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Biology/Natural History: Abundance of this species varies widely seasonally and from year to year. Females of this species carry young larvae on the inner edges of the oral arms. Scyphistomae can sometimes be seen in large numbers attached on floating docks or on protected rocks in the lower intertidal, and are about 1 cm long when extended, with long tentacles. In central CA the scyphistomae are seen beginning in February and strobilate around March. In Washington they strobilate January to April (Purcell et al., 2009). The medusae grow rapidly and are sexually mature by June. Most medusae die after reproducing but some live a second year. Polyps (scyphistomae) feed by predation like small anemones. The medusa feeds by capturing small organisms such as copepods on mucus, which is then moved to the mouth by cilia. The medusa seems to make little use of nematocycts in capturing food. Individuals of this species from cold waters can survive being frozen solid in ice. The species appears to migrate toward the surface during the day and downward at night. The umbrella pulsing originates in one of the eight rhopalia, and spreads via the nerve net. When starved, this species can shrink dramatically in size while retaining functionality. The tentacles of this species may trigger a slight rash. The species is sometimes eaten by blue rockfish Sebastes mystinus.