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Proceedings of the National Academy of... Sep 2017Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The...
Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The classical model assumes precipitation in contrast with observed "vital effects," that is, deviations from elemental and isotopic compositions at thermodynamic equilibrium. Here, we show direct spectromicroscopy evidence in corals that two amorphous precursors exist, one hydrated and one anhydrous amorphous calcium carbonate (ACC); that these are formed in the tissue as 400-nm particles; and that they attach to the surface of coral skeletons, remain amorphous for hours, and finally, crystallize into aragonite (CaCO). We show in both coral and synthetic aragonite spherulites that crystal growth by attachment of ACC particles is more than 100 times faster than ion-by-ion growth from solution. Fast growth provides a distinct physiological advantage to corals in the rigors of the reef, a crowded and fiercely competitive ecosystem. Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed. If this is how other corals form their skeletons, perhaps this is how a few corals survived past CO increases, such as the Paleocene-Eocene Thermal Maximum that occurred 56 Mya.
Topics: Animals; Anthozoa; Calcification, Physiologic; Calcium Carbonate; Coral Reefs; Crystallization; Ecosystem; Hydrogen-Ion Concentration; Minerals; Seawater
PubMed: 28847944
DOI: 10.1073/pnas.1707890114 -
Proceedings. Biological Sciences Jan 2022Evidence is mounting that composition of microorganisms within a host can play an essential role in total holobiont health. In corals, for instance, studies have...
Evidence is mounting that composition of microorganisms within a host can play an essential role in total holobiont health. In corals, for instance, studies have identified algal and bacterial taxa that can significantly influence coral host function and these communities depend on environmental context. However, few studies have linked host genetics to algal and microbial partners across environments within a single coral population. Here, using 2b-RAD sequencing of corals and metabarcoding of their associated algal (ITS2) and bacterial (16S) communities, we show evidence that reef zones (locales that differ in proximity to shore and other environmental characteristics) structure algal and bacterial communities at different scales in a highly connected coral population () in French Polynesia. Fore reef (FR) algal communities in Mo'orea were more diverse than back reef (BR) communities, suggesting that these BR conditions constrain diversity. Interestingly, in FR corals, host genetic diversity correlated with bacterial diversity, which could imply genotype by genotype interactions between these holobiont members. Our results illuminate that local reef conditions play an important role in shaping unique host-microbial partner combinations, which may have fitness consequences for dispersive coral populations arriving in novel environments.
Topics: Animals; Anthozoa; Bacteria; Coral Reefs; Polynesia
PubMed: 35042418
DOI: 10.1098/rspb.2021.2459 -
PloS One 2018Global environmental change has the potential to disrupt well established species interactions, with impacts on nutrient cycling and ecosystem function. On coral reefs,...
Global environmental change has the potential to disrupt well established species interactions, with impacts on nutrient cycling and ecosystem function. On coral reefs, fish living within the branches of coral colonies can promote coral performance, and it has been hypothesized that the enhanced water flow and nutrients provided by fish to corals could ameliorate coral bleaching. The aim of this study was to evaluate the influence of small, aggregating damselfish on the health of their host corals (physiology, recovery, and survival) before, during, and after a thermal-bleaching event. When comparing coral colonies with and without fish, those with resident fish exhibited higher Symbiodinium densities and chlorophyll in both field and experimentally-induced bleaching conditions, and higher protein concentrations in field colonies. Additionally, colonies with damselfish in aquaria exhibited both higher photosynthetic efficiency (FV/FM) during bleaching stress and post-bleaching recovery, compared to uninhabited colonies. These results demonstrate that symbiotic damselfishes, and the services they provide, translate into measureable impacts on coral tissue, and can influence coral bleaching susceptibility/resilience and recovery. By mediating how external abiotic stressors influence coral colony health, damselfish can affect the functional responses of these interspecific interactions in a warming ocean.
Topics: Animals; Anthozoa; Chlorophyll; Coral Reefs; Fishes; Photosynthesis; Symbiosis; Temperature
PubMed: 30550591
DOI: 10.1371/journal.pone.0208545 -
FEMS Microbiology Letters Mar 2019The enormous variability in richness, abundance and diversity of unknown bacterial organisms inhabiting the coral microbiome have challenged our understanding of their... (Review)
Review
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.
Topics: Animals; Anthozoa; Bacteria; Microbiota; Phylogeny
PubMed: 30939203
DOI: 10.1093/femsle/fnz063 -
PeerJ 2024, a prized resource in Japan, plays a vital role in traditional arts and fishing industries. Because of diminished stock due to overexploitation, ongoing efforts are...
BACKGROUND
, a prized resource in Japan, plays a vital role in traditional arts and fishing industries. Because of diminished stock due to overexploitation, ongoing efforts are focused on restoration through transplantation. This study aimed to enhance our understanding of the reproductive biology of these valuable corals and find more efficient methods for sex determination, which may significantly contribute to conservation initiatives.
METHODS
We used 12 three-month aquarium reared colony fragments, conducted histological analysis for maturity and sex verification, and performed transcriptome analysis via assembly and mapping using the transcriptome to explore gene expression differences between female and male .
RESULTS
Our histological observations enabled sex identification in 33% of incompletely mature samples. However, the sex of the remaining 67% of samples, classified as immature, could not be identified. RNA-seq yielded approximately 21-31 million short reads from 12 samples. assembly yielded 404,439 highly expressed transcripts. Among them, 855 showed significant differential expression, with 786 differentially expressed transcripts between females and males. Heatmap analysis highlighted 283 female-specific and 525 male-specific upregulated transcripts. Transcriptome assembly mapped to yielded 28,092 contigs, leading to the identification of 190 highly differentially expressed genes, with 113 upregulated exclusively in females and 70 upregulated exclusively in males. Blastp analysis provided putative protein annotations for 83 female and 72 male transcripts. Annotation analysis revealed that female biological processes were related to oocyte proliferation and reproduction, whereas those in males were associated with cell adhesion.
DISCUSSION
Transcriptome analysis revealed sex-specific gene upregulation in incompletely mature and shared transcripts with , providing insight into its gene expression patterns. This study highlights the importance of using both and reference-based assembly methods. Functional enrichment analysis showed that females exhibited enrichment in cell proliferation and reproduction pathways, while males exhibited enrichment in cell adhesion pathways. To the best of our knowledge, this is the first report on the gene expressions of each sex during the spawning season. Our findings offer valuable insights into the physiological ecology of incompletely mature red Japanese precious corals and suggest a method for identifying sex using various genes expressed in female and male individuals. In the future, techniques such as transplantation, artificial fertilization, and larval rearing may involve sex determination methods based on differences in gene expression to help conserve precious coral resources and ecosystems.
Topics: Animals; Female; Male; Anthozoa; Gametogenesis; Gene Expression Profiling; Japan; Transcriptome
PubMed: 38646482
DOI: 10.7717/peerj.17182 -
Nature Microbiology Jun 2021Alveolata comprises diverse taxa of single-celled eukaryotes, many of which are renowned for their ability to live inside animal cells. Notable examples are apicomplexan...
Alveolata comprises diverse taxa of single-celled eukaryotes, many of which are renowned for their ability to live inside animal cells. Notable examples are apicomplexan parasites and dinoflagellate symbionts, the latter of which power coral reef ecosystems. Although functionally distinct, they evolved from a common, free-living ancestor and must evade their host's immune response for persistence. Both the initial cellular events that gave rise to this intracellular lifestyle and the role of host immune modulation in coral-dinoflagellate endosymbiosis are poorly understood. Here, we use a comparative approach in the cnidarian endosymbiosis model Aiptasia, which re-establishes endosymbiosis with free-living dinoflagellates every generation. We find that uptake of microalgae is largely indiscriminate, but non-symbiotic microalgae are expelled by vomocytosis, while symbionts induce host cell innate immune suppression and form a lysosomal-associated membrane protein 1-positive niche. We demonstrate that exogenous immune stimulation results in symbiont expulsion and, conversely, inhibition of canonical Toll-like receptor signalling enhances infection of host animals. Our findings indicate that symbiosis establishment is dictated by local innate immune suppression, to circumvent expulsion and promote niche formation. This work provides insight into the evolution of the cellular immune response and key steps involved in mediating endosymbiotic interactions.
Topics: Animals; Anthozoa; Coral Reefs; Dinoflagellida; Immunity, Innate; Signal Transduction; Symbiosis
PubMed: 33927382
DOI: 10.1038/s41564-021-00897-w -
Zootaxa Aug 2016This book inventories all available (and some unavailable) names in the family, genus, and species groups of extant members of orders Actiniaria and Corallimorpharia...
This book inventories all available (and some unavailable) names in the family, genus, and species groups of extant members of orders Actiniaria and Corallimorpharia [cnidarian subclass Hexacorallia (Zoantharia) of class Anthozoa], providing a benchmark of names, their status, and taxon membership. I have attempted to make the compilation complete as of 2010; some names created after 2010 are included. The book is derived from a database I compiled that was available through a website. Most of the book is from the literature that defines taxa and documents their geographic distribution-primarily publications on nomenclature, taxonomy, and biogeography, but also some on ecology, pharmacology, reproductive biology, physiology, etc. of anemones (the common name for these groups); the reference section comprises 845 entries. As for previous anemone catalogs, this contains taxonomic as well as nomenclatural information, the former based on subjective opinion of working biologists, the latter objectively verifiable and unchanging (except by action of the International Commission on Zoological Nomenclature). Each family-group name, genus-group name, and original combination for species-group names has an entry. The entry contains the bibliographic reference to the publication in which each name was made available. This book contains for Corallimorpharia seven family names (four considered valid [57%]), 20 generic names (10 considered valid [50%] and one unavailable), and 65 species names (46 considered valid [70%]). It contains for Actiniaria 86 family names (50 considered valid [58%] and three unavailable), 447 generic names (264 considered valid [59%] and two unavailable), and 1427 species names (1101 considered valid [77%] and nine unavailable). Type specimens are inventoried from more than 50 natural history museums in Africa, Australia, Europe, New Zealand, and North America, including those with the largest collections of anemones; the geographic sources of specimens that were the bases of new names are identified. I resolve some nomenclatural issues, acting as First Reviser. A few taxonomic opinions are published for the first time. I have been unable to resolve a small number of problematic names having both nomenclatural and taxonomic problems. Molecular phylogenetic analyses are changing assignment of genera to families and species to genera. Systematics may change, but the basics of nomenclature remain unchanged in face of such alterations. All actions are in accord with the principles of nomenclature enunciated in the International Code of Zoological Nomenclature. These include the type concept, the Principle of Coordination, and the Principle of Priority. Nomenclatural acts include the creation of new replacement names; seven actiniarian generic names and one species name that are junior homonyms but have been treated as valid are replaced and an eighth new genus name is created. I designate type species for two genera. Except for published misspellings, names are rendered correctly according to the International Code of Zoological Nomenclature; I have altered spelling of some species names to conform to orthographic regulations. I place several species that had been assigned to genera now considered junior synonyms in the genus to which the type species was moved; experts on these anemones should determine whether those generic placements, which follow the nomenclatural rules, are taxonomically appropriate. This inventory can be a useful starting point in assembling the literature and trying to understand the rationale for the creation and use of names for the taxonomic matters yet to be resolved. Some nomenclatural conundra will not be resolved until taxonomic uncertainties are. A taxonomist familiar with the animals needs to ascertain whether the published synonymies are justified. If so, the senior synonym should be used, which, in many instances, will involve determining the proper generic assignment of the species and the correct rendering of the name; if changing the name would be disruptive, retaining the junior name would require an appeal to the Commission (Code Article 23.11).
Topics: Animal Distribution; Animals; Anthozoa; Species Specificity; Terminology as Topic
PubMed: 27515599
DOI: 10.11646/zootaxa.4145.1.1 -
Annual Review of Marine Science Jan 2020Ocean ecosystems are experiencing unprecedented rates of climate and anthropogenic change, which can often initiate stress in marine organisms. Symbioses, or... (Review)
Review
Ocean ecosystems are experiencing unprecedented rates of climate and anthropogenic change, which can often initiate stress in marine organisms. Symbioses, or associations between different organisms, are plentiful in the ocean and could play a significant role in facilitating organismal adaptations to stressful ocean conditions. This article reviews current knowledge about the role of symbiosis in marine organismal acclimation and adaptation. It discusses stress and adaptations in symbioses from coral reef ecosystems, which are among the most affected environments in the ocean, including the relationships between corals and microalgae, corals and bacteria, anemones and clownfish, and cleaner fish and client fish. Despite the importance of this subject, knowledge of how marine organisms adapt to stress is still limited, and there are vast opportunities for research and technological development in this area. Attention to this subject will enhance our understanding of the capacity of symbioses to alleviate organismal stress in the oceans.
Topics: Adaptation, Physiological; Animals; Anthozoa; Aquatic Organisms; Bacteria; Climate Change; Fishes; Oceans and Seas; Stress, Physiological; Symbiosis
PubMed: 31283425
DOI: 10.1146/annurev-marine-010419-010641 -
Scientific American Dec 2017
Topics: Adaptation, Physiological; Animals; Anthozoa; Australia; Conservation of Natural Resources; Coral Reefs; Endangered Species; Genetic Variation; Global Warming; Reproduction; Reproduction, Asexual
PubMed: 29257818
DOI: 10.1038/scientificamerican0118-42 -
Proceedings. Biological Sciences Oct 2017Ecological damage from periodic environmental extremes is often repaired in resilient ecosystems, but the rate of return to a non-damaged state is critical. Measures of...
Ecological damage from periodic environmental extremes is often repaired in resilient ecosystems, but the rate of return to a non-damaged state is critical. Measures of recovery of communities include biomass, productivity and diversity, while measures of recovery of individuals tend to focus on physiological conditions and the return to normal metabolic functioning. Transcriptomics offers a window into the entire physiology of the organism under stress and can represent a holistic view of organismal recovery. In this study, we track the recovery of seven colonies of following a natural bleaching event. We identified a large environmental stress response in the field that involved approximately 20% of the host transcriptome. The transcriptome remained largely perturbed for at least six months after temperatures had cooled and four months after symbiont populations had recovered. Moreover, a small set of genes did not recover to previous expression levels even 12 months after the event, about the time that normal growth rates resumed. This study is among the first to incorporate transcriptomics into a longitudinal dataset of recovery from environmental stress. The data demonstrate large and lasting effects on coral physiology long after environmental conditions return to normal and symbiont populations recover.
Topics: Animals; Anthozoa; Dinoflagellida; Genomics; Stress, Physiological; Symbiosis; Temperature; Transcriptome
PubMed: 29070726
DOI: 10.1098/rspb.2017.1790