, except this headstanding deal.............I guess i will try to see if he will eat de-shelled peas, if its constipation that will help