New ecological and phylogenetic insights in the boring barnacle Berndtia Utinomi, 1950 (Acrothoracica: Lithoglyptidae) reveal higher diversity, new hosts, and range extension to the Western Indian Ocean

The acrothoracican genus Berndtia Utinomi, 1950 includes small barnacles known to bore into the calcareous skeleton of living scleractinian corals of the genera Psammocora Dana, 1846 and Leptastrea Milne Edwards & Haime, 1849. The six known species of Berndtia are restricted to the tropical Western Pacific. We provide the first record of Berndtia from the hydrocoral Millepora exaesa Forsskål, 1775 from the central Red Sea, Saudi Arabia, and the scleractinian coral Coscinaraea cf. monile (Forsskål, 1775) from the Arabian Sea, Oman. These findings extend the known range and host use of the genus and raise questions about Berndtia’s host specificity. A molecular analysis of Saudi Arabian and Omani specimens suggests that they belong to two new lineages that may represent new species of Berndtia, each associated with multiple hosts. Further sampling around the Arabian Peninsula and the Western Indian Ocean and exploration of additional potential hosts would provide new insights into the species diversity of the genus.