The Red Sea is a biodiversity hotspot with a considerable percentage of endemic species for many marine animals. Little is known about the diversity and distribution of calcareous sponges (Porifera, Class Calcarea) in this marginal sea. Here we analysed calcareous sponges of the subclass Calcinea that were collected between 2009 and 2013 at 20 localities in the Red Sea, ranging from the Gulf of Aqaba in the north to the Farasan Islands in the south, to document the species of this region. For this, we applied an integrative approach: We defined OTUs based on the analyses of a recently suggested standard DNA marker, the LSU C-region. The analysis was complemented with a second marker, the internal transcribed spacer, for selected specimens. Ten OTUs were identified. Specimens of each OTU were morphologically examined with spicule preparations and histological sections. Accordingly, our ten OTUs represent ten species, which cover taxonomically a broad range of the subclass. By combining molecular and morphological data, we describe four new species from the Red Sea: Soleneiscus hamatus sp. nov., Ernstia arabica sp. nov., Clathrina rotundata sp. nov., and Clathrina rowi sp. nov.. One additional small specimen was closely related to “Clathrina” adusta, but due to the small size it could not be properly analysed morphologically. By providing the DNA sequences for the morphologically documented specimens in the Sponge Barcoding Database (www.spongebarcoding.org) we facilitate future DNA-assisted species identification of Red Sea Calcinea, even for small or incomplete samples, which would be insufficient for morphological identification. Application of DNA barcode methods in the subclass will help to further investigate the distribution of Calcinea in the Red Sea and adjacent regions.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We would like to thank the Senckenberg Research Institute, in particular the sadly late Michael Türkay and Andreas Broesing, and the King Abdulaziz University, Jeddah, for enabling and supporting the collections, furthermore the team of the Red Sea Biodiversity Surveys in 2012 and 2013 for their help with sampling. For logistical assistance with the Thuwal region sampling, we thank the crew of the M/Y Dream Island (Dream Divers, Jeddah), Jessica Bouwmeester, and the King Abdullah University of Science and Technology (KAUST) Coastal and Marine Resources Core Lab. The scientific research cooperation between King Abdulaziz University (KAU), Faculty of Marine Sciences (FMS), Jeddah, Saudi Arabia, and the Senckenberg Research Institute (SRI), Frankfurt, Germany, in the framework of the Red Sea Biodiversity Project, during which some of the presented material was collected, was funded by KAU GRANT NO. “I/1/432-DSR”. The authors acknowledge, with thanks, KAU and SRI for technical and financial support. We are also grateful to the Egyptian Environmental Affairs Agency (EEAA), especially Mohammed Fouda, for permitting fieldwork in Egypt and to Alexander Keck and Christian Alter for their support during fieldwork in Egypt. We thank two anonymous reviewers for their constructive comments that helped us to improve the manuscript.