If its a line it sounds like lateral line disease. If you've got it on your other fish and its just spots then it is probably ich. Try a freshwater dip then qt them. _________ 
55 Gal Glass, 10 gal sump, seaclone100 protein skimmer, 2 pc 65w 10k's, 2 pc 65w actinic, 2 4ft VHO 110w bulbs, 135lbs of live rock, livesand/aragonite mix, coral beauty, percula clown, blue and yellow damsel, peppermint shrimp, Skunk shrimp, coral banded shrimp, xenia, leather, zoas, star polyps, button polyps, frogspawn, hammer, leather, mushrooms, long tentacle anemone, turbosnails, astrea snails, hermit crabs and a featherduster. | 
