Possible Parasite?

[SnakeEyes27]

Please help ID. My clown looks to be passing something unusually large... The clown's been in the tank for approximately 3 weeks. He initially had no appetite but has been acting normal since. Is this just a XXL BM or is this a parasite leaving the body?

Thanks

Update:
When the clown passed it completely, i netted it to prevent it from settling in the tank but couldnt make much of it...

 

[Domboski]

Could be a parasite. Can't tell in the pics though. Is this a reef tank (i.e. Corals and other inverts)?

 

[SnakeEyes27]

yes, it is a reef tank.

Some additional info:
- The clowns have only been eating frozen mysis shrimp (it wont take flakes or pellets).
- Its regular waste is clinging to the large object it was passing (so the extension is not a tail)

 

[Domboski]

Maybe the food is too fatty for them. :scratch: You could also treat with Prazipro as a precaution. It will kill any worm parasites in case that is the issue.