Merder captured various ships and transferred them to his world. When Aquaman and Aqualad investigated, they two were captured. He manipulated the heroes into unleashing him on the larger Earth, where he  easily took control of all life in the sea. Aquaman found out this control could be broken by a strong jolt of electricity to the controlled animals. Â
Â
Merder was defeated in close-range combat and exiled back into his microverse. Some similarity in name and depiction to the later character Mordru has been noted but there is no in-story connection between them.
