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Learning & Behavior Jun 2021Using the database Web of Science, a systematic search for literature on learning in Cnidaria, both non-associative and associative, was conducted. Cnidaria comprise... (Review)
Review
Using the database Web of Science, a systematic search for literature on learning in Cnidaria, both non-associative and associative, was conducted. Cnidaria comprise hydras, box jellies, (true) jellyfish, corals, and sea anemones, a group of animals possessing diffuse networks of nerves known as nerve nets or neural nets. Being neighbors on the animal evolutionary tree to bilaterian animals, the vast collection of (mostly) bilaterally symmetric animals with brains ranging from tiny worms to giant whales, the cognitive capacities of Cnidaria inform the evolution of nervous systems and cognition in bilateria. I failed to find literature on learning in corals and box jellies. Habituation has been amply shown in hydras, jellyfish, and sea anemones, while sensitization has been studied in detail in sea anemones, including some neurobiological details in the release of nematocysts or poisoned darts for capturing prey. One well-controlled study found evidence for classical conditioning with shock in sea anemones, in addition to two other lesser-controlled demonstrations. The relevance of associative learning in sea anemones, embodied cognition, and representationsal issues when it comes to animals without central brains is discussed.
Topics: Animals; Conditioning, Classical; Sea Anemones
PubMed: 33439470
DOI: 10.3758/s13420-020-00452-3 -
The Science of the Total Environment Jan 2023Chronic exposure of coral reefs to elevated nutrient conditions can modify the performance of the coral holobiont and shift the competitive interactions of reef... (Meta-Analysis)
Meta-Analysis Review
Chronic exposure of coral reefs to elevated nutrient conditions can modify the performance of the coral holobiont and shift the competitive interactions of reef organisms. Many studies have now quantified the links between nutrients and coral performance, but few have translated these studies to directly address coastal water quality standards. To address this management need, we conducted a systematic review of peer-reviewed studies, public reports, and gray literature that examined the impacts of dissolved inorganic nitrogen (DIN: nitrate, nitrite, and ammonium) and dissolved inorganic phosphorus (DIP: phosphate) on scleractinian corals. The systematic review resulted in 47 studies with comparable data on coral holobiont responses to nutrients: symbiont density, chlorophyll a (chl-a) concentration, photosynthesis, photosynthetic efficiency, growth, calcification, adult survival, juvenile survival, and fertilization. Mixed-effects meta-regression meta-analyses were used to determine the magnitude of the positive or negative effects of DIN and DIP on coral responses. Zooxanthellae density (DIN & DIP), chl-a concentration (DIN), photosynthetic rate (DIN), and growth (DIP) all exhibited positive responses to nutrient addition; maximum quantum yield (DIP), growth (DIN), larval survival (DIN), and fertilization (DIN) exhibited negative responses. In lieu of developing specific thresholds for the management of nutrients as a stressor on coral reefs, we highlight important inflection points in the magnitude and direction of the effects of inorganic nutrients and identify trends among coral responses. The responses of corals to nutrients are complex, warranting conservative guidelines for elevated nutrient concentrations on coral reefs.
Topics: Animals; Anthozoa; Chlorophyll A; Coral Reefs; Nitrogen; Nutrients
PubMed: 36183766
DOI: 10.1016/j.scitotenv.2022.159093 -
Marine Environmental Research Dec 2022Reef environments are rapidly transforming worldwide, and these changes are causing major impacts to the reef ecosystem. Scientific knowledge is strategic for marine... (Review)
Review
Reef environments are rapidly transforming worldwide, and these changes are causing major impacts to the reef ecosystem. Scientific knowledge is strategic for marine conservation and management in these scenarios. Aiming to contribute to this subject, a systematic review from 1967 to 2020 was conducted, in order to identify gaps in studies regarding reef fish species, ecosystem components and processes. Multidisciplinary sciences concerning reef fish have been rising, mainly in the fields of basic biology and ecology. Besides that, phase shifts and ecosystem services were absent terms in the analyzes of co-occurrence. Research in the ethnosciences needs to be increased, and will improve access to local ecological knowledge, which can be used as a tool to address issues in reef environments. Socio-ecological systems are components of this landscape that has had few publications. The participation in the elaboration of public policies can be a new avenue to foster the biodiversity of reef environments.
Topics: Animals; Ecosystem; Coral Reefs; Anthozoa; Conservation of Natural Resources; Biodiversity; Fishes
PubMed: 36272222
DOI: 10.1016/j.marenvres.2022.105769 -
Environmental Microbiology Oct 2022Bacteria within the phylum Bacteroidota (Bacteroidetes) are known to cause devastating and widespread disease outbreaks in marine eukaryotic hosts. However, with few... (Review)
Review
Bacteria within the phylum Bacteroidota (Bacteroidetes) are known to cause devastating and widespread disease outbreaks in marine eukaryotic hosts. However, with few pathogens described in detail, their prevalence and virulence strategies remain largely unknown. Here, we systematically reviewed the literature to evaluate the current understanding of Bacteroidota that cause disease in marine hosts. Isolates affiliated with the genera Tenacibaculum and Aquimarina (Flavobacteriaceae) were the most widely reported and characterized pathogens. Although cultured isolates were predominantly Flavobacteriia, culture-independent studies also found classes Bacteroidia, Cytophagia and Sphingobacteriia associated with disease. We found that pathogenic marine Bacteroidota largely conformed to an opportunistic lifestyle but could also act as secondary pathogens or were involved in polymicrobial diseases. Many diseases were also associated with an environmental stressor, especially those affecting coral, macroalgae and fish. Key virulence traits included the production of adhesins and host tissue-degrading enzymes. Overall, the nature of disease involving Bacteroidota pathogens appears to be an outcome of complex host-pathogen-environment interactions; however, our understanding of virulence remains limited by the lack of functional characterization studies. This is concerning as Bacteroidota have the potential to emerge as a serious threat to marine ecosystems and aquaculture industries, driven by global changes in ocean conditions.
Topics: Animals; Anthozoa; Ecosystem; Fish Diseases; Flavobacteriaceae; Oceans and Seas; Tenacibaculum
PubMed: 35706128
DOI: 10.1111/1462-2920.16094 -
Nature Communications Aug 2023Microorganisms play essential roles in the health and resilience of cnidarians. Understanding the factors influencing cnidarian microbiomes requires cross study...
Microorganisms play essential roles in the health and resilience of cnidarians. Understanding the factors influencing cnidarian microbiomes requires cross study comparisons, yet the plethora of protocols used hampers dataset integration. We unify 16S rRNA gene sequences from cnidarian microbiome studies under a single analysis pipeline. We reprocess 12,010 cnidarian microbiome samples from 186 studies, alongside 3,388 poriferan, 370 seawater samples, and 245 cultured Symbiodiniaceae, unifying ~6.5 billion sequence reads. Samples are partitioned by hypervariable region and sequencing platform to reduce sequencing variability. This systematic review uncovers an incredible diversity of 86 archaeal and bacterial phyla associated with Cnidaria, and highlights key bacteria hosted across host sub-phylum, depth, and microhabitat. Shallow (< 30 m) water Alcyonacea and Actinaria are characterized by highly shared and relatively abundant microbial communities, unlike Scleractinia and most deeper cnidarians. Utilizing the V4 region, we find that cnidarian microbial composition, richness, diversity, and structure are primarily influenced by host phylogeny, sampling depth, and ocean body, followed by microhabitat and sampling date. We identify host and geographical generalist and specific Endozoicomonas clades within Cnidaria and Porifera. This systematic review forms a framework for understanding factors governing cnidarian microbiomes and creates a baseline for assessing stress associated dysbiosis.
Topics: Animals; RNA, Ribosomal, 16S; Microbiota; Bacteria; Archaea; Anthozoa; Phylogeny
PubMed: 37580316
DOI: 10.1038/s41467-023-39876-6 -
Marine Environmental Research Jan 2023Coral reefs are the most diverse marine ecosystems. However, coral cover has decreased worldwide due to natural disturbances, climate change, and local anthropogenic... (Review)
Review
Coral reefs are the most diverse marine ecosystems. However, coral cover has decreased worldwide due to natural disturbances, climate change, and local anthropogenic drivers. In recent decades, various genetic methods and molecular markers have been developed to assess genetic diversity, structure, and connectivity in different coral species to determine the vulnerability of their populations. This review aims to identify population genetic studies of scleractinian corals in the last decade (2010-2020), and the techniques and molecular markers used. Bibliometric analysis was conducted to identify journals and authors working in this field. We then calculated the number of genetic studies by species and ecoregion based on data obtained from 178 studies found in Scopus and Web of Science. Coral Reefs and Molecular Ecology were the main journals published population genetics studies, and microsatellites are the most widely used molecular markers. The Caribbean, Australian Barrier Reef, and South Kuroshio in Japan are among the ecoregions with the most population genetics data. In contrast, we found limited information about the Coral Triangle, a region with the highest biodiversity and key to coral reef conservation. Notably, only 117 (out of 1500 described) scleractinian coral species have genetic studies. This review emphasizes which coral species have been studied and highlights remaining gaps and locations where such data is critical for coral conservation.
Topics: Animals; Anthozoa; Ecosystem; Australia; Coral Reefs; Genetics, Population
PubMed: 36371949
DOI: 10.1016/j.marenvres.2022.105781 -
Journal of Environmental Management Mar 2018Coral reef ecosystems and the people who depend on them are increasingly exposed to the adverse effects of global environmental change (GEC), including increases in... (Review)
Review
Coral reef ecosystems and the people who depend on them are increasingly exposed to the adverse effects of global environmental change (GEC), including increases in sea-surface temperature and ocean acidification. Managers and decision-makers need a better understanding of the options available for action in the face of these changes. We refine a typology of actions developed by Gattuso et al. (2015) that could serve in prioritizing strategies to deal with the impacts of GEC on reefs and people. Using the typology we refined, we investigate the scientific effort devoted to four types of management strategies: mitigate, protect, repair, adapt that we tie to the components of the chain of impact they affect: ecological vulnerability or social vulnerability. A systematic literature review is used to investigate quantitatively how scientific effort over the past 25 years is responding to the challenge posed by GEC on coral reefs and to identify gaps in research. A growing literature has focused on these impacts and on management strategies to sustain coral reef social-ecological systems. We identify 767 peer reviewed articles published between 1990 and 2016 that address coral reef management in the context of GEC. The rate of publication of such studies has increased over the years, following the general trend in climate research. The literature focuses on protect strategies the most, followed by mitigate and adapt strategies, and finally repair strategies. Developed countries, particularly Australia and the United States, are over-represented as authors and locations of case studies across all types of management strategies. Authors affiliated in developed countries play a major role in investigating case studies across the globe. The majority of articles focus on only one of the four categories of actions. A gap analysis reveals three directions for future research: (1) more research is needed in South-East Asia and other developing countries where the impacts of GEC on coral reefs will be the greatest, (2) more scholarly effort should be devoted to understanding how adapt and repair strategies can deal with the impacts of GEC, and (3) the simultaneous assessment of multiple strategies is needed to understand trade-offs and synergies between actions.
Topics: Animals; Anthozoa; Australia; Climate Change; Conservation of Natural Resources; Coral Reefs; Ecosystem
PubMed: 29309969
DOI: 10.1016/j.jenvman.2017.12.051 -
Global Change Biology Mar 2022Non-random community changes are becoming more frequent in many ecosystems. In coral reefs, changes towards communities dominated by other than hard corals are... (Meta-Analysis)
Meta-Analysis Review
Non-random community changes are becoming more frequent in many ecosystems. In coral reefs, changes towards communities dominated by other than hard corals are increasing in frequency, with severe impacts on ecosystem functioning and provision of ecosystem services. Although new research suggests that a variety of alternative communities (i.e. not dominated by hard corals) exist, knowledge on the global diversity and functioning of alternative coral reef benthic communities, especially those not dominated by algae, remains scattered. In this systematic review and meta-analysis of 523 articles, we analyse the different coral reef benthic community changes reported to date and discuss the advantages and limitations of the methods used to study these changes. Furthermore, we used field cover data (1116 reefs from the ReefCheck database) to explore the biogeographic and latitudinal patterns in dominant benthic organisms. We found a mismatch between literature focus on coral-algal changes (over half of the studies analysed) and observed global natural patterns. We identified strong biogeographic patterns, with the largest and most biodiverse biogeographic regions (Western and Central Indo-Pacific) presenting previously overlooked soft-coral-dominated communities as the most abundant alternative community. Finally, we discuss the potential biases associated with methods that overlook ecologically important cryptobenthic communities and the potential of new technological advances in improving monitoring efforts. As coral reef communities inevitably and swiftly change under changing ocean conditions, there is an urgent need to better understand the distribution, dynamics as well as the ecological and societal impacts of these new communities.
Topics: Animals; Anthozoa; Biodiversity; Coral Reefs; Ecosystem
PubMed: 34951504
DOI: 10.1111/gcb.16034 -
The Science of the Total Environment Nov 2021Reduced water quality degrades coral reefs, resulting in compromised ecosystem function and services to coastal communities. Increasing management capacity on reefs... (Meta-Analysis)
Meta-Analysis Review
Reduced water quality degrades coral reefs, resulting in compromised ecosystem function and services to coastal communities. Increasing management capacity on reefs requires prioritization of the development of data-based water-quality thresholds and tipping points. To meet this urgent need of marine resource managers, we conducted a systematic review and meta-analysis that quantified the effects on scleractinian corals of chemical pollutants from land-based and atmospheric sources. We compiled a global dataset addressing the effects of these pollutants on coral growth, mortality, reproduction, physiology, and behavior. The resulting quantitative review of 55 articles includes information about industrial sources, modes of action, experimentally tested concentrations, and previously identified tolerance thresholds of corals to 13 metals, 18 pesticides, 5 polycyclic aromatic hydrocarbons (PAHs), a polychlorinated biphenyl (PCB), and a pharmaceutical. For data-rich contaminants, we make more robust threshold estimates by adapting models for Bayesian hierarchical meta-analysis that were originally developed for biopharmaceutical application. These models use information from multiple studies to characterize the dose-response relationships (i.e., E curves) between a pollutant's concentration and various measures of coral health. Metals used in antifouling paints, especially copper, have received a great deal of attention to-date, thus enabling us to estimate the cumulative impact of copper across coral's early life-history. The effects of other land-based pollutants on corals are comparatively understudied, which precludes more quantitative analysis. We discuss opportunities to improve future research so that it can be better integrated into quantitative assessments of the effects of more pollutant types on sublethal coral stress-responses. We also recommend that managers use this information to establish more conservative water quality thresholds that account for the synergistic effects of multiple pollutants on coral reefs. Ultimately, active remediation of local stressors will improve the resistance, resilience, and recovery of individual reefs and reef ecosystems facing the global threat of climate change.
Topics: Animals; Anthozoa; Bayes Theorem; Coral Reefs; Ecosystem; Water Quality
PubMed: 34323749
DOI: 10.1016/j.scitotenv.2021.148632 -
The Science of the Total Environment Jun 2023The impact of petroleum exploitation and oil spills in marine ecosystems has increased over time. Among the concerns regarding these events, the impact on coral reefs... (Review)
Review
The impact of petroleum exploitation and oil spills in marine ecosystems has increased over time. Among the concerns regarding these events, the impact on coral reefs stand out because this ecosystem has ecological and economic importance and is globally threatened. We performed a systematic review and bibliometric analysis of studies that determine polycyclic aromatic hydrocarbons (PAHs) in coral reefs, attempting to answer how the studies were distributed around the globe, the main environmental matrices and species of coral studied, the main PAHs found and their mean concentrations, and the methodology used. A bibliographic search resulted in 42 studies with worldwide distribution. The bibliometric results presented more explored terms, such as sediments and toxicology, and newly investigated terms, which should encourage a new area of study, such as those related to zooxanthellae and mucus. The main matrices studied in coral reefs are sediments, corals, and water, whereas air and other invertebrates have rarely been studied. Approximately 45 species of corals with several morphotypes have been reported. PAHs recommended by the United States Environmental Protection Agency (US EPA) were analyzed in all studies, while additional compounds were analyzed in only five. The methods used to determine hydrocarbons are predominantly the most traditional; however, for corals, studies have tended to separate tissue, zooxanthellae, skeleton, and mucus. In the future, we recommend investment in improving the capacity to detect non-conventional PAHs, more studies in regions that are rarely explored in developing countries, and the creation of databases to facilitate management planning on marine coasts.
Topics: Animals; Coral Reefs; Anthozoa; Ecosystem; Polycyclic Aromatic Hydrocarbons; Environmental Monitoring; Water Pollutants, Chemical
PubMed: 36934938
DOI: 10.1016/j.scitotenv.2023.162868