Abstract
Okinawa zoanthids have only recently begun to be investigated intensively. Recent research has confirmed the presence of several previously unknown species in the shallow coral reef waters surrounding Okinawa. Here, to aid zoanthid researchers in field identification, a dichotomous key of brachycnemic zoanthids (families Sphenopidae, Zoanthidae, Neozoanthidae) is provided, with characters almost exclusively based on ecology and morphology, although all taxa listed have also been examined using molecular phylogeny. With this key, five species of Palythoa, four species of Zoanthus, and one taxon each of Sphenopus, Isaurus, Neozoanthus, as well as an undescribed zoanthid genus are identifiable. Although not common, other as of yet undescribed brachycnemic zoanthids are likely to exist in Okinawa waters, and it is hoped this key will help spur further research into their biodiversity.
