IMIS

This updates the well-known and useful but largely outdated Hedgpeth 1969’s Folio on “Distribution of selected groups of marine invertebrates in waters south of 35°S latitude” in the Antarctic Map Folio Series (American Geographical Society). Antarctic benthic hydroids belong to the class Hydrozoa and are represented by members of the two hydrozoans subclasses, Hydroidolina and Trachylina. Peak diversity among hydrozoans in Antarctic benthic communities exists in the subclass Hydroidolina, represented by the orders Anthoathecata and Leptothecata, with the later being much better represented. Of 179 species considered, only two belong to Trachylina, in particular to the order Limnomedusae. The remaining 177 species are unequally distributed between Anthoathecata and Leptothecata.