Phoenix Tetras are a vibrant fish with a grey silvery body, and their body also has a delicate gold colored sheen. Their fins have a beautiful red coloration with white extensions that look very ornate. Mature females are noticeably more stocky than the males are. The males have longer filaments on their fins, and they show off a flashy bright red color. The caudal fin is translucent in color in the female Phoenix Tetra. Mature male Phoenix Tetra have elongated dorsal and anal fins. These differences make it easy to distinguish male Phoenix Tetras from females.