Eric Walker added A sleep-like state in Hydra unravels conserved sleep mechanisms during the evolutionary development of the central nervous system | Science Advances to Hydra (genus)

Eric Walker added Sleep Evolved Before Brains. Hydras Are Living Proof. to Hydra (genus), Sleep and Upside-down jellyfish

Eric Walker added Hydra (genus) - Wikipedia to Hydra (genus)

Eric Walker added a number of links to Hydra (genus), and added Hydra (genus) to Hydridae

Eric Walker added Hydra (genus) to Hydridae, and added Hydridae to Anthoathecata