Hydrozoa

Rhizophysa, copyright L. Madin.

Belongs within: Medusozoa.
Contains: Limnomedusae, Narcomedusae, Trachymedusae, Halammohydra, Thecata, Capitata, Filifera, Codonophora.

The Hydrozoa is a group of cnidarians ancestrally exhibiting a life-cycle alternating between a medusoid and a polypoid phase, though one or the other of these phases has been lost in a number of derived subgroups. They may be divided between the Trachylina, in which statocysts are of ecto-endodermal origin, and Hydroidolina, whose statocysts (if present) are of ectodermal origin (Daly et al. 2007).

Characters (from Daly et al. 2007): Gametogenic tissue usually of ectodermal origin and location. Medusae, if present, possessing velum and two nerve rings; budded laterally from polyps. Polyps, if present, lacking septae.

Hydrozoa [Craspedotae, Hydroida, Hydroidomedusae, Hydromedusae]
    |--Trachylina DB07
    |    |--Limnomedusae DB07
    |    |--Narcomedusae DB07
    |    |--Trachymedusae DB07
    |    `--Actinulida [Halammohydrida, Halammohydrina] DB07
    |         |--Halammohydra DB07
    |         `--Otohydra Swedmark & Teissier 1958 CS-P86 [Otohydridae DB07]
    |              |--O. tremulans Lacassagne 1973 CS-P86
    |              `--O. vagans Swedmark & Teissier 1958 CS-P86
    `--Hydroidolina DB07
         |--Thecata DB07
         |--Anthoathecata [Anthomedusae, Athecata] DB07
         |    |  i. s.: Gemmaria McCrady 1857 H04, RL03
         |    |           `--G. sagittaria H04
         |    |         Tiara pileata H04
         |    |         Stomotoca pterophylla H04
         |    |         Thamnostylus dinema H04
         |    |--Capitata P79
         |    `--Filifera P79
         `--Siphonophorae [Physophorae, Physophorina, Siphonantha, Siphonophora] DB07
              |  i. s.: Diphyopsis B26
              |           |--D. dispar B26
              |           `--D. major B26
              |         Anthophysa formosa B26
              |--Codonophora DPH05
              `--Cystonectae DPH05
                   |--Epibulia ritteriana H04
                   |--Cystalia monogastrica H04
                   |--Salacia polygastrica H04
                   |--Physalia [Physaliidae] DPH05
                   |    |--P. pelagica C45
                   |    `--P. physalis (Linnaeus 1758) [=Holothuria physalis] DB07
                   `--Rhizophysa [Rhizophysidae] DPH05
                        |--R. eysenhardti DPH05
                        `--R. filiformis DPH05

Hydrozoa incertae sedis:
  Rhabdohydra tridens BU02
  Chaunograptus Hall 1883 BU02, B70 [Chaunograptidae]
    `--*C. novellus (Hall 1883) [=Dendrograptus (Chaunograptus) novellus] B70
  Conchopeltidae [Tetradialomorpha] IF02
    |--Conchopeltis Walcott 1879 KC60
    `--Conomedusites Glaessner & Wade 1966 IF02, G79
         `--*C. lobatus Glaessner & Wade 1966 G79
  Heterastridium Reuss 1865 [Heterastridiidae] SG-M98
    `--*H. conglobatum Reuss 1865 SG-M98
         |--H. c. conglobatum SG-M98
         `--H. c. disciforme SG-M98
  Plumaria undulata B79
  Stephanidium H15
  Perigonimus cidaridis BK77
  Cuspidella BK77
  Distichopora violacea VV77
  Radiotrabeculopora Fan, Rigby & Zhang 1991 (see below for synonymy) RLS04
    |--*R. xiangboensis Fan, Rigby & Zhang 1991 RLS04
    `--R. reticulata Fan, Rigby & Zhang 1991 RLS04
  Cassiniastraea Volz 1896 RS01
  Parkeria sphaerica S02
  ‘Turris’ neglectus Lesson 1837 F27
  Phialidium B26
    |--P. hemisphericum D56
    `--P. languidum B26
  Staurophora mertensii [incl. S. falklandica Browne 1902] B26
  Cambrohydra EL11
  Keramosphaerina Stache 1913 [=Bradya Stache 1889 nec Boeck 1872 nec Carter 1877] LT64
    `--*K. tergestina (Stache 1889) [=*Bradya tergestina] LT64
  Rhaptapagis cantacuzenei CS-P86
  Ceratella Gray 1868 B86
    `--C. fusca Gray 1868 B86
  Dehitella atrorubens B86
  Craspedonites Haeckel 1865 [=Craspedites (l. c.) non Pavlow 1892] WCH96
  Haliscera BP00
    |--H. bigelowi Kramp 1947 BP00
    `--H. racovitzae (Maas 1906) BP00
  Arctapodema australis (Vanhöffen 1902) BP00
  Sminthea eurygaster Gegenbauer 1857 BP00
  Amphinema rubra (Kramp 1957) BP00
  Ventromma halecioides PP64
  Monotheca posidoniae PP64
  Polyplumaria secundaria PP64

Radiotrabeculopora Fan, Rigby & Zhang 1991 [incl. Flabellisclera Wu 1991, Fungispongia Wu 1991, Gigantosclera Wu 1991, Tubulispongia Wu 1991; Disjectoporidae] RLS04

*Type species of generic name indicated

REFERENCES

[BK77] Barel, C. D. N., & P. G. N. Kramers. 1977. A survey of the echinoderm associates of the north-east Atlantic area. Zoologische Verhandelingen 156: 1–159.

[BU02] Bates, D. E. B., & A. Urbanek. 2002. The ultrastructure, development, and systematic position of the graptolite genus Mastigograptus. Acta Palaeontologica Polonica 47 (3): 445–458.

[B26] Bigelow, H. B. 1926. Plankton of the offshore waters of the Gulf of Maine. Bulletin of the Bureau of Fisheries 40 (2): 1–509.

[BP00] Bouillon, J., F. Pagès, J.-M. Gili, A. Palanques, P. Puig & S. Heussner. 2000. Deep-water hydromedusae from the Lacaze-Duthiers submarine canyon (Banyuls, northwestern Mediterranean) and description of two new genera, Guillea and Parateclaia. Scientia Marina 64 (Suppl. 1): 87–95.

[B86] Brazier, J. 1886. Notes on the distribution of Ceratella fusca, Gray. Proceedings of the Linnean Society of New South Wales, series 2, 1 (2): 575–576.

[B70] Bulman, O. M. B. 1970. Graptolithina with sections on Enteropneusta and Pterobranchia. In: Teichert, T. (ed.) Treatise on Invertebrate Paleontology pt V 2^nd ed. pp. V1–V149. The Geological Society of America, Inc.: Boulder (Colorado), and the University of Kansas: Lawrence (Kansas).

[B79] Buss, L. W. 1979. Habitat selection, directional growth and spatial refuges: why colonial animals have more hiding places. In: Larwood, G., & B. R. Rosen (eds) Biology and Systematics of Colonial Organisms pp. 459–497. Academic Press: London.

[CS-P86] Clausen, C., & L. v. Salvini-Plawen. 1986. Cnidaria. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) pp. 33–42. E. J. Brill/Dr W. Backhuys: Leiden.

[C45] Colenso, W. 1845. Memoranda of an excursion, made in the Northern Island of New Zealand, in the summer of 1841–2; intended as a contribution towards the natural productions of the New Zealand groupe: with particular reference to their botany (concluded). Tasmanian Journal of Natural Science 2: 241–308.

[DB07] Daly, M., M. R. Brugler, P. Cartwright, A. G. Collins, M. N. Dawson, D. G. Fautin, S. C. France, C. S. McFadden, D. M. Opresko, E. Rodriguez, S. L. Romano & J. L. Stake. 2007. The phylum Cnidaria: a review of phylogenetic patterns and diversity 300 years after Linnaeus. Zootaxa 1668: 127–182.

[D56] Dawes, B. 1956. The Trematoda with special reference to British and other European forms. University Press: Cambridge.

[DPH05] Dunn, C. W., P. R. Pugh & S. H. D. Haddock. 2005. Molecular phylogenetics of the Siphonophora (Cnidaria), with implications for the evolution of functional specialization. Systematic Biology 54 (6): 916–935.

[EL11] Erwin, D. H., M. Laflamme, S. M. Tweedt, E. A. Sperling, D. Pisani & K. J. Peterson. 2011. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science 334: 1091–1097.

[F27] Finlay, H. J. 1927. New specific names for austral Mollusca. Transactions and Proceedings of the New Zealand Institute 57: 488–533.

[G79] Glaessner, M. F. 1979. Precambrian. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A79–A118. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[H04] Haeckel, E. 1899–1904. Kunstformen der Natur. Bibliographisches Institut: Leipzig und Wien.

[H15] Harmer, S. F. 1915. The Polyzoa of the Siboga Expedition—Part I. Entoprocta, Ctenostomata and Cyclostomata. E. J. Brill: Leyden.

[IF02] Ivantsov, A. Yu., & M. A. Fedonkin. 2002. Conulariid-like fossil from the Vendian of Russia: A metazoan clade across the Proterozoic/Palaeozoic boundary. Palaeontology 45 (6): 1219–1229.

[KC60] Knight, J. B., L. R. Cox, A. M. Keen, R. L. Batten, E. L. Yochelson & R. Robertson. 1960. Gastropoda: systematic descriptions. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt I. Mollusca 1: Mollusca—General Features, Scaphopoda, Amphineura, Monoplacophora, Gastropoda—General Features, Archaeogastropoda and some (mainly Paleozoic) Caenogastropoda and Opisthobranchia pp. I169–I331. Geological Society of America, and University of Kansas Press.

[LT64] Loeblich, A. R., Jr & H. Tappan. 1964. Sarcodina: chiefly “thecamoebians” and Foraminiferida. In Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt C. Protista 2 vol. 2. The Geological Society of America and The University of Kansas Press.

[PP64] Peres, J. M., & J. Picard. 1964. Nouveau manuel de bionomie benthique de la mer Mediterranee. Recueil des Travaux de la Station Marine d'Endoume, Bulletin 31 (27): 5–137.

[P79] Petersen, K. W. 1979. Development of coloniality in Hydrozoa. In: Larwood, G., & B. R. Rosen (eds) Biology and Systematics of Colonial Organisms pp. 105–139. Academic Press: London.

[RLS04] Rigby, J. K., G. A. Linder & C. H. Stevens. 2004. A new occurrence of the “hydrozoan” Radiotrabeculopora reticulata Fan, Rigby, and Zhang, 1991 in the Permian of California. Journal of Paleontology 78 (2): 410–413.

[RS01] Roniewicz, E., & J. Stolarski. 2001. Triassic roots of the amphiastraeid scleractinian corals. Journal of Paleontology 75 (1): 34–45.

[RL03] Ryland, J. S., & J. E. Lancaster. 2003. Revision of methods for separating species of Protopalythoa (Hexacorallia: Zoanthidea) in the tropical West Pacific. Invertebrate Systematics 17: 407–428.

[SG-M98] Schäfer, P., & J. A. Grant-Mackie. 1998. Revised systematics and palaeobiogeography of some Late Triassic colonial invertebrates from the Pacific region. Alcheringa 22 (2): 87–122.

[S02] Scott, R. W. 2002. Albian caprinid rudists from Texas re-evaluated. Journal of Paleontology 76 (3): 408–423.

[VV77] Vervoort, W., & P. Vasseur. 1977. Hydroids from French Polynesia with notes on distribution and ecology. Zoologische Verhandelingen 159: 1–98.

[WCH96] Wright, C. W., J. H. Calloman & M. K. Howarth. 1996. Treatise on Invertebrate Paleontology pt L. Mollusca 4, revised vol. 4. Cretaceous Ammonoidea. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

Last updated: 29 November 2017.