hard to say, I was pretty sure it was coming out of the gills, there is nothing visible now. behavior is normal, all fish eat hungrily. they all do hide a lot but its not very comfy in my quarantine tank and there is a lot of chasing around so that doesn't seem abnormal. if it helps it looks like my smaller male has a little white spot that has been on him since I got him. I have already done a round of api general cure on this tank because one wasn't eating (didn't recover, died shortly after starting treatment) should I try another round of medication?gill plate or coming out of the gills? Could be anchor worm, but really hard to say from the picture
also could be a leech etc
sorry you lost the one. pretty sure general cure will touch leeches or anchor worm
has anyone used seachem paraguard? I know I can get that locally, don't know about mardel products or tetra parasite guard. according to the seachem website "ParaGuard™ employs a proprietary, synergistic blend of aldehydes, malachite green, and fish protective polymers that effectively and efficiently eradicates many ectoparasites on fish (e.g. ich, etc.) and external fungal/bacterial/viral lesions (e.g., fin rot)."You will need Tetra parasite guard, Mardel Coppersafe, or Mardel Clout for anchor worm.
Clout will also take care of leeches.