A new genus of soft coral (Octocorallia, Malacalcyonacea, Cladiellidae) and three new species from Indo-Pacific coral reefs.

Molecular systematic studies of the anthozoan class Octocorallia have revealed widespread incongruence between phylogenetic relationships and taxonomic classification at all levels of the Linnean hierarchy. Among the soft coral taxa in order Malacalcyonacea, the family Alcyoniidae and its type genus Alcyonium have both been recognised to be highly polyphyletic. A recent family-level revision of Octocorallia established a number of new families for genera formerly considered to belong to Alcyoniidae, but revision of Alcyonium is not yet complete. Previous molecular studies have supported the placement of Alcyoniumverseveldti (Benayahu, 1982) in family Cladiellidae rather than Alcyoniidae, phylogenetically distinct from the other three genera in that family. Here we describe a new genus, Ofwegenumgen. nov. to accommodate O.verseveldticomb. nov. and three new species of that genus, O.coronalucissp. nov., O.kloogisp. nov., and O.collisp. nov., bringing the total number of species in this genus to four. Ofwegenumgen. nov. is a rarely encountered genus so far known from only a few locations spanning the Indian and western Pacific Oceans. We present the morphological characters of each species and use molecular data from both DNA barcoding and target-enrichment of conserved elements to explore species boundaries and phylogenetic relationships within the genus.

Non-native coral species dominate the fouling community on a semi-submersible platform in the southern Caribbean.

A coral community was examined on a semi-submersible platform that was moored at the leeward side of Curaçao, in the southern Caribbean, from August 2016 until August 2017. This community included several non-native or cryptogenic species. Among them were two scleractinian corals (Tubastraea coccinea and T. tagusensis) and two octocorals (Chromonephthea sp. and an unidentified Nephtheidae sp.). This is the first reported presence of T. tagusensis in the southern Caribbean, and the genus Chromonephthea in the Caribbean region. An ascidian, Perophora cf. regina, is also reported from the southern Caribbean for the first time, as well as a coral-associated vermetid gastropod, Petaloconchus sp., first recorded in the Caribbean in 2014. Lack of biofouling management could potentially harm indigenous marine fauna through the introduction of non-native species. Therefore monitoring communities associated with semi-submersible platforms is essential to track the presence and dispersal of non-native, potentially invasive species.

In the aftermath of Hurricane Irma: Colonization of a 4-year-old shipwreck by native and non-native corals, including a new cryptogenic species for the Caribbean.

Little is known about early coral settlement on shipwrecks with regard to their species and size compositions. Hurricanes in the Caribbean have a long history of sinking ships but a link with new coral settlement is understudied. In 2017, Hurricane Irma caused the sinking of over 300 vessels in the coastal waters of Saint Martin, eastern Caribbean. In 2021, coral settlement was studied on one of them, which included two native, one non-native, and two cryptogenic species. The corals were smaller than 8 cm in diameter. The invasive Tubastraea coccinea was the most abundant scleractinian and was predominantly represented by juveniles. A cryptogenic species, Stragulum bicolor, new for the Caribbean, was the most common octocoral. Because they can be harmful to the environment, shipwrecks should be monitored frequently for the occurrence of non-native species, especially when they are only a few years old.

Trait-based approaches reveal that deep reef ecosystems in the Western Indian Ocean are functionally distinct.

Tropical deep reefs (>30 m) are biologically and ecologically unique ecosystems with a higher geographic reach to shallow (<30 m) reefs. Yet they are poorly understood and rarely considered in conservation practices. Here, we characterise benthic and fish communities across a depth gradient (10-350 m) in remote coral atolls in Seychelles, Western Indian Ocean. Using taxonomic and trait-based approaches we present the taxonomic and functional composition of shallow and deep reef communities, with distinct communities and traits dominating different depths. Depth-related changes in community metrics (taxa richness, abundance and biomass) and functional diversity metrics (richness, dispersion, and evenness) indicate complex relationships across different biological components (fish, benthos) that differ between shallow and deep reefs. These in turn translate into different patterns of reef resilience against disturbance or species invasions with depth. Notably, deep reefs host on average fewer and less abundant taxa but with higher functional contribution and originality scores, some of which are of conservation concern. Overall, the results highlight the unique nature of deep reefs that requires their explicit consideration in conservation and management activities.

On some encrusting Xeniidae (Octocorallia): Re-examination of the type material of Sansibia flava (May, 1898) and a description of new taxa.

The type of the xeniid soft coral Sansibia flava (May, 1898) is re-described for the first time and its morphological diagnosis is presented. A subsequent integrated analysis of molecular and morphological characters of related Xeniidae, including species indigenous to the Indo-Pacific Ocean and invasive in the Atlantic (Brazil), led to the description of a new Sansibia species, as well as two new genera comprising an additional three new species. All of these taxa are encrusting, with polyps arising directly from a spreading basal membrane. Molecular phylogenetic analyses show that these genera are not sister taxa, thus further emphasizing the remarkable phylogenetic diversity of xeniids with such a growth form. The sclerites of all species are uniformly ellipsoid platelets, abundant throughout the colony. The species exhibit restricted, non-overlapping geographic ranges, with distinct genotypes (molecular operational taxonomic units) found in different marine realms. The results emphasize the importance of re-examination of original old type material while applying molecular phylogenetic analyses in order to delineate species boundaries and to recognize biodiversity patterns.

Reef benthos of Seychelles - A field guide.

BACKGROUND: During the 2019 First Descent: Seychelles Expedition, shallow and deep reef ecosystems of the Seychelles Outer Islands were studied by deploying a variety of underwater technologies to survey their benthic flora and fauna. Submersibles, remotely operated vehicles (ROVs) and SCUBA diving teams used stereo-video camera systems to record benthic communities during transect surveys conducted at 10 m, 30 m, 60 m, 120 m, 250 m and 350 m depths. In total, ~ 45 h of video footage was collected during benthic transect surveys, which was subsequently processed using annotation software in order to assess reef biodiversity and community composition. Here, we present a photographic guide for the visual identification of the marine macrophytes, corals, sponges and other common invertebrates that inhabit Seychelles' reefs. It is hoped that the resulting guide will aid marine biologists, conservationists, managers, divers and naturalists with the coarse identification of organisms as seen in underwater footage or live in the field. NEW INFORMATION: A total of 184 morphotypes (= morphologically similar individuals) were identified belonging to Octocorallia (47), Porifera (35), Scleractinia (32), Asteroidea (19), Echinoidea (10), Actiniaria (9), Chlorophyta (8), Antipatharia (6), Hydrozoa (6), Holothuroidea (5), Mollusca (2), Rhodophyta (2), Tracheophyta (2), Annelida (1), Crinoidea (1), Ctenophora (1), Ochrophyta (1) and Zoantharia (1). Out of these, we identified one to phylum level, eight to class, 14 to order, 27 to family, 110 to genus and 24 to species. This represents the first attempt to catalogue the benthic diversity from shallow reefs and up to 350 m depth in Seychelles.

A new species of Melithaea (Anthozoa, Octocorallia, Melithaeidae) from the Oman Sea, off Oman.

A new species, Melithaea davidisp. n., is described from the eastern coast of Oman, Oman Sea, in the northwestern Indian Ocean, where it differs from its congeners in lacking capstans and having predominantly spindles in the coenenchyme. A molecular phylogenetic analysis of mtMutS and 28S rDNA genes suggests that it is genetically distinct from similar species in the Red Sea. Furthermore, a species previously reported as Acabaria sp. from the Arabian Sea is now identified as Melithaea mabahissi (Hickson, 1940).

A revision of Trimuricea Gordon, 1926 (Cnidaria: Octocorallia: Plexauridae) with the description of six new species.

The genus Trimuricea Gordon, 1926 is revised. An overview and identification key of all presently known Trimuricea species is given. The type material of Trimuricea africana Gordon, 1926, T. reticulata (Thomson & Simpson, 1909), T. merguiensis Gordon, 1926, T. inermis (Nutting, 1910), T. magna (Nutting, 1910) and T. caledonica Grasshoff, 1999, is re-examined. Trimuricea andamanensis (Thomson & Simpson, 1909) is assigned to Echinogorgia Kölliker, 1865, Trimuricea aff. reticulata (Samimi-Namin & van Ofwegen 2009a) is synonymised with T. persica n. sp.; and T. magna (Nutting, 1910) with T. inermis (Nutting, 1910). Furthermore, six new species are described and depicted, T. bicolor, T. flava, T. omanensis, T. persica, T. tuberculosa, and T. spinosa, increasing the number of known Trimuricea species to eleven.

Overview of the genus Briareum (Cnidaria, Octocorallia, Briareidae) in the Indo-Pacific, with the description of a new species.

The status of Indo-Pacific Briareum species (Cnidaria, Octocorallia, Briareidae) is reviewed by presenting their sclerite features and habitus descriptions. Following the re-examination of type material, museum specimens and newly collected specimens, a species identification key is provided. The species distributions are discussed and updated distribution ranges are depicted. Moreover, a new taxon, Briareum cylindrum sp. n. is described and depicted, whereas Briareum excavatum (Nutting, 1911) is synonymised with Briareum stechei (Kükenthal, 1908). Briareum hamrum (Gohar, 1948) is recorded from the Persian Gulf and Oman Sea for the first time. Consequently, in total four Briareum species are recognized in the Indo-Pacific; Briareum hamrum from the western Indian Ocean, and Briareum cylindrum sp. n., Briareum stechei, and Briareum violaceum from the central and eastern Indo-Pacific region.

Critical research needs for identifying future changes in Gulf coral reef ecosystems.

Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter 'Gulf') coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms of scientific importance (i.e., filled a knowledge gap and was a research priority) and efficiency in resource use (i.e., was highly feasible and ecologically broad). Ten research questions, in six major research areas, were highly important for both understanding Gulf coral reef ecosystems and also an efficient use of limited research resources. These questions mirrored global evaluations of the importance of understanding and evaluating biodiversity, determining the potential impacts of climate change, the role of anthropogenic impacts in structuring coral reef communities, and economically evaluating coral reef communities. These questions provide guidance for future research on coral reef ecosystems within the Gulf, and enhance the potential for assessment and management of future changes in this globally significant region.