Sexual dimorphism identification of Chelmon rostratus, the Copperband Butterfly,

[OrionN]

That is not a straight picture side way. The position of the pelvic fins tell me that the picture is taken from the side but also in front.
I do think it is a male. But I think he is very thin with obvious pinched dorsal area. Unless he is really eating well, I would not get him because he is so thin.

 

[OrionN]

Going after the aiptasia on the clam shell and one of the aiptasia got dislodged but not quite eaten

 

[OrionN]

Both are gaining weight and are very healthy, good eater. They mainly eat aiptasia now , and other fauna in the tank. I only occasionally feed them now.