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Coral reefs are globally important ecosystems with high species diversity at both the macro and micro scales. In recent years, coral reefs have been heavily impacted by anthropogenic and natural stressors, including emerging diseases. Many of these diseases have been identified in reef-building corals, but other invertebrate taxa, such as soft corals, are increasingly at risk. This study focuses on a hybrid species complex within soft corals of the genus Sinularia, which dominate the shallow reefs of Guam, and the broader Indo-Pacific. These soft corals exhibit varying levels of disease susceptibility to Sinularia tissue loss disease (STLD), a chronic wasting disease. In the current study, we used next-generation amplicon sequencing of prokaryotic and eukaryotic communities within these soft corals to characterize their microbiomes, and develop a better understanding of the etiology of STLD. There were differences in specific ASVs across the microbiomes of healthy colonies of Sinularia maxima, Sinularia polydactyla and their hybrid (S. maxima x S. polydactyla). There was also a decline in the relative abundance of putatively beneficial symbionts (Symbiodinaceae and Endozoicomonas) in STLD-affected soft corals, but no consistent shifts towards a specific microbial community associated with STLD. The soft coral microbiomes also contained a high relative abundance of ASVs typically associated with terrestrial runoff. Our results suggest that the STLD phenotype may be due to a combination of factors, including infection by a yet unknown etiologic agent, shifts in putatively beneficial symbionts, and anthropogenic impacts on this shallow nearshore reef. [ABSTRACT FROM AUTHOR]

Soft corals (Cnidaria, Anthozoa, Octocorallia, Alcyonacea) produce internal sclerites of calcium carbonate previously shown to be composed of calcite, the most stable calcium carbonate polymorph. Here we apply multiple imaging and physical chemistry analyses to extracted and in-vivo sclerites of the abundant Red Sea soft coral, Ovabunda macrospiculata, to detail their mineralogy. We show that this species' sclerites are comprised predominantly of the less stable calcium carbonate polymorph vaterite (> 95%), with much smaller components of aragonite and calcite. Use of this mineral, which is typically considered to be metastable, by these soft corals has implications for how it is formed as well as how it will persist during the anticipated anthropogenic climate change in the coming decades. This first documentation of vaterite dominating the mineral composition of O. macrospiculata sclerites is likely just the beginning of establishing its presence in other soft corals. STATEMENT OF SIGNIFICANCE: Vaterite is typically considered to be a metastable polymorph of calcium carbonate. While calcium carbonate structures formed within the tissues of octocorals (phylum Cnidaria), have previously been reported to be composed of the more stable polymorphs aragonite and calcite, we observed that vaterite dominates the mineralogy of sclerites of Ovabunda macrospiculata from the Red Sea. Based on electron microscopy, Raman spectroscopy, and X-ray diffraction analysis, vaterite appears to be the dominant polymorph in sclerites both in the tissue and after extraction and preservation. Although this is the first documentation of vaterite in soft coral sclerites, it likely will be found in sclerites of other related taxa as well.

A comprehensive and thorough research study was undertaken in Digha and the neighbouring coastline of West Bengal to investigate the benthic communities in the area. The survey identified a total of 16 species, including 12 previously unrecorded soft coral species at the study sites. As a result of this investigation and considering the existing data, the total number of octocoral species in the region has been revised to 20 species. This research contribution, specifically documented the new record of 12 soft coral species, i.e., Dendronephthya ganjamensis Henderson, 1909; Carijoa riisei (Duchassaing & Michelotti, 1860; Muricella ramosa Thomson & Henderson, 1905; Acanthogorgia muricata Verrill, 1883; Menella sp.; Subergorgia suberosa (Pallas, 1766); Acanella robusta Thomson & Henderson, 1906; Junceella juncea (Pallas, 1766); Verrucella umbracula (Ellis & Solander, 1786); Lituaria hicksoni Thomson & Simpson, 1909; Pteroeides punctatum Thomson & Simpson, 1909; and Pennatula indica Thomson & Henderson, 1906 within the study area. [ABSTRACT FROM AUTHOR]

Soft corals, recognized as sessile marine invertebrates, rely mainly on chemical, rather than physical defense, by secreting intricate secondary metabolites with plausible pharmaceutical implication. Their ecological niche encompasses a diverse community of symbiotic microorganisms which potentially contribute to the biosynthesis of these bioactive metabolites. The emergence of new viruses and heightened viral resistance underscores the urgency to explore novel pharmacological reservoirs. Thus, marine organisms, notably soft corals and their symbionts, have drawn substantial attention. In this study, the chemical composition of four Mauritian soft corals: Sinularia polydactya, Cespitularia simplex, Lobophytum patulum, and Lobophytum crassum was investigated using LC–MS techniques. Concurrently, Illumina 16S metagenomic sequencing was used to identify the associated bacterial communities in the named soft corals. The presence of unique biologically important compounds and vast microbial communities found therein was further followed up to assess their antiviral effects against SARS-CoV-2 and HPV pseudovirus infection. Strikingly, among the studied soft corals, L. patulum displayed an expansive repertoire of unique metabolites alongside a heightened bacterial consort. Moreover, L. patulum extracts exerted some promising antiviral activity against SARS-CoV-2 and HPV pseudovirus infection, and our findings suggest that L. patulum may have the potential to serve as a therapeutic agent in the prevention of infectious diseases, thereby warranting further investigation. [ABSTRACT FROM AUTHOR]

Coral reef endogenous to the Red Sea ecosystem is one of the largest globally known living reefs that are remarkably distinctive to constant high temperature and salinity. Coral microbiota is one of the most important prespectives contributing to coral survival in such conditions. Four soft corals endogenous to the eastern Red Sea side at Al Rayyis White Head, KSA were collected and identified as Litophyton sp., Sinularia sp., Xenia sp. and Sarcophyton sp. Soft corals-associated microbiota were investigated using Illumina sequencing of bacterial 16S rRNA genes. Results revealed higher bacterial diversity. Assignment of bacterial reads at the phylum level revealed the predominance of Proteobacteria in all coral-associated microbiotas followed by Bacteroidetes and Firmicutes. At the family level, Litophyton sp. was dominated by Hahellaceae, Staphylococcaceae, Prevotellaceae, Moraxellaceae and Bacteroidaceae, while Xenia sp. was dominated by Hahellaceae and Anaplasmataceae. The microbiota of Sinularia sp. were dominated by Pseudomonadaceae and Enterobacteriaceae. Sarcophyton sp. microbiota mainly include members of Enterobacteriaceae only.

The coastal areas of the Red Sea within Saudi Arabia have a wide diversity of marine soft corals harboring many symbiotic bacteria that could present a potential source of many antibacterial metabolites. This study focused on the molecular characterization of antibiotic-producing bacteria associated with soft corals and investigated the influence of culture conditions on the production of their antibacterial extracts. Two soft coral samples were collected offshore from Yanbu City and identified as genus Sarcophyton. Screening for antibiotic-producing bacterial symbionts uncovered nine isolates with a wide inhibitory spectrum against gram-positive and negative bacteria. Phylogenetic analysis of the bioactive bacterial symbionts 16S rRNA gene sequences revealed the prevalence of gram-negative bacteria with seven isolates all belonging to class γ-proteobacteria. The remaining two isolates were represented within class firmicutes and actinobacteria. Eight isolates were grouped perfectly with their best matches. While the remaining ninth isolate was phylogenetically separated from all the species within the Photobacterium genus, suggesting that it could be a novel species. The optimum antibacterial compounds production was obtained in minimal media, at a temperature range of 25–28 °C, pH 7 and 100–150 rev/min agitation during 24–48 h of the incubation period, with moderate to high degree of thermal stability.

Aliena parva gen. et sp. nov. is described from Cocos Island, Costa Rica. The species was found at various islets and rocky outcrops north and northwest of the island, 20-30 m in depth. The genus is characterised by polyps, retracting into calyces, that form thin encrusting mats extending on dead or live substrates. Sclerites are mostly asymmetrical spindles. Anthocodial rods are arranged in points, not forming a collaret. Colonies and coenenchymal sclerites are red, and polyps are transparent. Using an integrative taxonomic approach, we found the new genus to morphologically and genetically differ from all other described taxa. The molecular phylogenetic analyses provide strong support for the placement of this new genus in the family Pterogorgiidae. Morphologically it is unlike any of the other members of this family, necessitating an amendment to the diagnosis of Pterogorgiidae. Like several other known taxa of octocorals with encrusting growth forms, Aliena gen. nov. appears to have evolved from a gorgonian ancestor by loss of an internal skeletal axis. It is the first member of Pterogorgiidae to be reported from the eastern Pacific, contributing further to the knowledge of marine biodiversity in the eastern tropical Pacific and to the octocoral biodiversity of Cocos Island in particular. [ABSTRACT FROM AUTHOR]

Octocorals are problematic in their systematics, and the extent of their biodiversity is poorly understood. Integrative taxonomy (the use of two or more lines of evidence for the delimitation and description of taxa) is seen as a promising way to produce more robust species hypotheses and achieve taxonomic progress in this group. However, many octocoral descriptions continue to rely on morphological evidence alone, and the prevalence of integrative methods is unclear. Here, a literature survey was conducted to gain an overview of historical description rates and to examine trends in the publication of integrative descriptions between the years 2000 and 2020. We find that recent description rates are among the highest in the history of octocoral taxonomy, and although increasing, integrative taxon descriptions remain in the minority overall. We also find that integrative taxonomy has been applied unevenly across octocoral groups and geographical regions. Description rates show no signs of slowing, and no ceiling of total species richness has yet come into view. Coupled with a continued overreliance on morphological variation, particularly at the species level, this suggests that we might be adding to the workload of taxa requiring future revision faster than such instances can be resolved. [ABSTRACT FROM AUTHOR]

Despite the current decline of scleractinian coral populations, octocorals are thriving on reefs in the Caribbean Sea and western North Atlantic Ocean. These cnidarians are holobiont entities, interacting with a diverse array of microorganisms. Few studies have investigated the spatial and temporal stability of the bacterial communities associated with octocoral species and information regarding the co-occurrence and potential interactions between specific members of these bacterial communities remain sparse. To address this knowledge gap, this study investigated the stability of the bacterial assemblages associated with two common Caribbean octocoral species, Eunicea flexuosa and Antillogorgia americana, across time and geographical locations and performed network analyses to investigate potential bacterial interactions. Results demonstrated that general inferences regarding the spatial and temporal stability of octocoral-associated bacterial communities should not be made, as host-specific characteristics may influence these factors. In addition, network analyses revealed differences in the complexity of the interactions between bacteria among the octocoral species analyzed, while highlighting the presence of genera known to produce bioactive secondary metabolites in both octocorals that may play fundamental roles in structuring the octocoral-associated bacteriome. [ABSTRACT FROM AUTHOR]

Applying the emerging molecular networking strategy, an uncommon cembranoid orthoester, sarcotortin A (1), featuring a 3/14/8/5‐fused scaffold, an unusual eunicellane‐type diterpenoid, sarcotorolide A (2), and two new biscembranoids, ximaolides M and N (7 and 8), along with nine known terpenoids 3–6 and 9–13 were isolated from the Hainan soft coral Sarcophyton tortuosum. The structure and absolute configuration of all new compounds were established by a combination of spectroscopic data, X‐ray diffraction analysis, and/or quantum chemical computational approaches. The plausible biogenetic relationship among these skeletally different terpenoids was proposed and discussed. In in vitro bioassay, new compound 7 exhibited a remarkable inhibitory activity against protein tyrosine phosphatases 1B (PTP1B) with the IC50 value of 8.06 μM. In addition, compounds 4 and 10 displayed significant inhibitory effects on lipopolysaccharide (LPS)‐induced inflammatory responses in RAW264.7 macrophages cells with the IC50 values of 19.13 and 16.45 μM, respectively. Compound 9 showed interesting cytotoxicity against H1975, MDA‐MB231, A549, and H1299 cancer cell lines with IC50 values of 31.59, 34.96, 43.87, and 27.93 μM, respectively. [ABSTRACT FROM AUTHOR]

Coral reef endogenous to the Red Sea ecosystem is one of the largest globally known living reefs that are remarkably distinctive to constant high temperature and salinity. Coral microbiota is one of the most important prespectives contributing to coral survival in such conditions. Four soft corals endogenous to the eastern Red Sea side at Al Rayyis White Head, KSA were collected and identified as Litophyton sp., Sinularia sp., Xenia sp. and Sarcophyton sp. Soft corals-associated microbiota were investigated using Illumina sequencing of bacterial 16S rRNA genes. Results revealed higher bacterial diversity. Assignment of bacterial reads at the phylum level revealed the predominance of Proteobacteria in all coral-associated microbiotas followed by Bacteroidetes and Firmicutes. At the family level, Litophyton sp. was dominated by Hahellaceae, Staphylococcaceae, Prevotellaceae, Moraxellaceae and Bacteroidaceae, while Xenia sp. was dominated by Hahellaceae and Anaplasmataceae. The microbiota of Sinularia sp. were dominated by Pseudomonadaceae and Enterobacteriaceae. Sarcophyton sp. microbiota mainly include members of Enterobacteriaceae only. [ABSTRACT FROM AUTHOR]

Soft corals, recognized as sessile marine invertebrates, rely mainly on chemical, rather than physical defense, by secreting intricate secondary metabolites with plausible pharmaceutical implication. Their ecological niche encompasses a diverse community of symbiotic microorganisms which potentially contribute to the biosynthesis of these bioactive metabolites. The emergence of new viruses and heightened viral resistance underscores the urgency to explore novel pharmacological reservoirs. Thus, marine organisms, notably soft corals and their symbionts, have drawn substantial attention. In this study, the chemical composition of four Mauritian soft corals: Sinularia polydactya, Cespitularia simplex, Lobophytum patulum, and Lobophytum crassum was investigated using LC–MS techniques. Concurrently, Illumina 16S metagenomic sequencing was used to identify the associated bacterial communities in the named soft corals. The presence of unique biologically important compounds and vast microbial communities found therein was further followed up to assess their antiviral effects against SARS-CoV-2 and HPV pseudovirus infection. Strikingly, among the studied soft corals, L. patulum displayed an expansive repertoire of unique metabolites alongside a heightened bacterial consort. Moreover, L. patulum extracts exerted some promising antiviral activity against SARS-CoV-2 and HPV pseudovirus infection, and our findings suggest that L. patulum may have the potential to serve as a therapeutic agent in the prevention of infectious diseases, thereby warranting further investigation.

Antiproliferation effects of Clavularia-derived natural products against cancer cells have been reported on, but most studies have focused on identifying bioactive compounds, lacking a detailed investigation of the molecular mechanism. Crude extracts generally exhibit multiple targeting potentials for anticancer effects, but they have rarely been assessed for methanol extracts of Clavularia inflata (MECI). This investigation aims to evaluate the antiproliferation of MECI and to examine several potential mechanisms between oral cancer and normal cells. A 24 h MTS assay demonstrated that MECI decreased cell viability in several oral cancer cell lines more than in normal cells. N-acetylcysteine (NAC), an oxidative stress inhibitor, recovered these antiproliferation effects. Higher oxidative stress was stimulated by MECI in oral cancer cells than in normal cells, as proven by examining reactive oxygen species and mitochondrial superoxide. This preferential induction of oxidative stress was partly explained by downregulating more cellular antioxidants, such as glutathione, in oral cancer cells than in normal cells. Consequently, the MECI-generated high oxidative stress in oral cancer cells was preferred to trigger more subG1 population, apoptosis expression (annexin V and caspase activation), and DNA damage, reverted by NAC. In conclusion, MECI is a potent marine natural product showing preferential antiproliferation against oral cancer cells. [ABSTRACT FROM AUTHOR]

The objective of this research was to evaluate the cytotoxic activities of the fractions and isolated compounds of the soft corals Litophyton arboreum against A549, MCF-7 and HepG2 cell lines by MTT assay method, and to chemically investigate the various metabolites of its total extract using LC-HR-ESI-MS metabolomic profiling. The metabolomic profiling revealed the presence of various metabolites, mainly sesquiterpenes and steroids reported for the first time in L. arboreum. Additionally, eight compounds (1-8) have been isolated from the n-hexane-chloroform (1:1) fraction that exhibited noticeable activity towards A549, MCF-7 and HepG2 cell lines. The steroids (5 and 6), and the sesquiterpene (1) exerted noticeable activity against A549 cell line (IC50 28.5 ± 4.4, 36.9 ± 2.9 and 67.3 ± 9.9 µM/mL, respectively) compared to etoposide as standard cytotoxic agent (IC50 48.3 ± 7.6 µM/mL). Compound 6 also exhibited cytotoxicity against MCF-7 cell line (IC50 55.3 ± 4.9 µM/mL). [ABSTRACT FROM AUTHOR]

Microplastics are a persistent and ubiquitous source of pollution in the marine environment, representing a severe threat to tropical coral reefs. The effects of microplastics on reef-building (hard) corals have been documented (interference with normal digestion process, polyp retraction, oxidative stress, impairment of the photosynthetic machinery, bleaching). However, the impact of microplastics on soft corals, the second most abundant benthos of tropical reefs, remains to be thoroughly studied. In this work, we analysed the effects of a short-term microplastic exposure on the cellular physiology of the soft coral Coelogorgia palmosa. We found that samples exposed to >50 mg l−1 of microplastic showed significant increase in the activities of the antioxidant enzymes glutathione reductase, catalase, and superoxide dismutase, suggesting a rise in oxidative stress. Furthermore, exposure to microplastics increased lipid peroxidation, indicating oxidative damage. Overall, our results show that similar to hard corals, microplastic ingestion causes oxidative stress and cellular damage in soft corals. Our study provides a first assessment of physiological effects of microplastic exposure on the soft coral, Coelogorgia palmosa, highlighting the need for further investigations about these contaminants and their influence on marine benthic fauna. Such information is crucial to understand how different reef organisms respond to microplastic pollution and who the ecological winners or losers will be in an increasingly polluted marine environment. Key policy highlights The effect of microplastic contamination at the cellular and molecular level has never been investigated before in alcyonacean corals. Concentrations of 50–70 mg l−1 of polyethylene caused significant rise in oxidative stress in Coelogorgia palmosa after 48 h. After 48 h exposure to 50 mg l−1 significant oxidative damage was recorded. No significant modulation in the expression of the cytoprotective protein Hsp60 was observed after exposure to microplastics. [ABSTRACT FROM AUTHOR]

The geographic partition of genetic variation, also known as population structure, is an essential attribute of a species' biology and a useful tool for resource managers to make informed decisions for the protection and long-term preservation of the species. Among the most severe deteriorations of coral reefs have been recorded in the Caribbean Sea and such biological knowledge from key species could assist stakeholders to construct sound management plans. The population structure of the iconic Caribbean Sea fan, Gorgonia ventalina Linnaeus, 1758, was estimated from DNA sequences of the mitochondrial marker MutS Like Homolog protein 1 (MSH1) and the nuclear marker Signal Recognition Particle 54 intron (SRP54). Samples encompassed most of the species' known distribution from Curaçao to Florida, the Lesser Antilles to Panamá, and Bermuda. Analysis of molecular variance revealed a significant amount of population differentiation between the eastern and western Caribbean with the MSH1 gene, however, no such signal was detected with the SRP54 intron. The Old Buoy and Mario reefs of western and southwestern Puerto Rico were the most genetically differentiated among all sites based on the MSH1 gene. Local current patterns at the reef level and low sample sizes are possible explanations for the observed patterns of genetic differentiation. Comparisons with other studies using microsatellites and SNPs, including a study with G. ventalina suggests that faster-evolving genomic areas are more appropriate markers for the detection of fine-scale population differentiation in G. ventalina. [ABSTRACT FROM AUTHOR]

The Ægir Ridge System (ARS) is an ancient extinct spreading axis in the Nordic seas extending from the upper slope east of Iceland (~550 m depth), as part of its Exclusive Economic Zone (EEZ), to a depth of ~3,800 m in the Norwegian basin. Geomorphologically a rift valley, the ARS has a canyon-like structure that may promote increased diversity and faunal density. The main objective of this study was to characterize benthic habitats and related macro- and megabenthic communities along the ARS, and the influence of water mass variables and depth on them. During the IceAGE3 expedition (Icelandic marine Animals: Genetics and Ecology) on RV Sonne in June 2020, benthic communities of the ARS were surveyed by means of a remotelyoperated vehicle (ROV) and epibenthic sledge (EBS). For this purpose, two working areas were selected, including abyssal stations in the northeast and bathyal stations in the southwest of the ARS. Video and still images of the seabed were usedtoqualitatively describebenthic habitats based on the presence of habitat-forming taxa and the physical environment. Patterns of diversity and community composition of the soft-sediment macrofauna, retrieved from the EBS, were analyzed in a semiquantitative manner. These biological data were complemented by producing high-resolution bathymetric maps using the vessel's multi-beam echosounder system. As suspected, we were able to identify differences in species composition and number of macro- and megafaunal communities associated with a depth gradient. A biological canyon effect became evident in dense aggregates of megafaunal filter feeders and elevated macrofaunal densities. Analysis of videos and still images from the ROV transects also led to the discovery of a number ofVulnerable Marine Ecosystems (VMEs) dominated by sponges and soft corals characteristic of the Arctic region. Directions for future research encompass a more detailed, quantitative study of the megafauna and more coherent sampling over the entire depth range in order to fully capture the diversity of the habitats and biota of the region. The presence of sensitive biogenic habitats, alongside seemingly high biodiversity and naturalness are supportive of ongoing considerations of designating part of the ARS as an ''Ecologically and Biologically Significant Area'' (EBSA). [ABSTRACT FROM AUTHOR]

Soft corals are considered as a prospective resource for the isolation of natural product antifoulants. In this study, the temporal variations in the antifouling activity of the crude extract of the soft coral Sarcophyton trocheliophorum samples collected from the Jeddah coast of Saudi Arabia during summer (June–August 2018) and winter seasons (December 2018–February 2019) were assessed using laboratory tests. The crude extract was tested against biofilm-forming bacteria and barnacle larvae in the laboratory. The results indicated significant variations (P < 0.001) in the antifouling activity of the extracts between the samples collected during the summer and winter seasons. The extract of the soft coral samples collected during the summer season showed higher inhibitory activity against the fouling bacteria and barnacle larva. In addition, the surface-associated bacteria abundance on the soft corals were analysed and the results showed higher abundance on winter season samples. Further, GC–MS analysis indicated differences in the metabolite composition with the abundance of compounds such as cis-z-a-Bisabolene epoxide and caryophyllene oxide being high in summer samples and Isoaromadendrene epoxide and β-cembrenediol showing a higher peak area percentage in winter samples. Overall, this study revealed temporal variations in the antifouling activity and metabolite composition of the Red Sea soft corals. [ABSTRACT FROM AUTHOR]

The ethanolic extracts of eight soft corals and five sponges were screened for antifungal activity (AU) against pathogenic fungi infected corals. The data revealed that the AUs, recorded by different crude extracts (ethanol and ethyl acetate) of soft corals, ranged between 0.0 and 49.0, which was achieved by the extract of S. gracile against A. fumigatus. In addition, the values of AUs, recorded by different crude extracts (ethanol and ethyl acetate) of sponge species, revealed that the AU ranged between 0.0 and 36.0, which was achieved by extract of Suberea mollis Row against P. auratiogriseum. Cleary, our findings proved that both ethanolic and ethyl acetate extracts of soft corals (S. polydactyla, S. gracile, S. glaucum, S. trocheliophorum, S. ehrenbergi, and X. macrospiculata) were the most effective extracts that exhibited the most potent AUs. Moreover, the most effective extracts were tested to determine the MICs against the most affected fungi and the lowest effective MIC was 10 mg/mL against several pathogenic fungi. On the other hand, the GC/MS profiles of the most effective extracts were: fatty acids and their derivatives, terpenoid (Nootkaton-11,12-epoxide, caryophyllene, geranyl-a-terpinene, etc.), steroid (corticosterone, cis-calamenene, etc.), and others. An additional trail proved the efficacy of palmitic acid (as a potent example of bioactive constituents found in crude extracts) when was compared to Treflucan. [ABSTRACT FROM AUTHOR]

Octocorals are relatively understudied than other coral reef organisms despite their ecological and economic values. The Philippines is known to have high marine biodiversity, but information on octocorals is lacking. This study investigated spatial and temporal variations in the assemblage of octocorals in selected reef sites in the West Philippine Sea (WPS)- the Kalayaan Island Group (i.e., Pag-asa, Sabina, Lawak, and Northeast Investigator) and Ulugan in 2017 and 2019. Results showed high octocoral taxonomic richness (at least 10 families) in the study sites. Mean percent octocoral cover in WPS was 5.35% SE ± 0.55, with Sabina having the highest octocoral cover in both years. Significant differences in octocoral cover were observed among sites in both years, but among-station differences were only observed in 2017. Octocoral assemblage also differed among sites in both years (ANOSIM: R > 0.5, p < 0.05), wherein different octocoral taxa dominated in different sites. In particular, variations were driven by high cover of holaxonians, nephtheids, and coelogorgiids in Sabina, and clavulariids, tubiporiids, and xeniids in Northeast Investigator in 2017. In 2019, significant variations were driven by high cover of helioporiids in Pag-asa, while Sabina had higher abundance of holaxonians, nephtheids, alcyoniids, and xeniids. Short-term temporal variation on octocoral cover in monitoring stations in Pag-asa was not observed (Kruskal-Wallis, p > 0.05), although the overall mean octocoral cover increased from 1.23% ± SE 0.47 in 2017 to 2.09% SE ± 0.37 in 2019. Further, there was no significant change in the octocoral assemblage in Pag-asa between years (ANOSIM, R = 0.11, p = 0.07). This study highlights high octocoral taxonomic richness in the WPS relative to other sites in the Indo-Pacific Region and provides baseline information on the octocoral assemblages, which can be useful for future ecological studies and marine biodiversity conservation efforts.

Invasive species are leading to ecosystem changes and socioeconomic deterioration around the globe. In 2018, unknown soft corals were noticed forming a massive 'blue carpet' on a shallow reef environment at Todos os Santos Bay, South-west Atlantic. In this study we identified the species, quantified their distribution and abundance as a first step for baseline invasion monitoring, and discussed origin, vector and impacts on native competitors. Coral samples were identified based on morphology and a multilocus DNA barcode, and benthic structure was characterized using digital photoquadrats. Our results revealed two new harmful non-native octocorals in this tropical rocky reef, the 'blue polyps' genus Sarcothelia (Xeniidae), native to Hawaii but likely an undescribed cryptic species, and Briareum hamrum (Briareidae), native to the Indian Ocean. Sarcothelia sp. was the dominant taxon in the rocky reef (mean cover 23.66% ± 21.46), exhibiting high coverage as well in the sandy and patch reef habitats (15.83% ± 15.81), however, only three colonies of B. hamrum were found, all outside the sampling area. These octocorals were in physical contact with native benthic organisms, mainly with the most abundant group, but apparently avoid turf algae in sandy and patch reef habitats. We suggest that irresponsible marine aquarium releases likely introduced these species to Brazilian reefs. After identifying the aquarium trade as the main vector of octocoral introductions, we reinforce the importance of inspecting marine species importation and the urgent need to implement a government plan to mitigate invasive species' impacts on the natural reefs of Brazil. [ABSTRACT FROM AUTHOR]

Octocorallia (Cnidaria, Anthozoa) comprising over 3,600 nominal species within three orders, Alcyonacea, Helioporacea and Pennatulacea, is one of the most poorly known groups of marine invertebrates. Half of known octocoral species occur in the Indo-Pacific, but not much is understood about research efforts and outputs in this region, particularly in the Asian context. A review of the literature on Asian octocorals during a 40-year period from 1978 to 2018 revealed that most research was concentrated in particular regions/countries. An analysis of research originating from India indicated several issues, including low quality data and local taxonomic impediment. This paper examines the general trends and geographic disparity in Asian octocoral research over the past four decades, analyses the extent and source of such disparity by drawing parallels between India and the rest of Asia, and provides recommendations for improving octocoral studies in the region.

Antiproliferation effects of Clavularia-derived natural products against cancer cells have been reported on, but most studies have focused on identifying bioactive compounds, lacking a detailed investigation of the molecular mechanism. Crude extracts generally exhibit multiple targeting potentials for anticancer effects, but they have rarely been assessed for methanol extracts of Clavularia inflata (MECI). This investigation aims to evaluate the antiproliferation of MECI and to examine several potential mechanisms between oral cancer and normal cells. A 24 h MTS assay demonstrated that MECI decreased cell viability in several oral cancer cell lines more than in normal cells. N-acetylcysteine (NAC), an oxidative stress inhibitor, recovered these antiproliferation effects. Higher oxidative stress was stimulated by MECI in oral cancer cells than in normal cells, as proven by examining reactive oxygen species and mitochondrial superoxide. This preferential induction of oxidative stress was partly explained by downregulating more cellular antioxidants, such as glutathione, in oral cancer cells than in normal cells. Consequently, the MECI-generated high oxidative stress in oral cancer cells was preferred to trigger more subG1 population, apoptosis expression (annexin V and caspase activation), and DNA damage, reverted by NAC. In conclusion, MECI is a potent marine natural product showing preferential antiproliferation against oral cancer cells.