Nemopilema nomurai, Nomura's jellyfish (family Rhizostomatidae), is one of the largest jellyfish in the world with a bell diameter reaching up to 2 m and a weight of up to 200 kg, forming massive blooms in the seas of East Asia, particularly the Yellow Sea, East China Sea, and Sea of Japan. These blooms cause severe disruption to fisheries operations, clogging and tearing nets, and damaging aquaculture facilities. The species feeds on zooplankton and fish eggs and is harvested for human consumption in parts of East Asia despite its enormous size. Genomic data have been generated for this species and are available in public databases, enabling comparative studies of cnidarian evolution and ecology.