Craspedacusta Lankester, 1880

Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, Zootaxa 2590 (1), pp. 1-91 : 73-74

Genus Craspedacusta Lankester, 1880

Craspedacusta Lankester, 1880: 147 .

Type species. Craspedacusta sowerbii Lankester, 1880 , by monotypy.

Diagnosis. Olindiid polyps solitary or primitively colonial. Hydranths atentaculate, athecate, club-shaped to cylindrical; distal end a knob-shaped capitulum, bearing an apical mouth surrounded by nematocysts; hydranth base with attachment region surrounded by thin perisarc; asexual reproduction by frustulation, cyst formation, or fission.

Gonophores medusae, arising from gastric column of hydranth. Medusae hemispherical to dome-shaped, with marginal nematocyst ring; radial canals four; centripetal canals absent; manubrium quadrate, moderately short, gastric peduncle absent; tentacles evenly spaced, of one type, lacking adhesive disks; statocysts in vesicles on velum; gonads sac-shaped, on radial canals.

Remarks. Bouillon et al. (2006) listed eight nominal species in Craspedacusta Lankester, 1880 , but speculated that they might all be conspecific with C. sowerbii Lankester, 1880 . Earlier, He et al. (2000) had recognized six species, while Dumont (1994) reported that four species were considered valid by most workers. Jankowski (2001) and Jankowski et al. (2008) believed there were as many as four species endemic to the Yangtze River Basin in China, the likely origin of the genus. Several species of the genus appear valid from molecular data ( Collins et al. 2008; Zhang et al. 2009). The species taxonomy of this enigmatic fresh water genus remains unsettled.