Marine angelfish are from the Pomacanthidae family which contains seven genera and about 86 species. There are freshwater angelfish or tropical cichlids (Pterophyllum) found in the Amazon.
The angelfish most divers see tend to be larger marine species from the Holocanthus and Pomocanthus groups rather than dwarf angels from the Centropyge group. The most important or defining feature of marine angelfish is the distinct spine or thorn that forms part of their gill covers. This characteristic is how they earned their Greek name, Pomacanthidae meaning cover and akantha meaning thorn.
Other body features include small mouths, relatively large pectoral fins and rounded tail fins. Some, like Arabian angels, have streamer-like extensions of the soft dorsal and anal fins. The largest species is the grey angelfish at around 60 centimetres while dwarf angels only reach about 15 centimetres. Smaller angelfish are easily confused with butterflyfish as they have a similar shape, but spot that thorn and you know you’re looking at an angelfish.
