I recently brought home a fat head bichir (Poly. Weeksii) into a tank with a almost exactly the same sized buettikoferi (Poly. Palmas Buettikoferi) and a syno schoutendeni. The fat head has been eating well but it looks like he (I think) was warring with the other two bottom dwellers for space and has a slight tear in one of his pectorals. What is more worrying is that under one of his gill coverings he has something poking out that doesn't look like a fluke, but almost like a single external gill poking out. He didn't have this earlier and is well above the size where his external gills should have receeded. The fish is still behaving totally normally and I can't find any information on large parasites such as that. Any insight would be much appreciated.