Neoglyphidodon melas. The Blue Fin Damsel (Neoglyphidodon melas, formerly Paraglyphidodon melas) is characterized by a white body and yellow top, with blue and black pectoral and anal fins. As they mature, their coloration becomes much darker, and will eventually become an almost uniform dark grey. Damsels and chromis both come from the Pomacentridae family, which they share with Clownfish, a close relative and another very popular group of aquarium fish. Their temperament can range from very peaceful to quite aggressive and territorial. Chromis (fish from the genus Chromis) tend to be more peaceful than the rest but can also be more delicate. Other common genuses of damsels include Amblyglyphidodon, Chrysiptera, Dascyllus, Neoglyphidodon, Pomacentrus, Stegastes and others. These fish are generally not picky eaters. In the aquarium, they will usually feed on flakes and pellets but should also be given fresh or frozen algae and meaty foods like brine shrimp, mysis shrimp, planktons, krill, shrimp, scallop and similar items. Damsels can become very territorial as they become established in the aquarium. Some species will defend their territory especially aggressively; use caution when stocking the aquarium since their small sizes can be deceiving; mature or established damsels may pick on smaller or weaker fish or on new arrivals. Some damsels retain the same appearance throughout their entire lives while others undergo a radical color change as they mature from juveniles to adults. A few may get more colorful as adults but most change from very colorful juveniles to bland, more subdued adults. Visit That Fish Blog for more information from our marine biologists on clownfish and damselfish and many other aquarium-related topics!