-
Marine Drugs Oct 2023Reef-building corals, recognized as cornerstone species in marine ecosystems, captivate with their unique duality as both symbiotic partners and autotrophic entities.... (Review)
Review
Reef-building corals, recognized as cornerstone species in marine ecosystems, captivate with their unique duality as both symbiotic partners and autotrophic entities. Beyond their ecological prominence, these corals produce a diverse array of secondary metabolites, many of which are poised to revolutionize the domains of pharmacology and medicine. This exhaustive review delves deeply into the multifaceted world of coral-derived lipids, highlighting both ubiquitous and rare forms. Within this spectrum, we navigate through a myriad of fatty acids and their acyl derivatives, encompassing waxes, sterol esters, triacylglycerols, mono-akyl-diacylglycerols, and an array of polar lipids such as betaine lipids, glycolipids, sphingolipids, phospholipids, and phosphonolipids. We offer a comprehensive exploration of the intricate biochemical variety of these lipids, related fatty acids, prostaglandins, and both cyclic and acyclic oxilipins. Additionally, the review provides insights into the chemotaxonomy of these compounds, illuminating the fatty acid synthesis routes inherent in corals. Of particular interest is the symbiotic bond many coral species nurture with dinoflagellates from the Symbiodinium group; their lipid and fatty acid profiles are also detailed in this discourse. This exploration accentuates the vast potential and intricacy of coral lipids and underscores their profound relevance in scientific endeavors.
Topics: Animals; Anthozoa; Ecosystem; Fatty Acids; Prostaglandins; Coral Reefs; Dinoflagellida; Symbiosis
PubMed: 37888474
DOI: 10.3390/md21100539 -
ELife Aug 2023Algae living inside corals provide sugars for their host by digesting their own cell walls.
Algae living inside corals provide sugars for their host by digesting their own cell walls.
Topics: Animals; Nutrients; Anthozoa; Cell Wall
PubMed: 37594170
DOI: 10.7554/eLife.90916 -
Annual Review of Genetics Nov 2023Coral reefs are both exceptionally biodiverse and threatened by climate change and other human activities. Here, we review population genomic processes in coral reef... (Review)
Review
Coral reefs are both exceptionally biodiverse and threatened by climate change and other human activities. Here, we review population genomic processes in coral reef taxa and their importance for understanding responses to global change. Many taxa on coral reefs are characterized by weak genetic drift, extensive gene flow, and strong selection from complex biotic and abiotic environments, which together present a fascinating test of microevolutionary theory. Selection, gene flow, and hybridization have played and will continue to play an important role in the adaptation or extinction of coral reef taxa in the face of rapid environmental change, but research remains exceptionally limited compared to the urgent needs. Critical areas for future investigation include understanding evolutionary potential and the mechanisms of local adaptation, developing historical baselines, and building greater research capacity in the countries where most reef diversity is concentrated.
Topics: Animals; Humans; Coral Reefs; Anthozoa; Metagenomics; Genome; Biological Evolution; Climate Change; Ecosystem
PubMed: 37384733
DOI: 10.1146/annurev-genet-022123-102748 -
Science Advances Dec 2023Global climate change threatens tropical coral reefs, yet local management can influence resilience. While increasing anthropogenic nutrients reduce coral resistance and...
Global climate change threatens tropical coral reefs, yet local management can influence resilience. While increasing anthropogenic nutrients reduce coral resistance and recovery, it is unknown how the loss, or restoration, of natural nutrient flows affects reef recovery. Here, we test how natural seabird-derived nutrient subsidies, which are threatened by invasive rats, influence the mechanisms and patterns of reef recovery following an extreme marine heatwave using multiyear field experiments, repeated surveys, and Bayesian modeling. Corals transplanted from rat to seabird islands quickly assimilated seabird-derived nutrients, fully acclimating to new nutrient conditions within 3 years. Increased seabird-derived nutrients, in turn, caused a doubling of coral growth rates both within individuals and across entire reefs. Seabirds were also associated with faster recovery time of coral cover (<4 years) and more dynamic recovery trajectories of entire benthic communities. We conclude that restoring seabird populations and associated nutrient pathways may foster greater coral reef resilience through enhanced growth and recovery rates of corals.
Topics: Animals; Rats; Coral Reefs; Bayes Theorem; Resilience, Psychological; Anthozoa; Birds; Ecosystem
PubMed: 38055814
DOI: 10.1126/sciadv.adj0390 -
PeerJ 2024Clonal organisms like reef building corals exhibit a wide variety of colony morphologies and geometric shapes which can have many physiological and ecological...
Clonal organisms like reef building corals exhibit a wide variety of colony morphologies and geometric shapes which can have many physiological and ecological implications. Colony geometry can dictate the relationship between dimensions of volume, surface area, and length, and their associated growth parameters. For calcifying organisms, there is the added dimension of two distinct components of growth, biomass production and calcification. For reef building coral, basic geometric shapes can be used to model the inherent mathematical relationships between various growth parameters and how colony geometry determines which relationships are size-dependent or size-independent. Coral linear extension rates have traditionally been assumed to be size-independent. However, even with a constant calcification rate, extension rates can vary as a function of colony size by virtue of its geometry. Whether the ratio between mass and surface area remains constant or changes with colony size is the determining factor. For some geometric shapes, the coupling of biomass production (proportional to surface area productivity) and calcification (proportional to volume) can cause one aspect of growth to geometrically constrain the other. The nature of this relationship contributes to a species' life history strategy and has important ecological implications. At one extreme, thin diameter branching corals can maximize growth in surface area and resource acquisition potential, but this geometry requires high biomass production to cover the fast growth in surface area. At the other extreme, growth in large, hemispheroidal corals can be constrained by calcification. These corals grow surface area relatively slowly, thereby retaining a surplus capacity for biomass production which can be allocated towards other anabolic processes. For hemispheroidal corals, the rate of surface area growth rapidly decreases as colony size increases. This ontogenetic relationship underlies the success of microfragmentation used to accelerate restoration of coral cover. However, ontogenetic changes in surface area productivity only applies to certain coral geometries where surface area to volume ratios decrease with colony size.
Topics: Animals; Calcification, Physiologic; Calcinosis; Anthozoa; Biomass; Life History Traits
PubMed: 38436029
DOI: 10.7717/peerj.17037 -
Marine Environmental Research Nov 2023As a consequence of the increasing human footprint on the environment, marine ecosystems are rapidly transforming into new configurations dominated by early-successional...
As a consequence of the increasing human footprint on the environment, marine ecosystems are rapidly transforming into new configurations dominated by early-successional and weedy life forms. Algal turfs, in particular, are emerging as a common and widespread configuration of shallow temperate and tropical reefs, and are predicted to transform reef dynamics and ecosystem services. Restoration is an increasingly used approach to mitigate these transformations, with turf removal being proposed as a tool to shift back the competitive balance and facilitate the recovery of initial species, such as forest-forming seaweeds. Yet, our practical understanding of turf recovery trajectories following removal is limited, and removal success may be hindered by strong feedback mechanisms that reinforce turf dominance once turfs are established. Here we investigate the recovery of algal turfs and their properties (mean height, turf biomass and sediment load) to experimental clearance across six turf-dominated reefs at ca. 9 m in subtropical western Australia. Turf cover, mean height, and sediment loads exhibited a rapid recovery following experimental clearing, with all experimental sites reaching pre-clearing turf conditions between 28 and 46 days. This response was mostly driven by the growth of filamentous turf species, whose cover exhibited a positive relationship with sediment load, and are well-known to rapidly recover after disturbance. Turf abundance and turf properties remained relatively constant for the remaining experimental period. Our results suggest that clearing turfs creates only a small time window for recovery of seaweed forests, which limits the effectiveness of turf clearing as a restoration tool. System-specific quantitative evidence on the recovery capacity of turfs may thus be necessary to guide restoration initiatives and develop decision support systems that account for the risks, feasibility, and costs and benefits of restoring turf-dominated systems to previous configurations.
Topics: Humans; Animals; Ecosystem; Geologic Sediments; Forests; Biomass; Seaweed; Coral Reefs; Anthozoa
PubMed: 37797426
DOI: 10.1016/j.marenvres.2023.106185 -
ELife Oct 2023Jellyfish and sea anemones fire single-use, venom-covered barbs to immobilize prey or predators. We previously showed that the anemone uses a specialized voltage-gated...
Jellyfish and sea anemones fire single-use, venom-covered barbs to immobilize prey or predators. We previously showed that the anemone uses a specialized voltage-gated calcium (Ca) channel to trigger stinging in response to synergistic prey-derived chemicals and touch (Weir et al., 2020). Here, we use experiments and theory to find that stinging behavior is suited to distinct ecological niches. We find that the burrowing anemone uses uniquely strong Ca inactivation for precise control of predatory stinging. In contrast, the related anemone inhabits exposed environments to support photosynthetic endosymbionts. Consistent with its niche, indiscriminately stings for defense and expresses a Ca splice variant that confers weak inactivation. Chimeric analyses reveal that Caβ subunit adaptations regulate inactivation, suggesting an evolutionary tuning mechanism for stinging behavior. These findings demonstrate how functional specialization of ion channel structure contributes to distinct organismal behavior.
Topics: Animals; Sea Anemones; Biological Evolution; Venoms
PubMed: 37906220
DOI: 10.7554/eLife.88900 -
F1000Research 2023Anemonefishes are an iconic group of coral reef fish particularly known for their mutualistic relationship with sea anemones. This mutualism is especially intriguing as... (Review)
Review
Anemonefishes are an iconic group of coral reef fish particularly known for their mutualistic relationship with sea anemones. This mutualism is especially intriguing as it likely prompted the rapid diversification of anemonefish. Understanding the genomic architecture underlying this process has indeed become one of the holy grails of evolutionary research in these fishes. Recently, anemonefishes have also been used as a model system to study the molecular basis of highly complex traits such as color patterning, social sex change, larval dispersal and life span. Extensive genomic resources including several high-quality reference genomes, a linkage map, and various genetic tools have indeed enabled the identification of genomic features controlling some of these fascinating attributes, but also provided insights into the molecular mechanisms underlying adaptive responses to changing environments. Here, we review the latest findings and new avenues of research that have led to this group of fish being regarded as a model for evolutionary genomics.
Topics: Animals; Perciformes; Biological Evolution; Genomics; Fishes; Sea Anemones
PubMed: 37928172
DOI: 10.12688/f1000research.130752.2 -
Annual Review of Genetics Nov 2023Symbiotic interactions occur in all domains of life, providing organisms with resources to adapt to new habitats. A prime example is the endosymbiosis between corals and... (Review)
Review
Symbiotic interactions occur in all domains of life, providing organisms with resources to adapt to new habitats. A prime example is the endosymbiosis between corals and photosynthetic dinoflagellates. Eukaryotic dinoflagellate symbionts reside inside coral cells and transfer essential nutrients to their hosts, driving the productivity of the most biodiverse marine ecosystem. Recent advances in molecular and genomic characterization have revealed symbiosis-specific genes and mechanisms shared among symbiotic cnidarians. In this review, we focus on the cellular and molecular processes that underpin the interaction between symbiont and host. We discuss symbiont acquisition via phagocytosis, modulation of host innate immunity, symbiont integration into host cell metabolism, and nutrient exchange as a fundamental aspect of stable symbiotic associations. We emphasize the importance of using model systems to dissect the cellular complexity of endosymbiosis, which ultimately serves as the basis for understanding its ecology and capacity to adapt in the face of climate change.
Topics: Animals; Anthozoa; Symbiosis; Ecosystem; Dinoflagellida; Systems Analysis
PubMed: 37722685
DOI: 10.1146/annurev-genet-072320-125436