Helmet jellyfish

Common card · No. 391978

The helmet jellyfish (Periphylla periphylla), sometimes called the merchant-cap, is a luminescent, red-colored jellyfish of the deep sea, belonging to the order Coronatae of the phylum Cnidaria. It is the only species in the monotypic genus Periphylla and a rare example of a scyphozoan with a polyp-less life cycle, occurring exclusively as a medusa. Periphylla is intensely photophobic, and thus only seldom leaves the bathypelagic zone (likely only on particularly dark nights).

Read on Wikipedia · Image Edward Adrian Wilson (1872 -1912), Public domain