Most likely ate a piece of gravel and could not digest it. It probably blocked his digestive tract. Did he stop eating or become more reluctant to eat towards the end of his days?
Yes, he did stop eating, but I never noticed a lump or him actually in the act of eating gravel. I feed him hikari floating cichlid pellets, with the occasional shrimp.
A bichir does not have a large digestive tract so even the smallest pebble digested may have caused this without notice. I hope that this helps. A 10" bichir probably has a tract somehere in the mm cattegory so imagine what a 1 cm pebblle can do to it.
I would like to help anyone and everyone I can with their problems. This is no problem to me and I would just like to be updated on what you find. I would love some feedback. Good luck and once again I am sorry for your loss.
Your welcome. I would like to be able to help anyone and everyone with their inquiries about fish and I try to help to the fullest of my ability. Please be aware that I may be wrong, this is just an opinion. I would love to hear some updates on the situation and I would love same feedback.