I disagree with the consensus here that the pictured fish is that of a sp.44
The banding of the fish should be much more pronounced but the big "tell" is in the dorsal fin. The picture with the fish in the water exhibits a neon turquoise coloration which should be the same red hue in the male's tail. The operculum region should be much blacker and more solid.
The temperment of the sp.44 is nasty, they definitely would be picking on just one fish once established in your tank.
