Discovery of Neonrosellavitiata (Darwin) and Newmanellaspinosus Chan & Cheang (Balanomorpha, Tetraclitidae) from the Andaman Sea, eastern Indian Ocean

An annotated checklist and integrative biodiversity discovery of barnacles (Crustacea, Cirripedia) from the Moluccas, East Indonesia

To contribute to the taxonomic knowledge of barnacles in this understudied area, the first checklist of barnacles from the Moluccas is presented, including additional information on morphology, distribution, and substrate as well as molecular data. The species of barnacles from the Moluccas have been determined using morphological analysis and DNA sequences. During 19 field trips conducted between January 2016 and September 2017, 1,513 specimens of 24 species of intertidal and one species of deep-sea barnacles were collected from 51 localities from the islands. Morphological and molecular analysis of the collected material detected members of three families of stalked barnacles and four families of acorn barnacles. In addition to sampling in the field, we also surveyed the literature on barnacles from the Moluccas. In total, our checklist comprises 97 species from the Moluccas including 23 new records, two of them yet to be described species. Results suggest that the Moluccas have a much higher diversity of barnacles than previously known, for example, from the reports of Challenger and Siboga expeditions. For further work, routine application of molecular systematics could aid the detection of cryptic species, while increased sampling of more islands and a taxonomic revision of several groups would likely lead to an even higher number of species than currently known.

Morphological and molecular evidence support the intertidal barnacle Octomeris intermedia Nilsson-Cantell, 1921 (Thoracica, Chthamalidae) as a valid species in Indo-Pacific waters

Octomeris is a chthamalid intertidal barnacle with eight shell plates. There are currently two species of such barnacles: O. brunnea Darwin, 1854 (type locality in the Philippines), common in the Indo-Pacific region, and O. angulosa Sowerby, 1825, only recorded in South Africa. Octomeris intermedia Nilsson-Cantell, 1921, identified from the Mergui Archipelago in Myanmar, was considered to be conspecific with O. brunnea by Hiro (1939) based on samples collected in Taiwan. The morphological differences in shell and opercular plates between O. brunnea and O. intermedia are believed to be intra-specific variations due to different degrees of shell erosion. In the present study, the genetic and morphological differentiations of Octomeris in the Indo-Pacific region were examined. This study found two molecular clades (with inter-specific differences) based on the divergence in the COI genes, and the species also have distinct geographical distributions. The Octomeris brunnea clade covers samples collected from the Philippines and Taiwan waters and the other clade, which we argue is O. intermedia, is distributed in Phuket and Krabi, Thailand and Langkawi, Malaysia. Phuket and Krabi are located approximately 300 km south of the Mergui Archipelago, the type locality of O. intermedia. The morphology of samples collected from Thailand fits the type description of O. intermedia in Nilsson-Cantell (1921). Our study concludes that O. intermedia is a valid species based on morphological and molecular evidence.