The Black Sea Cucumber (Holothuria atra) and the Crown of Thorns Starfish (Acanthaster planci) from Enggano Island are marine organisms that have secondary metabolite compounds potentially exhibiting antioxidant activity and toxicity. This research explores the antioxidant activity and toxicity potential of these two Echinodermata species, H. atra and A. planci. The DPPH method is used to deter…