Red Gill's On A Fish?

[gh74]

This evening there i noticed the gill's on one of my fish is red with like 2 wee red dots above each gill,tested my water and all my stats are all as expected they should be,what can it be,just wouldnt like to loose him

 

[bluesword23516]

What is the size of the tank, the breed of fish, and its tankmates? 

 

[gh74]

Hi Bluesword
 
Its an albino shark,its a lido juwel 200 litres hes not that big,
 
guppies,neons,bala shark very quiet,mollies platys,silver dollar,pictus,tetras,gourami

 

[bluesword23516]

Do you see the gourami or the other shark chase it?  It could be injured.  How is he doing today?