Marine Biodiversity最新文献

Astrangia Milne Edwards & Haime, 1848 is a small, poorly known genus of Scleractinia, composed of 15 extant species with circumtropical to temperate distributions. Only two species of this genus have been distinguished in shallow-water environments along the Brazilian coast: A. solitaria (Le Sueur, 1817) and A. rathbuni Vaughan, 1906. Here, we describe a new, blue Astrangia species from the northeastern Brazilian coast. Scanning electron microscopy images of the corallites supported the taxonomic analysis and the description of the new species. Early confused with Astrangia woodsi Wells, 1955, an incrusting coral with blue-gray polyps, the new species is a zooxanthellate, solitary brooding coral and can easily be recognized in biofouling communities because of its solitary shape instead of the colonial development of A. woodsi. The new species was observed on artificial substrates, co-occurring with non-native invertebrates, such as the bryozoan Triphyllozoon arcuatum (MacGillivray, 1889), and “sun corals” of the genus Tubastraea Lesson 1830). This is the second Astrangia species reported from Brazil, updating the inventory for the entire South Atlantic to five recorded species. Its reproduction mode as a brooder was determined through histological examination, showing embryos in the mesenteries. A key to all extant Astrangia species is provided together with an infographic about its distribution and environmental preferences across the globe.

There is a lack of standardised imaging methods for marine zooplankton due to the difficulty of manipulating small and often fragile specimens. Yet, standardised 2D photographs and 3D scans provide important morphological information to accompany DNA-barcoded specimens for reference databases such as the Barcode of Life Data System (BOLD). Shelled pteropods are considered as bio-indicators to study impacts of ocean acidification, and thus, it is especially important to obtain high-quality records of their fragile aragonitic shells. We used alcohol-based hand sanitiser gel as a medium for photographing pteropods of the genus Limacina prior to micro-CT scanning and destructive DNA analysis. The high viscosity and transparency of the hand sanitiser enabled easy handling of the specimens so that they could be positioned in a standardised orientation and photographed with a stacking microscope. The high-quality photographs provide a record of morphology and allow for subsequent geometric morphometric analyses. This method did not impact the downstream micro-CT and molecular analyses of the same specimens and resulted in publicly available 2D and 3D digital vouchers as well as ten reference DNA barcodes (partial Cytochrome Oxidase I gene sequences). While alcohol-based hand sanitiser entered our daily lives due to a distressing pandemic, we could make use of it as a cheap and easily available resource to make high quality voucher photographs of shelled pteropods. Digital vouchers serve as a record of their morphology for further taxonomic analyses and facilitate studies assessing shell growth and impacts of ocean acidification.

Environmental DNA (eDNA) metabarcoding leverages genetic material present in the habitat for detection of species and has great potential for rapid biodiversity assessment. Comprehensive eDNA characterization of marine metazoan biodiversity requires broad amplification of genetic markers or complementary loci to detect a wide diversity of taxa. In this study, we tested the effectiveness of the universal cytochrome c oxidase subunit I (COI) and marine vertebrate 16S ribosomal RNA markers to recover coastal marine taxa from eDNA samples collected along the urban coast of Singapore. We recovered 260 molecular operational taxonomic units (MOTUs) from a total of 12 L of water (triplicates of 1 L at each of four sites) with no overlap of MOTUs observed between the two assays despite the expectation that the COI primer set could potentially amplify a broad range of metazoans. Notably, our COI assay identified mainly invertebrates, while the 16S assay primarily recovered vertebrates. For the relatively new 16S barcoding marker, we applied two species delimitation programs on a curated, comprehensive vertebrate dataset to determine the distance threshold between intra- and interspecific comparisons (2%). Community analyses revealed that metazoan communities were distinct between sites for both assays. In addition, DNA metabarcoding was shown to be helpful for the monitoring of non-indigenous and threatened marine species, such as Mytella strigata and Aetobatus ocellatus, respectively. Our findings highlight the potential of a complementary multi-marker approach for biomonitoring invertebrates and vertebrates comprehensively across distinct habitats.

Pelagic polychaetes were collected in the Bransfield Strait, the Weddell Sea, and near the South Orkney Islands area in the austral summer of 2022 during the 87^th cruise of the R/V Akademik Mstislav Keldysh. The collected material was studied using morphological, taxonomic, and molecular methods; 18S and D1 regions of 28S genes were used as molecular markers. In total, 17 species were recognized in the studied material, including Alciopini (2), Lopadorrhynchidae (4), Iospilidae (1), Typhloscolecidae (6), and Tomopteridae (4). We clarified relationships between Vanadis antarctica McIntosh, 1885, and V. longissima (Levinsen, 1885). One new typhloscolecid Typhloscolex keldyshi sp. nov. and two new species of Lopadorrhynchidae Pelagobia albertych sp. nov. and Pelagobia torquata sp. nov. have been described. Also, we propose to restore Pelagobia viguieri Gravier, 1911, based on molecular data.

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.