Trachymedusae Haeckel 1866
Description
Order Trachymedusae Haeckel, 1866 Diagnosis
Hydromedusae with umbrella margin entire, not deeply-lobed; with conspicuous marginal nematocyst ring; manubrium with or without gastric peduncle; with circular and radial canals, and gonads usually conFned to the latter; centripetal canals either present or absent; tentacles marginal, either solid, or solid and hollow occurring simultaneously; statocysts of ecto-endodermal origin, either free or enclosed; velum generally well-developed, exceptionally absent.
RemarksThe diagnosis given above combines those provided by Kramp (1968) and Bouillon et al. (2006), and adds the case when the velum is absent, as it will be shown below for the genus Glaciambulata gen. nov.
The taxonomic status of some of the families included in Trachymedusae is unsettled yet. For example, Collins et al. (2008) have shown that the family Geryoniidae Eschscholtz, 1829 is derived from within another order, Limnomedusae Kramp, 1938, and the family Halicreatidae Fewkes, 1886 belongs to a sister group of a clade containing the orders Narcomedusae Haeckel, 1879 and Actinulida Swedmark & Teissier, 1959, as well as the trachymedusan family Rhopalonematidae Russell, 1953. In addition, according to the same source, some characters of the family Petasidae Haeckel, 1879, especially the presence of 4 radial canals instead of generally 8, common to Rhopalonematidae, suggest that it may belong elsewhere.
Notes
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Linked records
Additional details
Identifiers
Biodiversity
- Kingdom
- Animalia
- Order
- Trachymedusae
- Phylum
- Cnidaria
- Scientific name authorship
- Haeckel
- Taxon rank
- order
- Taxonomic concept label
- Trachymedusae Haeckel, 1866 sec. Galea, Roder, Walcher, Warmuth, Kohlberg & Fischer, 2016
References
- Kramp P. L. 1968. The hydromedusae of the PaciFc and Indian Oceans. Sections II and III. Dana Report 72: 1 - 200.
- Bouillon J., Gravili C., Pages F., Gili J. M. & Boero F. 2006. An introduction to Hydrozoa. Memoires du Museum national d'Histoire naturelle 194, Museum national d'Histoire naturelle, Paris. http: // dx. doi. org / 10.1086 / 586983
- Collins A. G., Bentlage B., Lindner A., Lindsay D., Haddock S. H. D., Jarms G., Norenburg J. L., Jankowski T. & Cartwright P. 2008. Phylogenetics of Trachylina (Cnidaria: Hydrozoa) with new insights on the evolution of some problematical taxa. Journal of the Marine Biological Association of the United Kingdom 88 (8): 1673 - 1685. http: // dx. doi. org / 10.1017 / S 0025315408001732
- Haeckel E. 1879. Das System der Medusen. Erster Theil einer Monographie der Medusen. Mit einem Atlas von vierzig Tafeln. Gustav Fisher, Jena. http: // dx. doi. org / 10.5962 / bhl. title. 46856