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Abstract Marine invertebrates represent an underexplored reservoir for actinobacteria, which are known to synthesize novel bioactive compounds. This study isolated 37 actinobacterial strains from five distinct marine invertebrate hosts, namely Chondrilla australiensis, Palythoa sp., Favia sp., Porites lutea, and Acropora cervicornis, while no strains were obtained from Lissoclinum sp. and Lithophyllon sp. These isolates were taxonomically classified into six genera: Gordonia, Microbacterium, Micromonospora, Nocardia, Rhodococcus, and Streptomyces, with Streptomyces and Micromonospora being notably predominant. Comparative genomic analysis facilitated the identification of two novel species: Micromonospora palythoicola sp. nov. (strain S2-005T = TBRC 18343T and NBRC 116545T) and Streptomyces poriticola sp. nov. (strain C6-003T, =TBRC 17807T and NBRC 116425T). Both species exhibited substantial genetic differences from their nearest known species as demonstrated by digital DNA-DNA hybridization and average nucleotide identity scores, which fell below the thresholds of 70% and 95%, respectively. Streptomyces poriticola C6-003T displayed significant antimicrobial activity and selective cytotoxicity against human breast cancer MCF-7 cells, with reduced toxicity towards human dermal papilla cells. Micromonospora palythoicola S2-005T manifested antimicrobial properties against Streptococcus mutans and Kocuria rhizophila. These findings highlight the considerable diversity of actinobacteria within marine invertebrates and underscore their potential as a source of new species with promising biological properties for therapeutic applications.

Zoanthids, an order of cnidarians, are the main components of coral reefs around the world. However, because of the wide variety of features in this order, the use of molecular methods, it is necessary to use molecular methods for precise identification of species. Although some previous studies have been conducted in the Persian Gulf and Gulf of Oman, the diversity of zoanthids in these seas remains unknown. Therefore, the zoanthids occurring in shallow coral reefs (three meters) in three Iranian islands (Farur, Bani Farur, Hormuz) across the northern Persian Gulf and in Chabahar Bay in the Gulf of Oman were identified using molecular tools. The collected specimens were transferred alive to the laboratory, and DNA extraction was undertaken by the Chelex method. Then mitochondrial 16S rRNA and COI gene fragments were amplified using the PCR method and sequenced. The results revealed that Zoanthus sansibaricus was the dominant species in all three islands in the Persian Gulf. Z. sansibaricus and Palythoatuberculosa were reported on Farur and Bani Farur islands. P. aff. mutuki and P. tuberculosa were only recorded in Chabahar Bay. Unlike P. aff. mutuki, presence of other species identified in this study has been previously reported from the Indian and Pacific Oceans. The Palythoa genus was identified on Hormuz Island. In this study, the Zoantharia of Chabahar Bay in the Oman Sea as well as Zoantharia of Bani Farur and Farur islands were identified for the first time. [ABSTRACT FROM AUTHOR]

Abstract Mucus, produced by Palythoa caribaeorum has been popularly reported due to healing, anti-inflammatory, and analgesic effects. However, biochemical and pharmacological properties of this mucus remains unexplored. Therefore, the present study aimed to study its proteome profile by 2DE electrophoresis and MALDI-TOF. Furthermore, it was evaluated the cytotoxic, antibacterial, and antioxidant activities of the mucus and from its protein extract (PE). Proteomics study identified14 proteins including proteins involved in the process of tissue regeneration and death of tumor cells. The PE exhibited cell viability below 50% in the MCF-7 and S-180 strains. It showed IC50 of 6.9 μg/mL for the J774 lineage, and also, favored the cellular growth of fibroblasts. Furthermore, PE revealed activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus epidermidis (MIC of 250 μg/mL). These findings revealed the mucus produced by Palythoa caribaeorum with biological activities, offering alternative therapies for the treatment of cancer and as a potential antibacterial agent.

Whilst natural analogues for future ocean conditions such as CO2 seeps and enclosed lagoons in coral reef regions have received much recent research attention, most efforts in such locations have focused on the effects of prolonged high CO2 levels on scleractinian corals and fishes. Here, we demonstrate that the three species of zooxanthellate zoantharians, hexacorallian non-calcifying "cousins" of scleractinians, are common across five coral reef natural analogue sites with high CO2 levels in the western Pacific Ocean, in Japan (n = 2), Palau, Papua New Guinea, and New Caledonia (n = 1 each). These current observations support previously reported cases of high Palythoa and Zoanthus abundance and dominance on various impacted coral reefs worldwide. The results demonstrate the need for more research on the ecological roles of zooxanthellate zoantharians in coral reef systems, as well as examining other "understudied" taxa that may become increasingly important in the near future under climate change scenarios. Given their abundance in these sites combined with ease in sampling and non-CITES status, some zoantharian species should make excellent hexacoral models for examining potential resilience or resistance mechanisms of anthozoans to future high pCO2 conditions. [ABSTRACT FROM AUTHOR]

Anemone-like animals belonging to the order Zoantharia are common anthozoans widely distributed from shallow to deep tropical and subtropical waters. Some species are well-known because of their high toxicity due to the presence of palytoxin (PLTX) in their tissues. PLTX is a large polyhydroxylated compound and one of the most potent toxins known. Currently, the PLTX biosynthetic pathway in zoantharians and the role of the host or the putative symbiotic organism(s) involved in this pathway are entirely unknown. To better understand the presence of PLTX in some Zoantharia, twenty-nine zoantharian colonies were analysed in this study. All zoantharian samples and their endosymbiotic dinoflagellates (Symbiodiniaceae = Zooxanthellae) were identified using DNA barcoding and phylogenetic reconstructions. Quantification of PLTX and its analogues showed that the yields contained in Palythoa heliodiscus, Palythoa aff. clavata and one potentially undescribed species of Palythoa are among the highest ever found (up to > 2 mg/g of wet zoantharian). Mass spectrometry imaging was used for the first time on Palythoa samples and revealed that in situ distribution of PLTX is mainly located in ectodermal tissues such as the epidermis of the body wall and the pharynx. Moreover, high levels of PLTX have been detected in histological regions where few or no Symbiodiniaceae cells could be observed. Finally, issues such as host‐specificity and environmental variables driving biogeographical patterns of hosted Symbiodiniaceae in zoantharian lineages were discussed in light of our phylogenetic results as well as the patterns of PLTX distribution. It was concluded that (1) the variability of Symbiodiniaceae diversity may be related to ecological divergence in Zoantharia, (2) all Palythoa species hosted Cladocopium Symbiodiniaceae (formerly clade C), (3) the sole presence of Cladocopium is not sufficient to explain the presence of high concentrations of PLTX and/or its analogues, and (4) the ability to produce high levels of PLTX and/or its analogues highlighted in some Palythoa species could be a plesiomorphic character inherited from their last common ancestor and subsequently lost in several lineages. [ABSTRACT FROM AUTHOR]

Naegleria fowleri is the causative agent the primary amoebic meningoencephalitis (PAM), a fatal disease in more than the 90% of the reported cases that affects the central nervous system. The amoeba infects the nasal cavity of mostly children and young adults who report previous aquatic exposure in warm water sources. The rapid progression of the disease and the lack of effective and safety therapeutic options make the search of new anti-amoebic compounds an urgent issue. In this study, twelve sesquiterpene lactones isolated from the zoanthid Palythoa aff. clavata were tested against the trophozoite stage of Naegleria fowleri. Anhydroartemorin (2) and 1(10)Z,4E,14-acetoxy-costunolide (3) showed the best anti-amoeboid activity values with IC50 23.02 ± 1.26 and 28.34 ± 6.27, respectively. In addition, the mechanisms of programmed cell death induction of these two molecules were evaluated with positive results for both compounds. Finally, a structure-activity relationship was analyzed to reveal the dependence of reactivity and lipophilicity on the biological activity. The log P values of the compounds were calculated to postulate them as good candidates to cross the blood-brain barrier, a limiting factor in the development of new anti-Naegleria treatments. Therefore, the mentioned sesquiterpene lactones could be considered as potential PAM therapeutic options in the future.

The impact of invasive species has been increasing in recent decades due to globalization, threatening marine biodiversity. Tubastraea spp. (sun corals) have been spreading worldwide, showing rapid increases in abundance and/or spatial occupancy and adverse effects on recipient native ecosystems. In Brazil, they have become major invaders, extending discontinuously for more than 3000 km along the coast. Despite increased research efforts on sun coral ecology/biology over the last decade, information about the species' environmental tolerance and interactions with native species is still scarce. In this context, temperature may be an important driver, as it affects species interactions, primarily through its influence on organismal physiology. Thus, in the present study we assessed the effects of temperature in the invasive T. coccinea and the native zoanthid Palythoa caribaeorum, as well as on their interactions, via a 3-week mesocosm experiment, exposing the species (individually and grafted together) to a temperature range of 16–31 °C. This was accompanied by measuring key physiological traits (metabolism, growth, feeding rates and competitive behavior) that underlie species performance, and hence, competitive strength. The results showed that at Arvoredo Island, Brazil, currently the southern distribution limit of both species, (1) T. coccinea exhibited limited capacity to adjust to sudden temperature changes, (2) T. coccinea's physical attacks did not affect P. caribaeorum, but induced increased metabolic costs in the former, while triggering increased growth in the latter, leading to eventual overgrowth of the sun coral and (3) that temperature interacted synergistically with the presence of the competitor in both species under high-temperature stress. These findings suggest that T. coccinea's successful invasion is mainly associated with r-selected life-history traits, rather than competitive strength or a high plasticity to temperature changes, and thus, communities with specific native competitors and/or a variable thermal regime may be more resistant to sun coral invasion. [ABSTRACT FROM AUTHOR]

Despite much research on zoantharians, little work has been done on the abundance of these animals in depths greater than 5 m. In this study, we examined the abundance of zoantharian species and their associated fauna at four depths (5, 10, 20, and 30 m) at multiple sites on the leeward west side of Curaçao in the southern Caribbean in order to provide baseline data. We aimed to quantify zoantharian-host associations in Curaçao to examine if the associations present vary according to different sites and across depths. Results showed that zooxanthellate Palythoa and Zoanthus were most common in shallow waters (5 m), although perhaps less common than observed 35-45 years ago, while sponge-associated species of Macrocnemina were commonly observed at greater depths. There was increasing zoantharian abundance and diversity with greater depth, and two major clusters of zoantharian assemblages in multi-dimensional scaling analyses, one cluster of shallow 5-m datasets, and the other of the large majority of 10-, 20-, and 30-m datasets, demonstrating that assemblages differed significantly by depth (5 m vs. 10, 20, 30 m). In contrast, no significant differences in zoantharian abundance or assemblage were seen across different sites. The data from this study establish a baseline of zoantharian assemblage data that can be compared with other regions and to datasets from Curaçao in the future, which will be of importance in tracking ecological shifts in the face of on-going climate change. [ABSTRACT FROM AUTHOR]

Palythoa caribaeorum is a very common colonial zoanthid in the coastal reefs of Brazil. It is known for its massive production of mucus, which is traditionally used in folk medicine by fishermen in northeastern Brazil. This study identified biologically active compounds in P. caribaerum mucus. Crude mucus was collected during low tides by the manual scraping of colonies; samples were maintained in an ice bath, homogenized, and centrifuged at 16,000  g for 1 h at 4 °C; the supernatant (mucus) was kept at −80 °C until use. The enzymatic (proteolytic and phospholipase A 2 ), inhibitory (metallo, cysteine and serine proteases), and hemagglutinating (human erythrocyte) activities were determined. The results showed high levels of cysteine and metallo proteases, intermediate levels of phosholipase A 2 , low levels of trypsin, and no elastase and chymotrypsin like activities. The mucus showed potent inhibitory activity on snake venom metalloproteases and cysteine proteinase papain. In addition, it showed agglutinating activity towards O + , B + , and A + erythrocyte types. The hemostatic results showed that the mucus prolongs the aPTT and PT, and strongly inhibited platelet aggregation induced by arachidonic acid, collagen, epinephrine, ADP, and thrombin. The antimicrobial activity was tested on 15 strains of bacteria and fungi through the radial diffusion assay in agar, and no activity was observed. Compounds in P. caribaeorum mucus were analyzed for the first time in this study, and our results show potential pharmacological activities in these compounds, which are relevant for use in physiopathological investigations. However, the demonstration of these activities indicates caution in the use of crude mucus in folk medicine. Furthermore, the present or absent activities identified in this mucus suggest that the studied P. caribaeorum colonies were in thermal stress conditions at the time of sample collection; these conditions may precede the bleaching process in zoanthids. Hence, the use of mucus as an indicator of this process should be evaluated in the future. [ABSTRACT FROM AUTHOR]

This is the first report on the Zoantharia fauna (Cnidaria: Hexacorallia) of the isolated oceanic island of Ascension, southern Atlantic, where zoantharians are a dominant component of the shallow-water benthos. Specimens from two expeditions (1983, 2012) were examined regarding external morphology and molecular phylogeny using three DNA markers, which confirmed the presence of four zoantharian species: Palythoa caribaeorum; Palythoa aff. clavata; Parazoanthus swiftii; and Zoanthus sp. Two of these, Palythoa aff. clavata and Parazoanthus swiftii, were previously only known from the western Atlantic and Caribbean. Molecular examination of the zooxanthellae (=Symbiodinium spp.) of Palythoa specimens showed that they were in association with only one type, subclade C1. [ABSTRACT FROM AUTHOR]

Palytoxin (PTX) is a potent marine toxin that was originally found in soft corals from tropical areas of the Pacific Ocean. Soon after, its occurrence was observed in numerous other marine organisms from the same ecological region. More recently, several analogs of PTX were discovered, remarkably all from species of the dinoflagellate genus Ostreopsis. Since these dinoflagellates are also found in other tropical and even in temperate regions, the formerly unsuspected broad distribution of these toxins was revealed. Toxicological studies with these compounds shows repeatedly low LD50 values in different mammals, revealing an acute toxic effect on several organs, as demonstrated by different routes of exposure. Bioassays tested for some marine invertebrates and evidences from environmental populations exposed to the toxins also give indications of the high impact that these compounds may have on natural food webs. The recognition of its wide distribution coupled with the poisoning effects that these toxins can have on animals and especially on humans have concerned the scientific community. In this paper, we review the current knowledge on the effects of PTX and its analogs on different organisms, exposing the impact that these toxins may have in coastal ecosystems.

Zoantharians are one of the least studied orders of benthic cnidarians of the Persian Gulf. A survey and molecular analysis was conducted to determine zoantharian species diversity in the Persian Gulf. For this purpose, 63 colonies of zoantharians were collected from Hengam and Larak Islands in the Strait of Hormuz and some morphological characteristics of each specimen were recorded, i.e. sand encrustation, polyp shape and colour, oral groove, oral zone and oral disc colours as well as tentacle number and colour. After DNA extraction, mitochondrial 16S ribosomal DNA (16S rDNA) and cytochrome oxidase subunit I (COI) were amplified by polymerase chain reaction (PCR). Based on obtained 16S rDNA and COI gene sequences, five putative species-level clades were identified: Zoanthus sansibaricus (N = 30), Palythoa tuberculosa (N = 12), Palythoa mutuki (N = 2), Palythoa aff. mutuki (N = 18) and Neozoanthus sp. Iran (N = 1). While the first three are known species, the last two were potentially novel undescribed species. Palythoa aff. mutuki has an external appearance similar to Palythoa mutuki. However, mitochondrial DNA sequences obtained from these specimens placed them in a previously undescribed species group. The Neozoanthus specimen was morphologically and molecularly different from other described Neozoanthus species. This is the first record of this genus from the Persian Gulf and neighbouring areas. Since there is not much work on zoantharians identification in the Persian Gulf, further sampling and investigation is needed to speculate on the accuracy of these potentially new species and to complete the knowledge of zoantharian diversity in this area. [ABSTRACT FROM PUBLISHER]

Palytoxin (PLTX), one the most potent marine toxins, and/or its analogs, have been identified in different marine organisms, such as Palythoa soft corals, Ostreopsis dinoflagellates, and Trichodesmium cyanobacteria. Although the main concern for human health is PLTXs entrance in the human food chain, there is growing evidence of adverse effects associated with inhalational, cutaneous, and/or ocular exposure to aquarium soft corals contaminated by PLTXs or aquaria waters. Indeed, the number of case reports describing human poisonings after handling these cnidarians is continuously increasing. In general, the signs and symptoms involvemainly the respiratory (rhinorrhea and coughing), skeletomuscular (myalgia, weakness, spasms), cardiovascular (electrocardiogram alterations), gastrointestinal (nausea), and nervous (paresthesia, ataxia, tremors) systems or apparates. The widespread phenomenon, the entity of the signs and symptoms of poisoning and the lack of control in the trade of corals as aquaria decorative elements led to consider these poisonings an emerging sanitary problem. This review summarizes literature data on human poisonings due to, or ascribed to, PLTX-containing soft corals, focusing on the different PLTX congeners identified in these organisms and their toxic potential. [ABSTRACT FROM AUTHOR]

This study is the first review of Zoantharia species in the South China Sea and Gulf of Thailand. In addition to past literature records, new field observations are added from previously unexamined countries and regions. In total 16 species are listed, 15 of which belong to suborder Brachycnemina, and only one to suborder Macrocnemina. Two species are undescribed. The lack of Macrocnemina species is not likely indicative of a low diversity of this suborder in the South China Sea and Gulf of Thailand, but instead of an absence of research below shallow subtidal depths. As the majority of the new records from this study were randomly compiled by researchers who are not experts of Zoantharia, specific surveys by experts are needed in these two marine regions. The present list should provide a solid basis for such future research. [ABSTRACT FROM AUTHOR]

The reproductive biology of Palythoa caribaeorum (Duchassaing & Michelotti 1860) and Protopalythoa variabilis (Duerden 1898) was studied through monthly samples from tagged colonies from June 1996 to June 1997, in São Sebastião channel, São Paulo, Brazil (45º26'W, 23º50'S). The gametogenesis was similar to that of other zoanthids as shown by histological preparations. Oocyte diameters and maturation stages of testis vesicles were evaluated on squash preparations. Both species showed sequential protogynic hermaphroditism, with high frequency of fertile polyps (83% in P. variabilis and 72% in P. caribaeorum), high frequency of colonies in female sex condition (65.3% of P. variabilis and 41.7% of P. caribaeorum), and apparently continuous gametogenesis. In P. caribaeorum, egg release was continuous and sperm release took place during half of the analyzed period. In P. variabilis, egg and sperm release occurred in April-May and February-March 1997, respectively.A biologia reprodutiva de Palythoa caribaeorum (Duchassaing & Michelotti 1860) e Protopalythoa variabilis (Duerden 1898) foi estudada por amostras mensais de colônias etiquetadas de junho de 1996 a junho de 1997, no canal de São Sebastião, São Paulo, Brasil (45º26'W, 23º50'S). A gametogênese apresentou-se semelhante à de outros zoantídeos, como evidenciado em preparações histológicas. O diâmetro dos oócitos e os estágios de maturação dos folículos testiculares foram avaliados por preparações do tipo "squash". Ambas as espécies mostraram hermafroditismo seqüencial protogínico, com alta freqüência de pólipos férteis (83% em P. variabilis e 72% em P. caribaeorum) e de colônias na condição sexual feminina (65,3% para P. variabilis e 41,7% para P. caribaeorum), e, aparentemente, gametogênese contínua. Em P. caribaeorum, a liberação de oócitos foi contínua e a liberação de espermatozóides ocorreu durante metade do período analisado. Para P. variabilis, a liberação de oócitos e de espermatozóides ocorreu em abril-maio e fevereiro-março de 1997, respectivamente.

The purpose of this application, made under Article 23.9.3 of the Code, is to conserve the family-group name Sphenopidae Hertwig, 1882 that is in widespread and current usage for a group that includes ecologically, medically and toxicologically important species. Sphenopidae Hertwig, 1882 is threatened by Palythoidae Duchassaing de Fombressin & Michelotti, 1860, which has only been used once as a valid name since 1899. [ABSTRACT FROM AUTHOR]

Palytoxin (PLTX), one the most potent marine toxins, and/or its analogs, have been identified in different marine organisms, such as Palythoa soft corals, Ostreopsis dinoflagellates, and Trichodesmium cyanobacteria. Although the main concern for human health is PLTXs entrance in the human food chain, there is growing evidence of adverse effects associated with inhalational, cutaneous, and/or ocular exposure to aquarium soft corals contaminated by PLTXs or aquaria waters. Indeed, the number of case reports describing human poisonings after handling these cnidarians is continuously increasing. In general, the signs and symptoms involve mainly the respiratory (rhinorrhea and coughing), skeletomuscular (myalgia, weakness, spasms), cardiovascular (electrocardiogram alterations), gastrointestinal (nausea), and nervous (paresthesia, ataxia, tremors) systems or apparates. The widespread phenomenon, the entity of the signs and symptoms of poisoning and the lack of control in the trade of corals as aquaria decorative elements led to consider these poisonings an emerging sanitary problem. This review summarizes literature data on human poisonings due to, or ascribed to, PLTX-containing soft corals, focusing on the different PLTX congeners identified in these organisms and their toxic potential.

The Persian Gulf, a semi-enclosed sea in the subtropical northwest of the Indian Ocean, is noted for its unique biodiversity under its extreme ecological conditions. Despite high biodiversity levels, many groups of marine invertebrates in this area have remained uninvestigated. The order Zoantharia (zoanthids) is one of these taxonomically neglected groups. In this study, diversity of shallow water zoanthids off the Qeshm Island, the largest island in the Persian Gulf, was investigated for the first time. Using in situ field examination integrated with 16S rDNA sequencing and phylogenetic analysis, the presence of three zoanthid species in the inter-tidal and shallow water zone of Qeshm Island were demonstrated: Zoanthus sansibaricus (n = 12) with five morphotypes, Palythoa cf. mutuki (n = 10) with two morphotypes and Palythoa tuberculosa (n = 4) with just one morphotype. In addition to species identification, molecular examination determined phylogenetic relationships of specimens with other previously reported zoanthid species. While Zoanthus sansibaricus and Palythoa tuberculosa are two known zoanthid species, based on molecular data, Palythoa cf. mutuki is potentially a novel undescribed species. However, due to lack of data on zoanthid research and distribution for the entire Persian Gulf, further investigation is needed to clearly ascertain this matter. [ABSTRACT FROM AUTHOR]

Naegleria fowleri is the causative agent the primary amoebic meningoencephalitis (PAM), a fatal disease in more than the 90% of the reported cases that affects the central nervous system. The amoeba infects the nasal cavity of mostly children and young adults who report previous aquatic exposure in warm water sources. The rapid progression of the disease and the lack of effective and safety therapeutic options make the search of new anti-amoebic compounds an urgent issue. In this study, twelve sesquiterpene lactones isolated from the zoanthid Palythoa aff. clavata were tested against the trophozoite stage of Naegleria fowleri. Anhydroartemorin (2) and 1(10) Z ,4 E ,14-acetoxy-costunolide (3) showed the best anti-amoeboid activity values with IC 50 23.02 ± 1.26 and 28.34 ± 6.27, respectively. In addition, the mechanisms of programmed cell death induction of these two molecules were evaluated with positive results for both compounds. Finally, a structure-activity relationship was analyzed to reveal the dependence of reactivity and lipophilicity on the biological activity. The log P values of the compounds were calculated to postulate them as good candidates to cross the blood-brain barrier, a limiting factor in the development of new anti- Naegleria treatments. Therefore, the mentioned sesquiterpene lactones could be considered as potential PAM therapeutic options in the future. [Display omitted] • Three germacrane sesquiterpene lactones showed anti- Naegleria activity. • Anhydroartemorin was the most active molecule with an IC 50 of 23.02 μM. • Anhydroartemorin and cis-trans -Costunolide-14-acetate induce PCD in treated amoebae. [ABSTRACT FROM AUTHOR]

The Ogasawara (Bonin) Islands are oceanic islands approximately 1000 km south of mainland Japan noted for their high levels of both terrestrial and marine endemicity. Despite their unique location, the marine fauna of many taxa remains relatively under-examined. In this study, we specifically investigated the diversity of shallow water zoanthids (Cnidaria: Anthozoa: Hexacorallia) and their symbiotic zooxanthellae (Symbiodinium spp.) of the Ogasawara Islands for the first time. Using in situ field examinations combined with DNA sequencing and phylogenetic analyses, our results show the presence of five zoanthid species in the Ogasawara Islands; Zoanthus sansibaricus, Z. kuroshio, Palythoa tuberculosa, P. mutuki, and one potentially undescribed species of Palythoa. While most collected specimens were in symbiosis with clade C Symbiodinium as seen in southern Japan and other Indo-Pacific locations, one specimen of Z. kuroshio was unexpectedly in symbiosis with clade A, and no Z. sansibaricus colonies contained specific C1z type zooxanthellae previously observed at other locations. Overall, the Ogasawara Islands showed a lower zooxanthellate zoanthid species diversity (n = 5) than the non-oceanic Okinawa Islands (n > 10), which are at roughly the same latitude. Instead, the islands' relatively depauperate zoanthid/symbiont fauna more closely resembles that of the northern Izu Islands. [ABSTRACT FROM AUTHOR]

Abstract: A series of case reports and anecdotal references describe the adverse effects on human health ascribed to the marine toxin palytoxin (PLTX) after different exposure routes. They include poisonings after oral intake of contaminated seafood, but also inhalation and cutaneous/systemic exposures after direct contact with aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing cnidarian zoanthids. The symptoms commonly recorded during PLTX intoxication are general malaise and weakness, associated with myalgia, respiratory effects, impairment of the neuromuscular apparatus and abnormalities in cardiac function. Systemic symptoms are often recorded together with local damages whose intensity varies according to the route and length of exposure. Gastrointestinal malaise or respiratory distress is common for oral and inhalational exposure, respectively. In addition, irritant properties of PLTX probably account for the inflammatory reactions typical of cutaneous and inhalational contact. Unfortunately, the toxin identification and/or quantification are often incomplete or missing and cases of poisoning are indirectly ascribed to PLTXs, according only to symptoms, anamnesis and environmental/epidemiological investigations (i.e. zoanthid handling or ingestion of particular seafood). Based on the available literature, we suggest a “case definition of PLTX poisonings” according to the main exposure routes, and, we propose the main symptoms to be checked, as well as, hemato-clinical analysis to be carried out. We also suggest the performance of specific analyses both on biological specimens of patients, as well as, on the contaminated materials responsible for the poisoning. A standardized protocol for data collection could provide a more rapid and reliable diagnosis of palytoxin-poisoning, but also the collection of necessary data for the risk assessment for this family of toxins. [Copyright &y& Elsevier]

Palytoxin (PTX) is a potent marine toxin that was originally found in soft corals from tropical areas of the Pacific Ocean. Soon after, its occurrence was observed in numerous other marine organisms from the same ecological region. More recently, several analogs of PTX were discovered, remarkably all from species of the dinoflagellate genus Ostreopsis. Since these dinoflagellates are also found in other tropical and even in temperate regions, the formerly unsuspected broad distribution of these toxins was revealed. Toxicological studies with these compounds shows repeatedly low LD50 values in different mammals, revealing an acute toxic effect on several organs, as demonstrated by different routes of exposure. Bioassays tested for some marine invertebrates and evidences from environmental populations exposed to the toxins also give indications of the high impact that these compounds may have on natural food webs. The recognition of its wide distribution coupled with the poisoning effects that these toxins can have on animals and especially on humans have concerned the scientific community. In this paper, we review the current knowledge on the effects of PTX and its analogs on different organisms, exposing the impact that these toxins may have in coastal ecosystems. [ABSTRACT FROM AUTHOR]

In the Southwestern Atlantic reefs (SWA), some species of massive scleractinians and zoantharians are adapted to turbid waters, periodic desiccation, and sediment resuspension events. Moreover, phase shifts in this region have mostly been characterized by the emergence of algae and, less typically, zoantharians. However, nutrient excess and organic pollution are key drivers of the hard coral habitat degradation and may, thus, favor the emergence of novel zoantharian-dominated habitats. Many zoantharian species, particularly those from the genera Palythoa and Zoanthus , have traits that could help them thrive under conditions detrimental to reef-building corals, including rapid growth, several asexual reproduction strategies, high morphological plasticity, and generalist nutrient acquisition strategies. Thus, in a near future, stress-tolerant zoantharians may thrive in nutrient-enriched subtidal SWA locations under low heat stress, such as, upwelling. Overall, coral-zoantharian phase shifts in the SWA may decrease the species richness of reef communities, ultimately influencing ecosystem functioning and services, such as the provision of nursery habitats, fish biomass production, and coastline protection. However, zoantharians will also be threatened at intertidal zones, which are expected to experience higher heat stress, solar radiation, and sea-level rise. Although zoantharians appear to cope well with some local stressors (e.g., decreasing water quality), they are vulnerable to climate change (e.g., heatwaves), invasive species (Tubastraea spp.), microplastics, diseases, and mostly restricted to a narrow depth range (0–15 m depth) in SWA reefs. This shallow zone is particularly affected by climate change, compressing the three-dimensional habitat and limiting depth refugia in deeper SWA reefs. As mesophotic ecosystems have been hypothesized as short-term refuges to disturbances for some species, the narrow depth limit of zoantharians seems to be a potential factor that might increase their vulnerability to growing climate change pressures in SWA shallow-water reefs. Together, these could lead to both range expansions in some locations and loss of suitable reef habitats in other sites. Additional research is needed to better understand the systemic responses of these novel SWA reefs to the concert of increasing and interactive local and global stressors, and their implications for ecosystem functioning and service provisions. [Display omitted] • Local impacts promote the emergence of novel zoantharian-dominated habitats. • Zoantharians are vulnerable to climate change, microplastics, invasive species, and diseases. • Traits such as rapid growth, the ability to cope with nutrient enrichment, and reproduction strategies allow their emergence. • Traits such as high morphological plasticity and a generalist trophic ecology allow their persistence. • Short-term impacts may promote phase shifts but long-term global stressors may threaten them. [ABSTRACT FROM AUTHOR]

Previous phylogenetic studies based on mitochondrial DNA markers have suggested that the zoanthid genus Palythoa may consist of both Palythoa species (Palythoa tuberculosa) and species formerly assigned to the genus Protopalythoa (Palythoa mutuki, Palythoa heliodiscus). In the present study various Palythoa spp. samples collected primarily from southern Japan with additional samples from the Indo-Pacific and Caribbean Sea were examined. The nuclear internal transcribed spacer of ribosomal DNA (ITS-rDNA) was sequenced and aligned for phylogenetic analyses to further investigate the relationship between P. tuberculosa, P. mutuki, and P. heliodiscus. ITSrDNA analyses showed species groups forming monophylies with similar topology but with much higher resolution than seen for mitochondrial phylogenetic analyses. The results also confirmed the very close relationship of P. tuberculosa and P. mutuki. Some specimens appeared to be a potentially undescribed Palythoa species (designated Palythoa sp. sakurajimensis). Additionally, ITS-rDNA sequences of P. mutuki and P. tuberculosa showed additive polymorphic site, demonstrating for the first time a potential history of reticulate evolution in Palythoa. [ABSTRACT FROM AUTHOR]

The International Commission on Zoological Nomenclature has conserved the usage of the family-group name SphenopidaeHertwig, 1882 for a group of brachyneminic zoantharians over its rarely-used senior subjective synonym Palythoidae Duchassaing de Fombressin & Michelotti, 1860. [ABSTRACT FROM AUTHOR]

In Japan, zooxanthellate Palythoa tuberculosa Klunzinger and Palythoa mutuki Verrill (Anthozoa: Hexacorallia: Zoantharia) are found over a 1,000 + km latitudinal range, often in environments where most other zooxanthellate anthozoans are not found (i.e. tidal lagoon pools, around shallow water hydrothermal vents, subtropical rocky shorelines). Sequences of internal transcribed spacer of ribosomal DNA (ITS-rDNA) of the symbiotic dinoflagellate genus Symbiodinium (zooxanthellae) Freudenthal (Order Suessiales) from P. tuberculosa and P. mutuki from several locations in Japan (34° 11'N-24° 16'N) were analysed. Unexpectedly, despite the ability of the genus Palythoa to be flexible in association with different Symbiodinium subclades, most (35 of 36) Palythoa investigated here specifically associate with subclade Cl and closely related types. Symbiodinium subclade Cl has been characterized as a "generalist" in terms of the ability to associate with a range of hosts, but present results suggest that subclade Cl may also be a "generalist" in terms of being able to live in a variety of environments over a latitudinal range. [ABSTRACT FROM AUTHOR]

Seven different types of nematocyst are detailed and illustrated from the Zoanthidea. We studied the size population structure of nematocyst capsules: how they are affected by preservation, and how and what should be measured. Populations of two types, large holotrichs andp-mastigophores, from the mesenterial filaments ofProtopalythoa heliodiscusandPr. mutukihave been compared using length, width, and (forp-mastigophores) shaft length. The analysis employed bivariate scattergrams and discriminant analysis. The two species are strongly differentiated by their holotrichs, less well by theirp-mastigophores. The problem of bimodal size distributions is considered and resolved. It is recommended that nematocyst capsule population descriptors should always be included in species’ descriptions, in addition to or instead of the customary minimum-maximum range. [ABSTRACT FROM AUTHOR]