I'm new here and joined up due to an issue with my Black. I have had him for a little over a year, bought him when he was ~1.5 inches long, he's about 2.5/3 inches long now.
He is in a 75g tank, sand substrate , several mossimo balls and some large rock decor for hiding spots.
Water stays at 78 degrees, water quality parameters are damn near perfect. pH is around 7/7.1....0 ammonia, 0 nitrites, nitrates are around 20ppm . I do weekly 20/25% water changes/addition using the python water tube.
Filteration is a hang on back Marina system for a 75g tank, internal canister power head with a filter, and most importantly, fluval 306 that works magic.
His diet is raw thawed shrimp, tilapia, and very occasionally- like once every 6 weeks or 2 months, some salmon bits.
About a month and a half ago, I noticed his mouth remained open. I didn't think anything of it but it got worse and worse. He was still eating fine, just had more difficulty with it. Over the last week, he tries to eat the food but doesn't seem to be able to grab it and swallow it. This is concerning me.
He remains VERY active and will swim sharply to ththe tank when it's feeding time.
I have noticed one of his gills is slightly swollen and you can some red in it- tried to capture this in the pics below. His eyes appear normal,
I don't think anything is lodged in his mouth but not quite sure. I figured if something was lodged it would have been worked out by now, as this has been a long time now.
Any ideas what this could be? Would a disease cause this possibly? I am not sure what to do but now that he can't get food down, I'm getting very worried. Again, he is not sluggish and remains very active, but his mouth is literally wide open....