Zoanthids of the Cape Verde Islands and their symbionts: previously unexamined diversity in the Northeastern Atlantic

The marine invertebrate fauna of the Cape Verde Islands contains many endemic species due to their isolated location in the eastern Atlantic, yet research has not been conducted on most taxa here. One such group are the zoanthids or mat anemones, an order of benthic cnidarians (Hexacorallia: Zoantharia) common in many marine environments. In this study, the diversity of zoanthids in the Cape Verde Islands is specifically examined for the first time. Field images and sampling are combined with molecular phylogenetic analyses utilizing two mitochondrial DNA markers (cytochrome oxidase subunit I and 16S ribosomal DNA) to determine the number of species present. Specimens from eight species (Palythoa caribaeorum, Palythoa sp. 265, Zoanthus aff. pulchellus, Isaurus tuberculatus, Parazoanthus sp. 269, Parazoanthus sp. 1401, Antipathozoanthus macaronesicus, Terrazoanthus sp. 276) were identified, including two to four species that are likely new to science. Additional examinations of Symbiodinium endosymbionts in zooxanthellate species showed that clades A, B, and C were present; this is the first report of clade B associating with a zoanthid species. An appendix describing the eight zoanthid species found in the Cape Verde Islands is included to provide a base for future zoanthid research in this region.