Navigation:  Home  Animalia  Porifera  Cnidaria  Platyhelminthes  Nemertea  Gastrotricha  Rotifera  Bivalvia  Gastropoda  Annelida  Tardigrada  Arachnida  Branchiopoda  Ostracoda  Copepoda  Branchiura  Decapoda  Syncarida  Peracarida  Nematoda  Nematomorpha  Entoprocta  Bryozoa | Phylum Cnidaria (hydroids, jellyfish, anemones, corals, etc.) Fewer than 1% of cnidarian species occur in freshwater. The phylum is perhaps best known for marine jellyfish, corals, and sea anemone. In freshwater, the Cnidaria is represented by the Class Hydrozoa. However, only a few dozen species are known from inland habitats, and probably only about 10 occur in North America (Jankowski et al. 2008). The cnidarians represent a zoological advance in complexity over the Porifera in that they go through the developmental process of gastrulation and possess true tissues -- like other groups of metazoans. However, members of the Cnidaria only have two embryonic tissue layers. A unique characteristic of this phylum is alternation of generation between an asexual polyp stage and a sexual medusa stage (although one or the other may be suppressed in various taxa). The body plan is radially symmetrical with only a diffuse nerve net rather than a central nervous system. Go to images library. Bibliography - Pechenik, J.A. 2015. Biology of the Invertebrates, 7th edition. McGraw-Hill, NewYork.. 606 pp.
- Zhang, Z.-Q. 2011. Animal biodiversity: An introduction to higher-level classification and taxonomic richness. Zootaxa 3148: 7-12. [Available online]
- Slobodkin, L.B. & P.E. Bossert. 2010. Cnidaria. [in] J.H. Thorp & A.P. Covich (eds.). Ecology and Classification of North American Freshwater Invertebrates, 3rd edition: 125-142.
- Jankowski, T., A.G. Collins & R. Campbell. 2008. Global diversity of inland water cnidarians. Hydrobiologia 595: 35-40. [Available online]
- 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. [Available online]
- Brusca, R.C. & G.J. Brusca. 2003. Invertebrates, 2nd edition. Sinauer Associates, Inc., Sunderland, Massachusetts. 936 pp.
- Smith, D.G. 2001. Cnidaria (Hydroids, jellyfish). Pennak's Freshwater Invertebrates of the United States, 4th edition: 61-76.
- Jankowski, T. 2001. The freshwater medusae of the world — a taxonomic and systematic literature study with some remarks on other inland water jellyfish. Hydrobiologia 462: 91-113. [Available online]
- Dumont, H.J. 1994. The distribution and ecology of the fresh- and brackish-water medusae of the world. Hydrobiologia 272: 1-12. [Available online]
- Underhill, J.C., W.D. Schmid & D.E. Gilbertson. 1982. Taxonomic Keys to the Common Animals of the North Central States, exclusive of the parasitic worms, terrestrial insects, and birds, 4th edition. 205 pp.
- Batha, J.V. 1974. The distribution and ecology of the genus Hydra in the Milwaukee area of Lake Michigan. Ph.D. Dissertation, University of Wisconsin, Madison. 172 pp.
- Hyman, L.H. 1959. Coelenterata. [in] W.T. Edmondson (ed.). Ward & Whipple Fresh-Water Biology, 2nd edition: 313-322.
- Miller, D.E. 1936. A limnological study of Pelmatohydra with special reference to their quantitative seasonal distribution. Transactions of the American Microscopical Society 55(2): 123-193. [Available online]
- Welch, P.S. & H.A. Loomis. 1924. A limnological study of Hydra oligactis in Douglas Lake, Michigan. Transactions of the American Microscopical Society 43: 203-235. [Available online]
Student EssaysWeb PagesClassification of Freshwater TaxaOnly taxa found in North America are listed. Formatting indicates if they are known (to us) from North America, the midwestern states or Wisconsin. | Kingdom Animalia [details] Subkingdom Eumetazoa [details] Superphylum Radiata [details]
| | | Phylum Cnidaria (+ Coelenterata) (hydroids, jellyfish, anemones, corals, etc.) [details] |
.. | | Class Hydrozoa (hydroids) [details] |
... | | Subclass Hydroidolina (+ Hydroidomedusae) [details] |
.... | | Order Anthoathecata (+ Athecata, + Anthomedusae) [details] |
...... | | Family Hydridae (hydras) [details] |
....... | | Genus Hydra (+ Chlorohydra, + Pelmatohydra) [details] |
........ | | Species H. vulgaris (+ H. americana, + H. littoralis, + H. carnea), H. canadensis (+ H. pseudoligactis), H. oligactis (+ H. fusca), H. viridissima (+ H. viridis), H. cauliculata, ..., etc. |
...... | | Family Protohydridae [details] |
........ | | Species P. leuckarti [detail] |
...... | | Family Cordylophoridae [details] |
....... | | Genus Cordylophora [details] |
........ | | Species C. caspia (+ C. lacustris) [detail] |
.... | | Order Limnomedusae (+ Limnohydrina) [details] |
..... | | Family Olindiidae (+ Olindiadidae, + Olindiasidae) [details] |
...... | | Genus Craspedacusta (+ Limnocodium) [details] |
....... | | Species C. sowerbyi (+ C. sowerbii) (freshwater jellyfish) [detail] |
....... | | Species C. dactylopterum [detail] |
..... | | Species P. hydriforme [detail] |
| |