Is this septicemia on yellow tang


New member
Recently spotted some reddish colour on my yellow tang's dorsal and lower fin, like bloodstains, similar but less vivid areas can be seen on the body and the area around eyes looks strange. Also fins seem to be "damaged" a little. Could reddish colour mean septicemia and would you recommend to try medication on this fish? since 2 days ago bloodstains on fins seem to fade to normal, still body stains preoccupy me.
I've tested water and don't find anything wrong with params, also, there have been no new species added to the tank for months now.
Also, tang's behaviour seems to be more nervous now, but his appetite is OK.
I managed to take a picture, hopefully it will help to diagnose this case.


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New member
Could be either septicemia or ammonia burn..testing is relative if you could list your results you would get better answers..acceptable range can bother some fish my tang happens to be my barometer..if he is pale or reddish something is up..hth

95% it is a water quality issue IMO


Premium Member
I have something very similair on my Yellow Tang and have been wondering what it could be. The Tang is about 10yrs old and is still eating but is not acting the same. The discolored are area is on the left side of its body up near the dorsal fin. I know its not a water qaulity issue because I tested everthing. 0 nitrates, 0 ammonia and po4 is .01 (with Hanna), Ph 8.2, temp 78, Salinity 1.025, Alk 9, CA 450 and Mg 1300. I also do a 10% water change weekly. Maybe he is just old?I will try and trap him and put him in QT.


New member
I say yellow tang looks exactly the same...we need jhemdal's expertise on that photo...hope he notices the thread...