RESUMO
Success and impact metrics in science are based on a system that perpetuates sexist and racist "rewards" by prioritizing citations and impact factors. These metrics are flawed and biased against already marginalized groups and fail to accurately capture the breadth of individuals' meaningful scientific impacts. We advocate shifting this outdated value system to advance science through principles of justice, equity, diversity, and inclusion. We outline pathways for a paradigm shift in scientific values based on multidimensional mentorship and promoting mentee well-being. These actions will require collective efforts supported by academic leaders and administrators to drive essential systemic change.
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Recompensa , Ciência , Viés , Diversidade Cultural , Humanos , TutoriaRESUMO
Coral reefs are under threat from disease as climate change alters environmental conditions. Rising temperatures exacerbate coral disease, but this relationship is likely complex as other factors also influence coral disease prevalence. To better understand this relationship, we meta-analytically examined 108 studies for changes in global coral disease over time alongside temperature, expressed using average summer sea surface temperature (SST) and cumulative heat stress as weekly sea surface temperature anomalies (WSSTAs). We found that both rising average summer SST and WSSTA were associated with global increases in the mean and variability in coral disease prevalence. Global coral disease prevalence tripled, reaching 9.92% in the 25 years examined, and the effect of 'year' became more stable (i.e. prevalence has lower variance over time), contrasting the effects of the two temperature stressors. Regional patterns diverged over time and differed in response to average summer SST. Our model predicted that, under the same trajectory, 76.8% of corals would be diseased globally by 2100, even assuming moderate average summer SST and WSSTA. These results highlight the need for urgent action to mitigate coral disease. Mitigating the impact of rising ocean temperatures on coral disease is a complex challenge requiring global discussion and further study.
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Antozoários , Animais , Antozoários/fisiologia , Temperatura , Prevalência , Recifes de Corais , Mudança ClimáticaRESUMO
Coral bleaching has impacted reefs worldwide and the predictions of near-annual bleaching from over two decades ago have now been realized. While technology currently provides the means to predict large-scale bleaching, predicting reef-scale and within-reef patterns in real-time for all reef users is limited. In 2020, heat stress across the Great Barrier Reef underpinned the region's third bleaching event in 5 years. Here we review the heterogeneous emergence of bleaching across Heron Island reef habitats and discuss the oceanographic drivers that underpinned variable bleaching emergence. We do so as a case study to highlight how reef end-user groups who engage with coral reefs in different ways require targeted guidance for how, and when, to alter their use of coral reefs in response to bleaching events. Our case study of coral bleaching emergence demonstrates how within-reef scale nowcasting of coral bleaching could aid the development of accessible and equitable bleaching response strategies on coral reefs. Also see the video abstract here: https://youtu.be/N9Tgb8N-vN0.
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Antozoários , Recifes de Corais , Animais , Mudança Climática , Ecossistema , Resposta ao Choque TérmicoRESUMO
Coral bleaching has increasingly impacted reefs worldwide over the past four decades. Despite almost 40 years of research into the mechanistic, physiological, ecological, biophysical and climatic drivers of coral bleaching, metrics to allow comparison between ecological observations and experimental simulations still do not exist. Here we describe a novel metric - experimental Degree Heating Week (eDHW) - with which to standardise the persistently variable thermal conditions employed across experimental studies of coral bleaching by modify the widely used Degree Heating Week (DHW) metric used in ecological studies to standardise cumulative heat loading.
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Antozoários , Temperatura Alta , Animais , Recifes de CoraisRESUMO
Globally, collapse of ecosystems-potentially irreversible change to ecosystem structure, composition and function-imperils biodiversity, human health and well-being. We examine the current state and recent trajectories of 19 ecosystems, spanning 58° of latitude across 7.7 M km2 , from Australia's coral reefs to terrestrial Antarctica. Pressures from global climate change and regional human impacts, occurring as chronic 'presses' and/or acute 'pulses', drive ecosystem collapse. Ecosystem responses to 5-17 pressures were categorised as four collapse profiles-abrupt, smooth, stepped and fluctuating. The manifestation of widespread ecosystem collapse is a stark warning of the necessity to take action. We present a three-step assessment and management framework (3As Pathway Awareness, Anticipation and Action) to aid strategic and effective mitigation to alleviate further degradation to help secure our future.
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Recifes de Corais , Ecossistema , Regiões Antárticas , Biodiversidade , Mudança Climática , HumanosRESUMO
If we are to ensure the persistence of species in an increasingly warm world, of interest is the identification of drivers that affect the ability of an organism to resist thermal stress. Underpinning any organism's capacity for resistance is a complex interplay between biological and physical factors occurring over multiple scales. Tropical coral reefs are a unique system, in that their function is dependent upon the maintenance of a coral-algal symbiosis that is directly disrupted by increases in water temperature. A number of physical factors have been identified as affecting the biological responses of the coral organism under broadscale thermal anomalies. One such factor is water flow, which is capable of modulating both organismal metabolic functioning and thermal environments. Understanding the physiological and hydrodynamic drivers of organism response to thermal stress improves predictive capabilities and informs targeted management responses, thereby increasing the resilience of reefs into the future.
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Antozoários/fisiologia , Recifes de Corais , Aquecimento Global , Hidrodinâmica , Estresse Fisiológico/fisiologia , Animais , Clima , Temperatura Alta , Oceanos e Mares , Simbiose/fisiologiaRESUMO
Extreme heat wave events are now causing ecosystem degradation across marine ecosystems. The consequences of this heat-induced damage range from the rapid loss of habitat-forming organisms, through to a reduction in the services that ecosystems support, and ultimately to impacts on human health and society. How we tackle the sudden emergence of ecosystem-wide degradation has not yet been addressed in the context of marine heat waves. An examination of recent marine heat waves from around Australia points to the potential important role that respite or refuge from environmental extremes can play in enabling organismal survival. However, most ecological interventions are being devised with a target of mid to late-century implementation, at which time many of the ecosystems, that the interventions are targeted towards, will have already undergone repeated and widespread heat wave induced degradation. Here, our assessment of the merits of proposed ecological interventions, across a spectrum of approaches, to counter marine environmental extremes, reveals a lack preparedness to counter the effects of extreme conditions on marine ecosystems. The ecological influence of these extremes are projected to continue to impact marine ecosystems in the coming years, long before these interventions can be developed. Our assessment reveals that approaches which are technologically ready and likely to be socially acceptable are locally deployable only, whereas those which are scalable-for example to features as large as major reef systems-are not close to being testable, and are unlikely to obtain social licence for deployment. Knowledge of the environmental timescales for survival of extremes, via respite or refuge, inferred from field observations will help test such intervention tools. The growing frequency of extreme events such as marine heat waves increases the urgency to consider mitigation and intervention tools that support organismal and ecosystem survival in the immediate future, while global climate mitigation and/or intervention are formulated.
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Mudança Climática , Ecossistema , Austrália , Clima , Temperatura Alta , HumanosRESUMO
Increasing physical damage on coral reefs from predation, storms and anthropogenic disturbances highlights the need to understand the impact of injury on the coral immune system. In this study, we examined the regulation of the coral immune response over 10 days following physical trauma artificially inflicted on in situ colonies of the coral Acropora aspera, simultaneously with bacterial colonization of the lesions. Corals responded to injury by increasing the expression of immune system-related genes involved in the Toll-like and NOD-like receptor signalling pathways and the lectin-complement system in three phases (<2, 4 and 10 days post-injury). Phenoloxidase activity was also significantly upregulated in two phases (<3 and 10 days post-injury), as were levels of non-fluorescent chromoprotein. In addition, green fluorescent protein expression was upregulated in response to injury from 4 days post-injury, while cyan fluorescent protein expression was reduced. No shifts in the composition of coral-associated bacterial communities were evident following injury based on 16S rRNA gene amplicon pyrosequencing. Bacteria-specific fluorescence in situ hybridization also showed no evidence of bacterial colonization of the wound or regenerating tissues. Coral tissues showed near-complete regeneration of lesions within 10 days. This study demonstrates that corals exhibit immune responses that support rapid recovery following physical injury, maintain coral microbial homeostasis and prevent bacterial infestation that may compromise coral fitness.
Assuntos
Antozoários/imunologia , Antozoários/microbiologia , Bactérias/patogenicidade , Regeneração , Animais , Bactérias/isolamento & purificação , Imunidade Inata , Proteínas Adaptadoras de Sinalização NOD/genética , Transdução de Sinais , Receptores Toll-Like/genéticaRESUMO
Microbial community structure on coral reefs is strongly influenced by coral-algae interactions; however, the extent to which this influence is mediated by fishes is unknown. By excluding fleshy macroalgae, cultivating palatable filamentous algae and engaging in frequent aggression to protect resources, territorial damselfish (f. Pomacentridae), such as Stegastes, mediate macro-benthic dynamics on coral reefs and may significantly influence microbial communities. To elucidate how Stegastes apicalis and Stegastes nigricans may alter benthic microbial assemblages and coral health, we determined the benthic community composition (epilithic algal matrix and prokaryotes) and coral disease prevalence inside and outside of damselfish territories in the Great Barrier Reef, Australia. 16S rDNA sequencing revealed distinct bacterial communities associated with turf algae and a two to three times greater relative abundance of phylotypes with high sequence similarity to potential coral pathogens inside Stegastes's territories. These potentially pathogenic phylotypes (totalling 30.04% of the community) were found to have high sequence similarity to those amplified from black band disease (BBD) and disease affected corals worldwide. Disease surveys further revealed a significantly higher occurrence of BBD inside S. nigricans's territories. These findings demonstrate the first link between fish behaviour, reservoirs of potential coral disease pathogens and the prevalence of coral disease.
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Antozoários/microbiologia , Fenômenos Fisiológicos Bacterianos , Perciformes/fisiologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Sequência de Bases , Recifes de Corais , DNA Bacteriano/genética , Comportamento Alimentar , Dados de Sequência Molecular , Filogenia , Queensland , RNA Ribossômico 16S/genética , Alga Marinha/crescimento & desenvolvimento , Alinhamento de SequênciaRESUMO
Deep sea benthic habitats are low productivity ecosystems that host an abundance of organisms within the Cnidaria phylum. The technical limitations and the high cost of deep sea surveys have made exploring deep sea environments and the biology of the organisms that inhabit them challenging. In spite of the widespread recognition of Cnidaria's environmental importance in these ecosystems, the microbial assemblage and its role in coral functioning have only been studied for a few deep water corals. Here, we explored the microbial diversity of deep sea corals by recovering nucleic acids from museum archive specimens. Firstly, we amplified and sequenced the V1-V3 regions of the 16S rRNA gene of these specimens, then we utilized the generated sequences to shed light on the microbial diversity associated with seven families of corals collected from depth in the Coral Sea (depth range 1309 to 2959 m) and Southern Ocean (depth range 1401 to 2071 m) benthic habitats. Surprisingly, Cyanobacteria sequences were consistently associated with six out of seven coral families from both sampling locations, suggesting that these bacteria are potentially ubiquitous members of the microbiome within these cold and deep sea water corals. Additionally, we show that Cnidaria might benefit from symbiotic associations with a range of chemosynthetic bacteria including nitrite, carbon monoxide and sulfur oxidizers. Consistent with previous studies, we show that sequences associated with the bacterial phyla Proteobacteria, Verrucomicrobia, Planctomycetes and Acidobacteriota dominated the microbial community of corals in the deep sea. We also explored genomes of the bacterial genus Mycoplasma, which we identified as associated with specimens of three deep sea coral families, finding evidence that these bacteria may aid the host immune system. Importantly our results show that museum specimens retain components of host microbiome that can provide new insights into the diversity of deep sea coral microbiomes (and potentially other organisms), as well as the diversity of microbes writ large in deep sea ecosystems.
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BACKGROUND: As a step towards understanding coral immunity we present the first whole transcriptome analysis of the acute responses of Acropora millepora to challenge with the bacterial cell wall derivative MDP and the viral mimic poly I:C, defined immunogens provoking distinct but well characterised responses in higher animals. RESULTS: These experiments reveal similarities with the responses both of arthropods and mammals, as well as coral-specific effects. The most surprising finding was that MDP specifically induced three members of the GiMAP gene family, which has been implicated in immunity in mammals but is absent from Drosophila and Caenorhabditis. Like their mammalian homologs, GiMAP genes are arranged in a tandem cluster in the coral genome. CONCLUSIONS: A phylogenomic survey of this gene family implies ancient origins, multiple independent losses and lineage-specific expansions during animal evolution. Whilst functional convergence cannot be ruled out, GiMAP expression in corals may reflect an ancestral role in immunity, perhaps in phagolysosomal processing.
Assuntos
Antozoários/genética , Antozoários/imunologia , GTP Fosfo-Hidrolases/genética , Regulação Enzimológica da Expressão Gênica/imunologia , Imunidade Inata/genética , Plantas/imunologia , Transcrição Gênica/imunologia , Acetilmuramil-Alanil-Isoglutamina/imunologia , Sequência de Aminoácidos , Animais , Antozoários/enzimologia , Parede Celular/imunologia , Parede Celular/metabolismo , GTP Fosfo-Hidrolases/química , GTP Fosfo-Hidrolases/metabolismo , Perfilação da Expressão Gênica , Humanos , Mamíferos/imunologia , Dados de Sequência Molecular , Poli I-C/imunologia , Estrutura Terciária de Proteína , Pseudomonas/citologia , Regulação para Cima/imunologiaRESUMO
Outbreaks of coral disease are often associated with global and local stressors like changes in temperature and poor water quality. A severe coral disease outbreak was recorded in the primary reef-building taxa Montipora spp. in a high-latitude lagoon at Norfolk Island following heat stress and pollution events in 2020. Disease signs suggest the occurrence of a Montiporid White Syndrome with four distinct phases and maximum measured tissue loss of 329 mm-2 day-1. In December 2020 and April 2021, 60% of the Montipora community were impacted and disease severity increased by 54% over this period. Spatial patterns in prevalence indicate the disease is associated with exposure to poor water quality in addition to size class of coral colonies. High prevalence levels make this event comparable to some of the most severe coral disease outbreaks recorded to date demonstrating the vulnerability of this system to combined impacts of warming and pollution.
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Globally, coral reefs face increasing disease prevalence and large-scale outbreak events. These outbreaks offer insights into microbial and functional patterns of coral disease, including early indicators of disease that may be present in visually-healthy tissues. Outbreak events also allow investigation of how reef-building corals, typically colonial organisms, respond to disease. We studied Pocillopora damicornis during an acute tissue loss disease outbreak on Guam to determine whether dysbiosis was present in visually-healthy tissues ahead of advancing disease lesions. These data reveal that coral fragments with visual evidence of disease are expectedly dysbiotic with high microbial and metabolomic variability. However, visually-healthy tissues from the same colonies lacked dysbiosis, suggesting disease containment near the affected area. These results challenge the idea of using broad dysbiosis as a pre-visual disease indicator and prompt reevaluation of disease assessment in colonial organisms such as reef-building corals.
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Antozoários , Animais , Disbiose , Recifes de Corais , Metabolômica , GuamRESUMO
One of the most widespread coral diseases linked to anthropogenic activities and recorded on reefs worldwide is characterized by anomalous growth formations in stony corals, referred to as coral growth anomalies (GAs). The biological functions of GA tissue include limited reproduction, reduced access to resources, and weakened ability to defend against predators. Transcriptomic analyses have revealed that, in some cases, disease progression can involve host genes related to oncogenesis, suggesting that the GA tissues may be malignant neoplasms such as those developed by vertebrates. The number of studies reporting the presence of GAs in common reef-forming species highlights the urgency of a thorough understanding of the pathology and causative factors of this disease and its parallels to higher organism malignant tissue growth. Here, we review the current state of knowledge on the etiology and holobiont features of GAs in reef-building corals.
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Antozoários , Neoplasias , Animais , Perfilação da Expressão Gênica , Recifes de CoraisRESUMO
Coral reefs are amongst the most biodiverse ecosystems on earth, and while stony corals create the foundational complexity of these ecosystems, octocorals and anemones contribute significantly to their biodiversity and function. Like stony corals, many octocorals contain Symbiodiniaceae endosymbionts and can bleach when temperatures exceed the species' upper thermal limit. Here, we report octocoral bleaching susceptibility and resistance within the subtropical Lord Howe Island coral reef ecosystem during and after marine heatwaves in 2019. Octocoral and anemone surveys were conducted at multiple reef locations within the Lord Howe Island lagoon during, immediately after, and 7 months after the heatwaves. One octocoral species, Cladiella sp. 1, experienced bleaching and mortality, with some bleached colonies detaching from the reef structure during the heatwave (presumed dead). Those that remained attached to the benthos survived the event and recovered endosymbionts within 7 months of bleaching. Cladiella sp. 1 Symbiodiniaceae density (in cells per µg protein), chlorophyll a and c 2 per µg protein, and photosynthetic efficiency were significantly lower in bleached colonies compared to unbleached colonies, while chlorophyll a and c 2 per symbiont were higher. Interestingly, no other symbiotic octocoral species of the Lord Howe Island lagoonal reef bleached. Unbleached Xenia cf crassa colonies had higher Symbiodiniaceae and chlorophyll densities during the marine heatwave compared to other monitoring intervals, while Cladiella sp. 2 densities did not change substantially through time. Previous work on octocoral bleaching has focused primarily on gorgonian octocorals, while this study provides insight into bleaching variability in other octocoral groups. The study also provides further evidence that octocorals may be generally more resistant to bleaching than stony corals in many, but not all, reef ecosystems. Responses to marine heating events vary and should be assessed on a species by species basis.
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Fish gastro-intestinal system harbors diverse microbiomes that affect the host's digestion, nutrition, and immunity. Despite the great taxonomic diversity of fish, little is understood about fish microbiome and the factors that determine its structure and composition. Damselfish are important coral reef species that play pivotal roles in determining algae and coral population structures of reefs. Broadly, damselfish belong to either of two trophic guilds based on whether they are planktivorous or algae-farming. In this study, we used 16S rRNA gene sequencing to investigate the intestinal microbiome of 5 planktivorous and 5 algae-farming damselfish species (Pomacentridae) from the Great Barrier Reef. We detected Gammaproteobacteria ASVs belonging to the genus Actinobacillus in 80% of sampled individuals across the 2 trophic guilds, thus, bacteria in this genus can be considered possible core members of pomacentrid microbiomes. Algae-farming damselfish had greater bacterial alpha-diversity, a more diverse core microbiome and shared 35 ± 22 ASVs, whereas planktivorous species shared 7 ± 3 ASVs. Our data also highlight differences in microbiomes associated with both trophic guilds. For instance, algae-farming damselfish were enriched in Pasteurellaceae, whilst planktivorous damselfish in Vibrionaceae. Finally, we show shifts in bacterial community composition along the intestines. ASVs associated with the classes Bacteroidia, Clostridia, and Mollicutes bacteria were predominant in the anterior intestinal regions while Gammaproteobacteria abundance was higher in the stomach. Our results suggest that the richness of the intestinal bacterial communities of damselfish reflects host species diet and trophic guild.
O sistema gastro-intestinal de peixes abriga microbiomas diversos que afetam a digestão, nutrição e imunidade do hospedeiro. Apesar da grande diversidade taxonômica dos peixes, entende-se pouco sobre o microbioma dos peixes e fatores que determinam sua estrutura e composição. Peixes-donzela são espécies importantes em recifes de coral que exercem papéis pivotais na determinação da estrutura de algas e corais dos recifes. De forma geral, peixes-donzela pertencem à uma de duas guildas tróficas dependendo se são planctívoros ou algívoros. Nesse estudo, usamos sequenciamento do gene 16S rRNA para investigar o microbioma intestinal de cinco espécies planctívoras e cinco espécies algívoras de peixes-donzela (Pomacentridae) da Grande Barreira de Corais. Detectamos ASVs de Gammaproteobacteria pertencendo ao gênero Actinobacillus em 80% dos indivíduos amostrados nas duas guildas tróficas, logo, bactérias desse gênero podem ser consideradas como possíveis membros essenciais do microbioma dos pomacentrídeos. Peixes-donzela algívoros apresentaram uma maior alpha-diversidade bacteriana, um microbioma essencial mais diverso e compartilharam 35 ± 22 ASVs, e espécies planctívoras compartilharam 7 ± 3 ASVs. Nossos dados também ilustram diferenças nos microbiomas associados com ambas guildas tróficas. Por exemplo, peixes-donzela algívoros estavam enriquecidos em Pasteurellaceae, enquanto peixes-donzela planctívoros, em Vibrionaceae. Finalmente, demonstramos mudanças na composição da comunidade bacteriana associada com as classes Bacteroidia, Clostridia e Mollicutes foram predominantes nas regiões intestinais anteriores enquanto a abundância de Gammaproteobacteria foi maior no estômago. Nossos resultados sugerem que a riqueza das comunidades bacterianas intestinais de peixes-donzela refletem a dieta da espécie do hospedeiro, bem como a sua guilda trófica.
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Tracy Ainsworth and Barbara Brown introduce the causes and consequences of coral bleaching.
Assuntos
Antozoários/efeitos da radiação , Dinoflagellida/efeitos da radiação , Fotodegradação , Animais , Antozoários/fisiologia , Clorofila/metabolismo , Clorofila/efeitos da radiação , Cor , Conservação dos Recursos Naturais , Recifes de Corais , Dinoflagellida/fisiologia , Aquecimento Global , Temperatura Alta/efeitos adversos , Simbiose/fisiologia , Simbiose/efeitos da radiaçãoRESUMO
Researchers now recognize the importance of the coral microbiome, but they often overlook other species that live on corals and influence coral-microbe interactions. These 'interstitial associates' should be incorporated into the metaorganism concept for insights into how facilitations between associates, corals, and their microbiomes can be leveraged in ecology and restoration.
Assuntos
Antozoários/microbiologia , Organismos Aquáticos/metabolismo , Bactérias/metabolismo , Microbiota/fisiologia , Simbiose/fisiologia , Animais , Recifes de Corais , EcossistemaRESUMO
The enormous variability in richness, abundance and diversity of unknown bacterial organisms inhabiting the coral microbiome have challenged our understanding of their functional contribution to coral health. Identifying the attributes of the healthy meta-organism is paramount for contemporary approaches aiming to manipulate dysbiotic stages of the coral microbiome. This review evaluates the current knowledge on the structure and mechanisms driving bacterial communities in the coral microbiome and discusses two topics requiring further research to define the healthy coral microbiome. (i) We examine the necessity to establish microbial baselines to understand the spatial and temporal dynamics of the healthy coral microbiome and summarise conceptual and logistic challenges to consider in the design of these baselines. (ii) We propose potential mechanical, physical and chemical mechanisms driving bacterial distribution within coral compartments and suggest experiments to test them. Finally, we highlight aspects of the use of 16S amplicon sequencing requiring standardization and discuss its contribution to other multi-omics approaches.
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Antozoários/microbiologia , Bactérias/classificação , Bactérias/isolamento & purificação , Microbiota , Animais , Antozoários/crescimento & desenvolvimento , Bactérias/genética , Bactérias/crescimento & desenvolvimento , FilogeniaRESUMO
Bacterial diversity associated with corals has been studied extensively, however, localization of bacterial associations within the holobiont is still poorly resolved. Here we provide novel insight into the localization of coral-associated microbial aggregates (CAMAs) within tissues of the coral Acropora hyacinthus. In total, 318 and 308 CAMAs were characterized via histological and fluorescent in situ hybridization (FISH) approaches respectively, and shown to be distributed extensively throughout coral tissues collected from five sites in Japan and Australia. The densities of CAMAs within the tissues were negatively correlated with the distance from the coastline (i.e. lowest densities at offshore sites). CAMAs were randomly distributed across the six coral tissue regions investigated. Within each CAMA, bacterial cells had similar morphological characteristics, but bacterial morphologies varied among CAMAs, with at least five distinct types identified. Identifying the location of microorganisms associated with the coral host is a prerequisite for understanding their contributions to fitness. Localization of tissue-specific communities housed within CAMAs is particularly important, as these communities are potentially important contributors to vital metabolic functions of the holobiont.