jar missing scale

[fish meat]

i just notice what looks to me like my jar is missing some scale. i think it might be some kind of parasite. hopefully i worng. he/she is 12" and eating, and behaving normally. should i be worry? i did a 50% wc and add salt.

 

[I<3fish]

Gimme some pics and describe if the area is reddened/sore or if it looks slimy or fuzzy

 

[Lupin]

There is no need for you to add salt. Water changes alone should suffice. Loss of scales can often be pointed out to injury caused by scraping on decorations or its attempt to chase a prey wherein it eventually collided into a decoration.