i recently purchased a pair of wild macs from a lfs,when they arrived there were 4 males 2 females.the guy there quarintines all his for a week before sale .when i came back two males had been killed.the pair i purchased had really good color and were doing well at home from the get go.upon further inspection the males and the females right ventral fin is gone,i mean you can still see a little L bone sticking out but absolutely no fin.the lfs said they would trade me for another fish but there doing so well and have great color,there actually showing a little pre spawn behavior so i kept them.i feed them mostly frozen brine shrimp,and flake food.he also has a big chunk out of his dorsal fin.should i medicate them or leave them be and be patient.any advice is welcome thank you.