Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590 Author Calder, Dale R. text Zootaxa 2010 2010-08-31 2590 1 1 91 https://biotaxa.org/Zootaxa/article/view/zootaxa.2590.1.1 journal article 10.11646/zootaxa.2590.1.1 1175­5334 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.