Tubastraea Tagusensis Research Articles

Electric underwater tools for sun coral management

Sun coral, identified as Tubastraea coccinea and Tubastraea tagusensis, are invasive marine species originally from the Pacific Ocean that have become a significant threat to native biodiversity and ecosystems in Brazil. The rapid growth and unique reproduction strategies of Tubastraea species have facilitated their success as invasive species. In the past two decades, Brazil has experienced a notable loss of biodiversity, partially attributed to invasive species, as reported by the Brazilian Platform on Biodiversity and Ecosystem Services. Current management efforts primarily involve manual removal, often employing sledgehammers and chisels, carried out by environmental government agencies, in partnership with NGOs and volunteers. However, the need for more efficient management strategies emphasizes the important role of engineering and technology in improving environmental management. To address this issue, our work focuses on the development and prototyping of two underwater tools: an impact hammer and a rotating brush. These tools are designed with ergonomic features, operating time, and size considerations suitable for use by SCUBA divers. Our prototypes have successfully met the required specifications and offer potential for large-scale manufacturing, promising more effective measures for controlling invasive sun coral in Brazil.

Spread of the invasive corals, Tubastraea coccinea and Tubastraea tagusensis, towards the lower intertidal zones of southeastern Brazil

Photographs were obtained of two invasive species of sun corals (Tubastraea tagusensis and Tubastraea coccinea) covering rocky substrates, in Ilha Grande Bay, Rio de Janeiro/Brazil, that are exposed, out of seawater, during low tide. The images highlight secretion of mucus, distention of tentacles, and partial loss of soft tissue.

Priority effects, environmental filtering and neutral coexistence explain large- to small-scale distribution of invasive sun corals in the SW Atlantic

Two sun coral species, Tubastraea tagusensis and T. coccinea, have successfully colonized reef habitats along the Southwest Atlantic. However, their invasive biology has been largely addressed without considering species-specific distribution patterns. Here, we assessed the distribution and abundance of Tubastraea spp. at vertical rocky reef sites within a number of islands along 120 km of coastline off the northern coast of São Paulo State, Brazil, to (1) investigate possible mechanisms underlying the invasion dynamics in the region, (2) test species-specific distributions according to a key environmental filter (depth), and (3) examine within-patch patterns to assess whether competition, niche-based or neutral processes are best candidates to modulate local species coexistence. Sun corals were found in the great majority of the studied locations, and the probability of finding them at any given reef site was estimated to be 0.54. There was substantial species segregation across locations, consistent with primary priority effects. Within locations, results suggest environmental filtering, with T. coccinea apparently advantaged in more hydrodynamic environments just below the surf zone. At sun coral patches with extensive co-occurrence of T. tagusensis and T. coccinea, the presence of each species can be, remarkably, modeled as an independent event, suggesting neutral coexistence. The spread of sun corals is an ongoing and increasingly invasive process that may be explained by the enemy-release hypothesis and the lack of negative interactions between Tubastraea species. The stochastic nature of small-scale distributions sets an additional challenge to predict (and thus control) sun coral invasion.

Mitochondrial Imbalance of Trypanosoma cruzi Induced by the Marine Alkaloid 6-Bromo-2'-de-N-Methylaplysinopsin.

Chagas disease, caused by Trypanosoma cruzi, affects seven million people worldwide and lacks effective treatments. Using bioactivity-guided fractionation, NMR, and electrospray ionization-high resolution mass spectrometry (ESI-HRMS) spectral analysis, the indole alkaloid 6-bromo-2′-de-N-methylaplysinopsin (BMA) was isolated and chemically characterized from the marine coral Tubastraea tagusensis. BMA was tested against trypomastigotes and intracellular amastigotes of T. cruzi, resulting in IC50 values of 62 and 5.7 μM, respectively, with no mammalian cytotoxicity. The mechanism of action studies showed that BMA induced no alterations in the plasma membrane permeability but caused depolarization of the mitochondrial membrane potential, reducing ATP levels. Intracellular calcium levels were also reduced after the treatment, which was associated with pH alteration of acidocalcisomes. Using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF)/MS analysis, alterations of mass spectral signals were observed after treatment with BMA, suggesting a different mechanism from benznidazole. In silico pharmacokinetic–pharmacodynamic (PKPD) parameters suggested a drug-likeness property, supporting the promising usefulness of this compound as a new hit for optimizations.

Western Atlantic invasion of sun corals: incongruence between morphology and genetic delimitation among morphotypes in the genus Tubastraea

The scleractinian corals of the genus Tubastraea Lesson, 1830 are currently globally dispersed and even so still present a confused taxonomy due to the overlap of morphological characters between the species. In this study, we investigate Tubastraea species previously found in the western Atlantic, based on the molecular marker (ITS gene) and morphology, to determine the accuracy of their descriptions. We identified three morphotypes from Brazil which were genetically delimited into two species: Tubastraea coccinea (Morphotypes I and II) and Tubastraea sp. (Morphotype III). Although morphotype I has morphological patterns of Tubastraea aurea (Quoy & Gaimard, 1833) there was no molecular divergence to support the species differentiation and continue to be recognized as a morphological variant of T. coccinea. The third morphotype is both morphologically and genetically distinct from T. coccinea and is also not representative of the species Tubastraea tagusensis Wells, 1982 despite earlier descriptions describing T. tagusensis in Brazil. Morphotype III exhibited distinct morphological characteristics among the other morphotypes, mainly due to greater polyp projection. In addition, it has fusions between septa, a characteristic that differentiates it from T. tagusensis. Nevertheless, molecular phylogenetic analyses showed that Brazilian Tubastraea fell into two well-supported monophyletic clades, and samples collected in the United States overlapped in both clades. Florida samples exhibited fewer morphotypes and showed greater genetic diversity, presenting haplotypes in four other internal clades. This study highlights the need for an integrative approach to conduct a deeper species delimitation of Tubastraea, essential for managing bioinvasion events by sun corals.

Alien hotspot: Benthic marine species introduced in the Brazilian semiarid coast

In this study, we provide a baseline assessment of introduced marine species along the extensive (~600 km) Brazilian semiarid coast. We reported 27 introduced and 26 cryptogenic species. Moreover, the main vectors of introduction were ballast water, shipping lines, oil and gas activities, biofouling, and rafting on plastic debris. The taxa were Ascidiacea (17 species) and Bryozoa (17), followed by Crustacea (6), Mollusca (6), Cnidaria (3), Echinodermata (3), and Porifera (1). Among these invertebrates, some species are recognized as drivers of impacts such as the invasive corals (Tubastraea tagusensis and Tubastraea coccinea), the bivalves Isognomom bicolor and Perna viridis, the crab Charybdis hellerii, the brittle star Ophiothela mirabilis, and, finally, the bryozoan Membraniporopsis tubigera. These species threaten the biodiversity of unique ecosystems such as intertidal sandstone reefs, shallow-water coral reefs, and mesophotic ecosystems. Moreover, the up-to-date results highlight that this region is a hotspot of bioinvasion in the tropical South Atlantic.

The microbial profile of a tissue necrosis affecting the Atlantic invasive coral Tubastraea tagusensis

The Southwestern Atlantic rocky reef ecosystems are undergoing significant changes due to sun-corals (Tubastraea tagusensis and T. coccinea) invasion. At Búzios Island, on the northern coast of São Paulo State, where the abundance of T. tagusensis is particularly high, some colonies are displaying tissue necrosis, a phenomenon never reported for this invasive nor any other azooxanthellate coral species. Using next-generation sequencing, we sought to understand the relationship between T. tagusensis tissue necrosis and its microbiota. Thus, through amplicon sequencing, we studied both healthy and diseased coral colonies. Results indicate a wide variety of bacteria associated with healthy colonies and an even higher diversity associated with those corals presenting tissue necrosis, which displayed nearly 25% more microorganisms. Also, as the microbial community associated with the seven healthy colonies did not alter composition significantly, it was possible to verify the microbial succession during different stages of tissue necrosis (i.e., initial, intermediate, and advanced). Comparing the microbiome from healthy corals to those in early tissue necrosis suggests 21 potential pathogens, which might act as the promoters of such disease.

Retirement risks: Invasive coral on old oil platform on the Brazilian equatorial continental shelf

The objective of this study was to report, for the first time, the presence of an invasive coral (Tubastraea tagusensis) in an oil platform on the Brazilian equatorial continental shelf. This structure is located more than 1200 km north from other oil and gas structures colonized by this coral. We also discussed the retirement and decommissioning of old biofouling-encrusted oil and gas platforms (~62 platforms) from decreased production and the current oil crisis, exacerbated by the COVID-19 pandemic. This presents an ecological concern due invasive coral range expansion and potential impacts to poorly studied ecosystems such as marginal shallow-water coral reefs and mesophotic ecosystems. It is imperative that mindful risk analysis and rigorous environmental studies must precede the installation of new oil and gas platforms. In addition, decommissioning of retired structures should take into consideration marine restoration and non-indigenous species dispersal, and more specifically, Tubastraea bioinvasion.

A Method to Assess the Risk of Sun Coral Invasion in Marine Protected Areas.

The safest and most efficient method of avoiding costs and impacts associated with biological invasions is to prevent the introduction and establishment of non-native species. In Brazil, two invasive coral species have been causing ecological, economic and social impacts: Tubastraea coccinea and Tubastraea tagusensis. This work presents a protocol to analyze the risk of invasion in Marine Protected Areas (MPAs) in the State of Rio de Janeiro considering the main vector of these species on the Brazilian coast. This protocol takes five risk factors into account: environmental similarity between the donor area and the possible receiving area; available substrate for colonization; proximity to the donor region; proximity and quantity of oil platforms and drill ships that passed by the analyzed MPAs and proximity and quantity of oil platforms and drill ships that anchored near the MPAs. Results must be used by decision-makers for a better management of Marine Protected Areas. The protocol we present can be applied to analyze the relative risk of invasion throughout the Brazilian coast, in order to prioritize areas for early detection and monitoring of the presence of sun corals.

Microbiome of the Southwestern Atlantic invasive scleractinian coral, Tubastraea tagusensis

BackgroundCommonly known as sun-coral, Tubastraea tagusensis is an azooxanthellate scleractinian coral that successfully invaded the Southwestern Atlantic causing significant seascape changes. Today it is reported to over 3500 km along the Brazilian coast, with several rocky shores displaying high substrate coverage. Apart from its singular invasiveness capacity, the documentation and, therefore, understanding of the role of symbiotic microorganisms in the sun-coral invasion is still scarce. However, in general, the broad and constant relationship between corals and microorganisms led to the development of co-evolution hypotheses. As such, it has been shown that the microbial community responds to environmental factors, adjustment of the holobiont, adapting its microbiome, and improving the hosts’ fitness in a short space of time. Here we describe the microbial community (i.e. Bacteria) associated with sun-coral larvae and adult colonies from a locality displaying a high invasion development.ResultsThe usage of high throughput sequencing indicates a great diversity of Bacteria associated with T. tagusensis, with Cyanobacteria, Proteobacteria, Bacteroidetes, Actinobacteria, Planctomycetes, and Firmicutes corresponding to the majority of the microbiome in all samples. However, T. tagusensis’ microbial core consists of only eight genera for colonies, and, within them, three are also present in the sequenced larvae. Overall, the microbiome from colonies sampled at different depths did not show significant differences. The microbiome of the larvae suggests a partial vertical transfer of the microbial core in this species.ConclusionAlthough diverse, the microbiome core of adult Tubastraea tagusensis is composed of only eight genera, of which three are transferred from the mother colony to their larvae. The remaining bacteria genera are acquired from the seawater, indicating that they might play a role in the host fitness and, therefore, facilitate the sun-coral invasion in the Southwestern Atlantic.

Shipwrecks help invasive coral to expand range in the Atlantic Ocean

The invasive coral Tubastraea tagusensis (sun coral) is a habitat-forming species currently increasing its geographical range into the Atlantic Ocean, thereby causing negative ecological and socioeconomic impacts. Scuba divers observed this coral in the western equatorial Atlantic in January 2020, growing at high densities on a shipwreck from World War II (sunk in 1943) at a depth of approximately 32 m. Available footage from the beginning of the decade (2012–2018) shows no obvious signs of sun coral on this shipwreck, suggesting recent colonization and range expansion. The recent evidence of expansion was found 200 km east of the last record, which was also found on a WWII shipwreck (sunk in 1942) in 2016. We have identified hundreds of overlooked WWII shipwrecks, as well as new wrecks in shallow and mesophotic waters, that may provide stepping-stone habitats for this coral to expand its distribution in the Atlantic. We discuss the role of shipwrecks as a network of stepping stones for the sun coral spread, creating complementary paths for the invasiveness by overcoming physiological traits and the short lifespan of the coral larvae. Previous research underestimates the importance of these artificial stepping-stone patches in sustaining crucial dispersal events and range expansion of invasive species. These results are a call to action to manage the invasive Tubastraea corals at a national and international scale in the Atlantic basin.

Anti-inflammatory potential of invasive sun corals (Scleractinia: Tubastraea spp.) from Brazil: alternative use for management?

The objective was to analyse the anti-inflammatory potential of the invasive coral species Tubastraea coccinea and Tubastraea tagusensis. Methanolic extracts, fractions and synthesized compounds were evaluated for their anti-inflammatory ability, and their composition was elucidated through chemical analysis. The genus Tubastraea (Order Scleractinia, Family Dendrophylliidae) (known as sun corals) presents compounds with pharmacological value. The introduction of these azooxanthellate hard corals into Brazil, initially in Rio de Janeiro state, occurred through their fouling of oil and gas platforms from the Campos oil Basin. The two invasive species have successfully expanded along the Brazilian coast and threaten endemic species and biodiversity. The HPLC-MS and GC-MS data suggest the presence of aplysinopsin analogues (alkaloids). Anti-inflammatory activity was observed in all samples tested in in-vivo assays, especially in T.coccinea. The ethyl acetate fraction from this sample was more effective in in-vitro assays for anti-inflammatory activity. Depending on the concentration, this fraction showed cytotoxic responses. These species have potential pharmacological use, and considering their invasive nature, this study presents a potential alternative use, which may enhance the management of this biological invasion.

Hiding in plain sight: invasive coral Tubastraea tagusensis (Scleractinia:Hexacorallia) in the Gulf of Mexico

Our research presents the first record of Tubastraea tagusensis (Wells, Notes on Indo-Pacific scleractinian corals. Part 9. New corals from the Galapagos Islands, 1982) in the Gulf of Mexico. Specimens of Tubastraea were collected from various artificial reefs. Morphological analyses of these specimens show that there are three distinct lineages of Tubastraea that have remained cryptic due to similar morphology in the field: Tubastraea coccinea (Lesson, 1829), T. tagusensis, and a third clade containing a mix of characters of the former two. These results based on morphology are corroborated by phylogenetic and haplotype analyses using a partial sequence of the mitochondrial genes ATP8 and cytochrome oxidase I (mtCOI). The negative effects on natural habitats by invasive species of Tubastraea have been documented worldwide. Therefore, it is imperative to implement management policies that will help prevent the expansion of these species into natural habitats in the Gulf of Mexico. The essential first step is accurate identification to determine possible sources, vectors, and current expansion rates. We present a clear set of morphological characters and a genetic marker to help distinguish between these three cryptic lineages.

Invasive Tubastraea spp. and Oculina patagonica and other introduced scleractinians corals in the Santa Cruz de Tenerife (Canary Islands) harbor: Ecology and potential risks

In this study the presence, distribution and density of several species of Scleractinia corals introduced in the Canary Islands and settled in artificial substrata (marina pontoons and port docks) of the Santa Cruz de Tenerife harbor were studied. Tubastraea spp. and Oculina patagonica densities in such locations were assessed owing to their potential as invasive species, and the abundance of other introduced and native corals was also estimated. O. patagonica showed a high frequency of occurrence (28.8%), reaching densities of 0.25 colonies/m2 and was exclusively located in the marina pontoons, found opposite the anchoring spots of oil platforms, mainly in shaded environments. Tubastraea spp. were also found in said area, where they showed very high densities (44.6% of frequency and 2.0 colonies/m2) regardless of light availability, as well as in the inner wall of another port dock where oil platforms berth. Other species were only recorded in the pontoon areas of the marina, with the occurrence of the Culicia genus especially remarkable (15.9%), whose only previous record in the Atlantic was in the Cape of Good Hope (South Africa). Tubastraea tagusensis was also recorded for the first time in the eastern Atlantic. Results confirm that oil platforms have been the introductory vector of non-native corals and the introduction process, the expansion and invasion risks, as well as the need for a control plan are discussed.

Northward range expansion of the invasive coral (Tubastraea tagusensis) in the southwestern Atlantic

Invasive species are recognized as a major threat to marine biodiversity. The scleractinian coral Tubastraea tagusensis has been expanding its range into the southwest Atlantic Ocean, causing negative impacts on marine ecosystems. In 2016, the species was recorded on a shipwreck located 40 km off the Brazilian coast of Ceara State (latitude 2°30′ S), at densities ranging from 16 to 872 colonies × m−2. This is the first documented occurrence and density of T. tagusensis in the northern region of Brazilian coral reefs (NBR), expanding the range of the genus along the Brazilian coastline to ca. 3850 km. Here it may form a threat to marine environments such as coral reefs, rocky shores, mussel beds, and fouling communities on manmade structures. Considering that the NBR contains vulnerable marine ecosystems, such as the reef system off the Amazon River, and that it is connected by both the North Brazil Current and shipping lanes associated with oil and gas platforms, a monitoring programme is needed to study the population dynamics of this invasive species.

New records of the alien cup-corals (Tubastraea spp.) within estuarine and reef systems in Todos os Santos Bay, Southwestern Atlantic

The alien cup-coral Tubastraea spp. has been increasingly reported in the Southwestern Atlantic since the 1980s. More recently it was observed on the East coast of Brazil, the area with the highest biodiversity in the Southwest Atlantic. In the present study, we report the actual distribution of Tubastraea tagusensis and Tubastraea coccinea around Todos os Santos Bay (TSB), an important system in the Southwest Atlantic coast. We mapped the geographic expansion of Tubastraea tagusensis and Tubastraea coccinea at 11 sites in estuarine and 2 in reef systems at TSB. The findings from our study will contribute to monitor alien expansion and implement management actions to control these invasions on the Brazilian coast.

Complete mitochondrial genome sequences of Atlantic representatives of the invasive Pacific coral species Tubastraea coccinea and T. tagusensis (Scleractinia, Dendrophylliidae): Implications for species identification

Members of the azooxanthellate coral genus Tubastraea are invasive species with particular concern because they have become established and are fierce competitors in the invaded areas in many parts of the world. Pacific Tubastraea species are spreading fast throughout the Atlantic Ocean, occupying over 95% of the available substrate in some areas and out-competing native endemic species. Approximately half of all known coral species are azooxanthellate but these are seriously under-represented compared to zooxanthellate corals in terms of the availability of mitochondrial (mt) genome data. In the present study, the complete mt DNA sequences of Atlantic individuals of the invasive scleractinian species Tubastraea coccinea and Tubastraea tagusensis were determined and compared to the GenBank reference sequence available for a Pacific “T. coccinea” individual. At 19,094bp (compared to 19,070bp for the GenBank specimen), the mt genomes assembled for the Atlantic T. coccinea and T. tagusensis were among the longest sequence determined to date for “Complex” scleractinians. Comparisons of genomes data showed that the “T. coccinea” sequence deposited on GenBank was more closely related to that from Dendrophyllia arbuscula than to the Atlantic Tubastraea spp., in terms of genome length and base pair similarities. This was confirmed by phylogenetic analysis, suggesting that the former was misidentified and might actually be a member from the genus Dendrophyllia. In addition, although in general the COX1 locus has a slow evolutionary rate in Scleractinia, it was the most variable region of the Tubastraea mt genome and can be used as markers for genus or species identification. Given the limited data available for azooxanthellate corals, the results presented here represent an important contribution to our understanding of phylogenetic relationships and the evolutionary history of the Scleractinia.

Effects of the alien coral Tubastraea tagusensis on native coral assemblages in a southwestern Atlantic coral reef

The alien coral Tubastraea spp. has invaded Atlantic coral reefs since 1940s, but their effects on native coral assemblages are poorly understood. In this study the effects on coral assemblage structure and tissue mortality in native competitors by alien coral were investigated. We compared native coral cover in zones with and without T. tagusensis and evaluated the mortality of native coral species in natural encounters with T. tagusensis. Additionally, we evaluated the effects of contact with this invader on two native corals, Siderastrea stellata and Montastraea cavernosa, using a manipulative experiment. Multivariate analyses detected significant differences between coral assemblages in invaded and non-invaded zones. In the invaded zone, we observed greater cover of T. tagusensis on reef walls (34.9 ± 4.2 %) than on reef tops (18.5 ± 4.1 %). Madracis decactis and Mussismilia hispida were significantly less abundant in invaded zone than in non-invaded zones at the reef walls. Manipulative experiments showed a significant increase in tissue mortality of S. stellata (3.2 ± 1.4 cm2) after 60 days of contact with T. tagusensis and no effects on M. cavernosa after 90 days of contact. In natural encounters, 52 and 0.1 % of the S. stellata and M. cavernosa colonies, respectively, showed tissue mortality. These results indicate that competitive interactions with native competitors are important to understand alien coral establishment on coral reef. Our study documents the negative effects of the alien coral on coral reef assemblages and reinforces the urgent need for monitoring and management actions to control the expansion of this invader on Brazilian reefs.

Occurrence of an invasive coral in the southwest Atlantic and comparison with a congener suggest potential niche expansion.

Tubastraea tagusensis, a coral native to the Galapagos Archipelago, has successfully established and invaded the Brazilian coast where it modifies native tropical rocky shore and coral reef communities. In order to understand the processes underlying the establishment of T. tagusensis, we tested whether Maxent, a tool for species distribution modeling, based on the native range of T. tagusensis correctly forecasted the invasion range of this species in Brazil. The Maxent algorithm was unable to predict the Brazilian coast as a suitable environment for the establishment of T. tagusensis. A comparison between these models and a principal component analysis (PCA) allowed us to examine the environmental dissimilarity between the two occupied regions (native and invaded) and to assess the species' occupied niche breadth. According to the PCA results, lower levels of chlorophyll-a and nitrate on the Atlantic coast segregate the Brazilian and Galapagos environments, implying that T. tagusensis may have expanded its realized niche during the invasion process. We tested the possible realized niche expansion in T. tagusensis by assuming that Tubastraea spp. have similar fundamental niches, which was supported by exploring the environmental space of T. coccinea, a tropical-cosmopolitan congener of T. tagusensis. We believe that the usage of Maxent should be treated with caution, especially when applied to biological invasion (or climate change) scenarios where the target species has a highly localized native (original) distribution, which may represent only a small portion of its fundamental niche, and therefore a violation of a SDM assumption.

A test of the efficacy of wrapping to manage the invasive corals Tubastraea tagusensis and T. coccinea

Tubastraea tagusensis and T. coccinea (Scleractinia: Dendrophylliidae) are two corals that have invaded and impacted the southwest Atlantic since the 1980s. Here, we investigated experimentally the use of plastic and raffia sheets, simulating the use of wraps, as an effective method to kill the invasive corals. We showed that by seven days all polyps of the invasive corals were dead in both treatments, probably from lack of oxygen, food and/or due to physical attrition with the wraps. Tubastraea tagusensis was more resistant than T. coccinea, probably due to its different form. The use of plastic sheets was found to be more efficient for killing but raffia was easier to manipulate underwater and allowed an extended period for decomposition of the corals tissues. The use of wraps was demonstrated to be an efficient way of killing and may be added to the management toolbox for the control and eradication of Tubastraea spp. along with fresh water treatment and manual removal.