Abstract
Atlantia is described as a new genus pertaining to the family Dendrophylliidae (Anthozoa, Scleractinia) based on specimens from Cape Verde, eastern Atlantic. This taxon was first recognized as Enallopsammia micranthus and later described as a new species, Tubastraea caboverdiana, which then changed the status of the genus Tubastraea as native to the Atlantic Ocean. Here, based on morphological and molecular analyses, we compare fresh material of T. caboverdiana to other dendrophylliid genera and describe it as a new genus named Atlantia in order to better accommodate this species. Evolutionary reconstruction based on two mitochondrial and one nuclear marker for 67 dendrophylliids and one poritid species recovered A. caboverdiana as an isolated clade not related to Tubastraea and more closely related to Dendrophyllia cornigera and Leptopsammia pruvoti. Atlantia differs from Tubastraea by having a phaceloid to dendroid growth form with new corallites budding at an acute angle from the theca of a parent corallite. The genus also has normally arranged septa (not Portualès Plan), poorly developed columella, and a shallow-water distribution all supporting the classification as a new genus. Our results corroborate the monophyly of the genus Tubastraea and reiterate the Atlantic non-indigenous status for the genus. In the light of the results presented herein, we recommend an extensive review of shallow-water dendrophylliids from the Eastern Atlantic.