Order Anthoathecata

Order Anthoathecata Cornelius, 1992

synonyms	Athecata Hincks, 1868; Gymnoblastea Allman, 1871; Anthomedusae Haeckel, 1879.
diagnosis	Hydrozoans that always have a polyp stage. Hydranths either solitary or colonial, body not covered by firm perisarc. Medusae not colonial, without statocysts, with gonads on manubrium, with radial canals, with tentacles arising from bell-margin. Cnidome normally includes desmonemes (not Eudendriidae and Laingiidae).
higher classification	Cnidaria, Medusozoa, Hydrozoa, Leptolinae
species	about 1200

how to recognize?

gonads on manubrium

high medusa bell

no statocysts

polyp body is not in a rigid hydrotheca

beware: some groups have a filmy covering of the hydranth body, a pseudohydrotheca, often covered by dirt

specific terms

Important terms used in athecate hydroids and their medusae

Tentacle types of polyps of Anthomedusae, nematocyst tissue stippled

a) filiform

b) moniliform

c) acnid (no nematocysts)

d) capitate

e) cateniform

f) branched capitate

g) semimoniliform

h) moniliform

i) semifiliform

j) pseudofiliform

Some specialised structures found in Anthomedusae (examples are Halitiara inflexa and Pandea conica)

Some specialized structures found in Anthomedusae (examples are Lizzia blondina and Rathkea octopunctata, Bougainvilliidae). Note the presence of medusae buds on the manubrium, leading to a vegetative propagation of medusae individuals.

Oral tentacles originate above the level of the mouth, oral arms originate at the level of the mouth and can be seen as elongated mouth lips.

similar forms

Naked scyphopolyps, limnopolyps and certain polyp phases of Leptomedusae that either shed their hydrotheca (e. g. Eirenidae, Aequoridae), or have a very short, but stiff Hydrotheca (Haleciidae) can easily be confounded with polyps of the Anthomedusae

Sycophopolyps have four septal funnels and four sepatae, tare usually solitary, and hey strobilate medusae.

Limnopolyps are not easily separable in the absence of information on the gonophore, but the few types of polyps found in the Limnomedusae facilitate an identification.


a scyphopolyp	Aequorea, a genus of the Leptomedusae, has a very inconspicuous, soft hydrotheca	Halecium, a genus of the Leptomedusae, has a very shallow hydrotheca

Suborders

Capitata

Stenoteles always present. Polyp tentacles capitate, moniliform, or filiform; if filiform then often in two well separated whorls. Mouth of medusa mostly simple, circular, sometimes cruciform, without crenulated lips, oral arm, oral tentacles.

Filifera

Hydroid colonial, always with filiform tentacles except for the dactylozooids of the Ptilocodiidae. Medusa gonads on the walls of the manubrium, sometimes also on basal extensions of the manubrium, mouth with tetra-radial symmetry, either trough cruciform lips or manubrial tentacles. The cnidome never includes stenoteles.

References

Kramp, P. L. 1959a. The Hydromedusae of the Atlantic Ocean and adjacent waters. Dana Report 46: 1-283.

Millard, N.A.H. 1975. Monograph on the Hydroida of southern Africa. Annals of the South African Museum 68: 1-513.

Russell, F. S. 1953.The medusae of the British Isles. Cambridge University Press, London, pp. 530, 35 pls.

Schuchert, P. 1996.The marine fauna of New Zealand: athecate hydroids and their medusae (Cnidaria: Hydrozoa). New Zealand Oceanographic Institute Memoir 106: 1-159.