Polyp Predicament: 2b-RAD reveals hidden dissimilarity in genus Zoanthus (Anthozoa: Hexacorallia)

Abstract

Zoanthids (order Zoantharia, Gray 1832) are found in shallow reef systems throughout tropical oceans. These corals are also common in-home aquariums where their vibrant colors make them highly sought after. Over years of study these organisms have been grouped in a myriad of ways due to the complexity of identifying them morphologically. More recently, molecular techniques have been employed in zoanthid identification. Over the past twenty years researchers have produced many gene trees and used phylogenies to resolve zoanthid species relationships, but often produced contradictory results. In this study, we investigated 15 zoanthids that are popular within the aquarium trade, and one collected in the Florida Keys. Our aim was to identify potential linkages between morphology and genetics and determine how to best resolve species delimitations in the genus Zoanthus. 2b-RAD improved the ability to resolve species boundaries within the genus Zoanthus and a lack of consensus revealed a disconnect between molecular markers and morphology.