Acanthaster is a bitypic genus of large and venomous starfish placed in its own family, Acanthasteridae.

Acanthaster are native to coral reefs in Indo-Pacific region.

[2] The species in this genus are a contributor to coral reef degradation because they prey on a large amount of live coral at high density.

[2][3][4] These species are listed in the World Register of Marine Species:[1] Some sources add Acanthaster ellisi, (Gray, 1840) but it is now considered as a subspecies of A. planci in the eastern Pacific.

Haszprunar, Vogler & Wörheide (2017)[6] suggest to split "A. planci" in :