Rhacostoma

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Rhacostoma
Rhacostoma atlanticum.png
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Hydrozoa
Order: Leptothecata
Family: Aequoreidae
Genus: Rhacostoma
L. Agassiz, 1850
Species:
R. atlanticum
Binomial name
Rhacostoma atlanticum
L. Agassiz, 1850

Rhacostoma is a genus of aequoreid hydrozoans. It is monotypic with a single species, Rhacostoma atlanticum. It has been reported from the Atlantic coastline of North America, Colombia, western and central Africa. [1] The polyp stage is unknown. [2]

Morphology

The medusae reach up to 30–40 cm (12–16 in) in diameter with the bell height 3–4 times less than the width. [1] Specimens found in the northern waters tend to be transparent, while those found further south are tinted pink. [3] The broad stomach gives rise to 80–100 non-branching radial canals. [1] Tentacles are slightly more numerous than radial canals and possess elongated conical bulbs. [1]

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References

  1. 1 2 3 4 Kramp, P. L. (1961). Synopsis of the medusae of the world. Journal of the Marine Biological Association of the United Kingdom40: 1–469. P. 210 The full text Archived 2011-09-30 at the Wayback Machine
  2. Bouillon, J., Gravili, C., Pagès, F., Gili, J. M., Boero, F. (2006). An introduction to Hydrozoa. Mémoires du Muséum national d’Histoire naturelle194: 1– 591, p. 277.
  3. Goodwin, G., Bogert, C. M., Gilliard, E., Coates, C. W. The Illustrated Encyclopedia of Animal Life. Odham Books, 1961, vol. 13, p. 1666.