The Scyphozoa are a somewhat uniform but ancient group, comprising probably fewer than 200 species world-wide. Many of the extant genera, and in some cases even the species, are markedly distinct from their closest relatives. There are only a few genera of several confusingly similar species. Nevertheless, because many species are large and conspicuous, occurring primarily near the coast, repeated redescription and consequent taxonomic confusion has hampered taxonomic understanding. What follows is probably the first reliable list of European species. Within the present lists, the Stauromedusae were checked by Dr Yakko Hirano, the Coronatae by Dr Gerhard Jarms, and the remainder by Dr Paul F S Cornelius.
The most helpful monograph is F. S. Russell’s (1970) superb treatise. A key to world genera was published more recently (Cornelius, 1997). Most, but not all, are shallow-water coastal species. However, Pelagia is open-ocean planktonic, and Stygiomedusa and Deepstaria are deep-water forms. Scyphomedusae are most speciose in the tropics. All major divisions are represented in Europe though few rhizostomes extend north of the Mediterranean Sea. One, Europe’s second largest invertebrate, Catostylus tagi, occurs in the Tajo estuary near Lisbon and from there southwards along the African coast, though the almost as huge Rhizostoma octopus is common at least as far north as southern Scotland and may exceptionally occur in Norwegian waters. The semaeostome Cyanea capillata may grow to approximately 2m diameter in continuous arctic daylight. A useful paper by Galil, Spanier & Ferguson (1990) describes and illustrates some immigrant species occurring in the Eastern Mediterranean. Of the Stauromedusae there is perhaps no European guide. NW European species were nicely summarised by J S Ryland (in Hayward & Ryland, 1990 (detailed), 1995 (abridged)). The European list that follows here was extracted by J. van der Land from a world list prepared by Dr Y. Hirano. A manuscript translation into English of the Stauromedusae section of the important book by Naumov (1961) is held in the library of the Natural History Museum, London.
- Cornelius, P. F. S., 1997. Keys to the genera of Cubomedusae and Scyphomedusae (Cnidaria). Proceedings of the 6th International Conference on Coelenterate Biology (1995). J. C. den Hartog. (ed.), Leiden, National Natuurhistorisch Museum, 109-122.
- Cornelius, P. F. S., Manuel, R. L., & Ryland, J. S., 1990. Cnidaria. In: Hayward, P. J. & Ryland, J. S. (eds) The Marine Fauna of the British Isles and North-West Europe. Volume 1. Introduction and Protozoans to Arthropods. Oxford, Clarendon Press, pp. 101-180. [includes stauromedusae, no other scyphozoans]
- Cornelius, P. F. S., Manuel, R. L., & Ryland, J. S., 1995. Hydroids, sea anemones, jellyfish, and comb jellies. In: Hayward, P. J. & Ryland, J. S. (eds) Handbook of the Marine fauna of North-West Europe. Oxford, Oxford University Press, pp. 62-135. [abridged edition; includes both stauromedusae and scyphomedusae.
- Galil, B. S. Spanier, E. & Ferguson, W. W., 1990. The Scyphomedusae of the Mediterranean coast of Israel, including two Lessepsian migrants new to the Mediterranean. Zoologisches Mededelingen 64, 5-105.
- Naumov, D. V., 1961. Stsifoidnye meduzy morei S.S.S.R. [Scyphomedusae of the seas of the U.S.S.R.] Fauna S.S.S.R. 75, 1-98.
- Russell, F. S., 1970. The medusae of the British Isles. II. Pelagic Scyphozoa with a supplement to the first volume on hydromedusae. Cambridge, Cambridge University Press, pp. xii, 284.