%0 Journal Article %T Species Diversity of Shallow Water Zoanthids (Cnidaria: Anthozoa: Hexacorallia) in Florida %A James Davis Reimer %A Colin Foord %A Yuka Irei %J Journal of Marine Biology %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/856079 %X Shallow water zooxanthellate zoanthids are a common component of the coral reef ecosystems of the Caribbean. Despite this, their species diversity remains poorly understood. In this study, collected Palythoa, Zoanthus, Isaurus, and Terrazoanthus specimens from the waters of Florida were phylogenetically examined to obtain a better understanding of zoanthid species diversity in the Caribbean. Surprisingly, the results from analyses utilizing three DNA markers (mitochondrial 16S ribosomal DNA, cytochrome oxidase subunit I, and the internal transcribed spacer of ribosomal DNA) showed the presence of at least eleven species, of which up to four appear undescribed. Additionally, the presence of the genus Terrazoanthus in the Caribbean was confirmed for the first time. Attempts to match phylogenetic species or clades with original literature were hampered by vague and short original descriptions, and it is clear that for Atlantic Palythoa and Zoanthus species an in-depth and multidisciplinary investigation is needed to reconcile recent phylogenetic results such as in this study with traditional taxonomy. Furthermore, most shallow water zoanthid species from Florida were observed to have close, sister-species relationships with previously investigated species in the Pacific Ocean. These results indicate that many brachycnemic zoanthid species likely had a Caribbean-Pacific distribution until the formation of the Isthmus of Panama. However, due to inadvertent redescriptions, overall species diversity in these two common genera is likely much lower than literature indicates. 1. Introduction The coral reef ecosystems of Florida are the only large area of shallow water coral reefs in the continental United States, and as such have been the subject of studies investigating their ecology [1], biodiversity, and recent history [2]. Despite this, the region has undergone rapid degradation in terms of live coral coverage due to coral bleaching [3] and disease [4], among other stressors, with corresponding large losses of live coral cover [5, 6]. One of the most common groups of organisms on the reefs of Florida and the Greater Caribbean is the zoanthids. In fact, some zoanthids (Anthozoa: Hexacorallia) are so common that a portion of the shallow intertidal zone has been called the ˇ°Zoanthus zoneˇ± [7]. Like many reef-building hard corals, most shallow tropical and subtropical zoanthids are in symbiosis with Symbiodinium (=zooxanthellae) species, endosymbiotic, photosynthetic dinoflagellates. Despite being an obvious and ubiquitous part of the Caribbean coral reef %U http://www.hindawi.com/journals/jmb/2012/856079/