Many species of fish can be used in a reef aquarium tank. The most common fish found in an aquarium tank are centropyge (angelfish), amphiprion (clownfish), dragonnettes, mandarinfish, gobies, tangs or surgenonfish, among others.
The common rule of thumb when integrating fish into a reef aquarium is to understand that reef tank creatures are survivors by nature and not all fish will live in harmony and that you may have to remove certain fish that are harming the coral or other inhabitants of the tank.
Centropyge, known as angelfish, are generally a good choice for reef aquariums, especially larger tanks. There are a number of centropyge varieties. The genicanthus melanospilos (Japanese Swallowtail Angelfish) is known for its gentle nature and as a fish that will not disrupt corals or invertebrates. Some common types of centropyge include centropyge bispinosus (Coral Beauty Angelfish), Centropyge fisheri (Fisher’s Angelfish), Centropyge loriculus (Flame Angelfish), Centropyge flavissimus (Lemonpeel Angelfish), Genicanthus personatus (Masked Angelfish), Centropyge multicolor (Multicolor Angelfish), Centropyge eibli (Orangelined or Eibl’s Angelfish) and Centropyge potteri (Potter’s Angelfish).
Amphiprion, otherwise known as clownfish, are also a common fish in reef aquariums. The Amphiprion ocellaris is considered an excellent choice for reef aquariums. Their vivid orange color with characteristic white striping makes them a recognizable fish among reef aquariums. Most amphiprion make good choices for reef aquariums perhaps with the exception of Maroon Clownfish that can grow very large and act aggressively.
The algae eating creatures, gobies, are also safe for reef aquariums. They also usually eat amphiphods and copepods. Gobies are usually categorized in three groups: sand sifting gobies, shrimp goides and small gobies. Some of the common sand sifting gobies are Valencienna puellaris (Diamond Watchman Goby), Engineer Goby (Pholidichthys leucotaenia) and Amblygobius decussates (Orangemarked Goby). Among the shrimp gobies there are lots of species including the rarely aggressive Amblyeleotris diagonalis (Diagonal Bar Prawn Goby) and the passive Stonogobiops nematodes known as a Blackray Shrimp Goby. There are many different species of small gobies, as well, and they are known for not interfering with the invertebrates. Some common species are Elacatinus horsti (Gold Line Goby), Gobiodon okinawae (Yellow Clown Goby) and Paragobius lacunicolus (Panda Clown Goby). Small gobies come in a multitude of colors and are mostly bullet-shaped smaller fish.
Another algae-eating fish that are great for reef aquariums are surgeonfish, known as tangs. They are herbivores by nature so they will also not eat the corals or invertebrates. They can grow to be pretty large, which makes larger tanks a better fit for them. Tangs are very bright and colorful fish. There are dozens of tang species and some of them include Acanthurus Achilles (Achilles Tang), Paracanthurus hepatus (Pacific Blue Tang), Acanthurus lineatus (Clown Surgeonfish), Zebrasoma xanthurum (Purple Tang) and Ctenochaetus hawaiiensis (Chevron Tang).