Chromis ID

[mrbluewildcats]

I've had 5 blue/green chromis for a few months now, but one has turned quite a bit darker than all the others. The first three pictures are of him and the fourth is what all the other chromis look like. Is he just darker or a different type of chromis?

He doesn't appear to have the black running down the edges of his tail fin like the pictures I've seen of the blue reef Chromis, but his dorsal fin definitely is mostly black. Maybe a black axil?

 

[Sierra_Bravo]

Black Axil's will have a black spot on the anterior side of their pectorals that you can only see with the fin out. Seems as though your fish may have that. They also have a very subtle pattern on their packs that will fluoresce that the regular C. virdis lack. The line around their eye and from the eye to the mouth is slightly more bright as well compared side by side. I don't have any showing a dark tail and dorsal fin like yours does, however.

 

[mrbluewildcats]

I'll have to look more closely and see if he has the black spot on pectoral fin. Some places I've looked online say they won't develop that spot until they mature, but I don't know when that would be. He's about 2" long right now.