''Vampyrocrossota'' is a genus of hydrozoans of the family Rhopalonematidae.Thuesen, E.V. 1993. ''Vampyrocrossota childressi'', a new genus and species of black medusa from the bathypelagic zone off California (Cnidaria: Trachymedusae: Rhopalonematidae). Proceedings of the Biological Society of Washington 106 (1): 190-194. http://biostor.org/cache/pdf/a3/f3/cc/a3f3cc72a73958a5bc0da92920424458.pdf The genus only contains one species, ''Vampyrocrossota childressi''. Unlike many

hydromedusae Hydrozoa (hydrozoans; ) are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialized ...

, these animals do not have a

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

stage. Rather, they spend their entire lives in the water column as plankton. It is the only known species with a medusa that is truly black.

Distribution

''Vampyrocrossota childressi'' has only been found in the Pacific Ocean off California and British Columbia.Thuesen, E.V., 2003. ''Crossota millsae'' (Cnidaria: Trachymedusae: Rhopalonematidae), a new species of viviparous hydromedusa from the deep sea off California and Hawaii. ''Zootaxa'', 309: 1-12 http://www.mapress.com/zootaxa/2003f/zt00309.pdf This deep-sea animal lives between 600–1475 m depth.

Etymology

This species was named after James J. Childress, a marine biologist at the University of California, Santa Barbara who helped discover this jellyfish.

References

Rhopalonematidae Monotypic cnidarian genera {{hydrozoa-stub