My 6" motoro has something bloated sticking out of it under side. Could it be bloated intestines? or the Yolk sac please help.
This is fairly common and is often caused by over feeding,particularly in pups, some rays just don't know when they are full.
What you are seeing is a prolapsed anus, this will return to its normal position but you must stop feeding for a couple of days or so, once it returns feed far more sparingly for the next few weeks till the muscles tighten up again.
Don't panic it will be ok, would be better on a glass bottom, the internal organs are soft and not designed to make contact with abrasive surfaces.