Coral Skeleton | ScienceGate

AbstractEndolithic microbial symbionts in the coral skeleton may play a pivotal role in maintaining coral health. However, compared to aerobic microorganisms, research on the roles of endolithic anaerobic microorganisms and microbe-microbe interactions in the coral skeleton are still in their infancy. In our previous study, we showed that a group of coral-associated Prosthecochloris (CAP), a genus of anaerobic green sulfur bacteria, was dominant in the skeleton of the coral Isopora palifera. Though CAP is diverse, the 16S rRNA phylogeny presents it as a distinct clade separate from other free-living Prosthecochloris. In this study, we build on previous research and further characterize the genomic and metabolic traits of CAP by recovering two new near-complete CAP genomes—Candidatus Prosthecochloris isoporaea and Candidatus Prosthecochloris sp. N1—from coral Isopora palifera endolithic cultures. Genomic analysis revealed that these two CAP genomes have high genomic similarities compared with other Prosthecochloris and harbor several CAP-unique genes. Interestingly, different CAP species harbor various pigment synthesis and sulfur metabolism genes, indicating that individual CAPs can adapt to a diversity of coral microenvironments. A novel near-complete SRB genome—Candidatus Halodesulfovibrio lyudaonia—was also recovered from the same culture. The fact that CAP and various sulfate-reducing bacteria (SRB) co-exist in coral endolithic cultures and coral skeleton highlights the importance of SRB in the coral endolithic community. Based on functional genomic analysis of Ca. P. sp. N1 and Ca. H. lyudaonia, we also propose a syntrophic relationship between the SRB and CAP in the coral skeleton.ImportanceLittle is known about the ecological roles of endolithic microbes in the coral skeleton; one potential role is as a nutrient source for their coral hosts. Here, we identified a close ecological relationship between CAP and SRB. Recovering novel near-complete CAP and SRB genomes from endolithic cultures in this study enabled us to understand the genomic and metabolic features of anaerobic endolithic bacteria in coral skeletons. These results demonstrate that CAP members with similar functions in carbon, sulfur, and nitrogen metabolisms harbor different light-harvesting components, suggesting that CAP in the skeleton adapts to niches with different light intensities. Our study highlights the potential ecological roles of CAP and SRB in coral skeletons and paves the way for future investigations into how coral endolithic communities will respond to environmental changes.

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Photoprotective Role of Endolithic Algae Colonized in Coral Skeleton for the Host Photosynthesis

Photosynthesis. Energy from the Sun ◽

10.1007/978-1-4020-6709-9_300 ◽

2008 ◽

pp. 1391-1395 ◽

Cited By ~ 8

Author(s):

Seitaro S. Yamazaki ◽

Takashi Nakamura ◽

Hideo Yamasaki

Keyword(s):

Coral Skeleton ◽

Endolithic Algae

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Organic matrix synthesis in the scleractinian coral stylophora pistillata: role in biomineralization and potential target of the organotin tributyltin

Journal of Experimental Biology ◽

10.1242/jeb.201.13.2001 ◽

1998 ◽

Vol 201 (13) ◽

pp. 2001-2009 ◽

Cited By ~ 2

Author(s):

D Allemand ◽

É Tambutté ◽

JP Girard ◽

J Jaubert

Keyword(s):

Protein Synthesis ◽

Aspartic Acid ◽

Scleractinian Coral ◽

Organic Matrix ◽

Coral Skeleton ◽

Matrix Proteins ◽

Coral Tissue ◽

Lag Phase ◽

Acid Uptake ◽

Stylophora Pistillata

The kinetics of organic matrix biosynthesis and incorporation into scleractinian coral skeleton was studied using microcolonies of Stylophora pistillata. [14C]Aspartic acid was used to label the organic matrix since this acidic amino acid can represent up to 50 mol % of organic matrix proteins. External aspartate was rapidly incorporated into tissue protein without any detectable lag phase, suggesting either a small intracellular pool of aspartic acid or a pool with a fast turn-over rate. The incorporation of 14C-labelled macromolecules into the skeleton was linear over time, after an initial delay of 20 min. Rates of calcification, measured by the incorporation of 45Ca into the skeleton, and of organic matrix biosynthesis and incorporation into the skeleton were constant. Inhibition of calcification by the Ca2+ channel inhibitor verapamil reduced the incorporation of organic matrix proteins into the skeleton. Similarly, organic matrix incorporation into the skeleton, but not protein synthesis for incorporation into the tissue compartment, was dependent on the state of polymerization of both actin and tubulin, as shown by the sensitivity of this process to cytochalasin B and colchicin. These drugs may inhibit exocytosis of organic matrix proteins into the subcalicoblastic space. Finally, inhibition of protein synthesis by emetin or cycloheximide and inhibition of N-glycosylation by tunicamycin reduced both the incorporation of macromolecules into the skeleton and the rate of calcification. This suggests that organic matrix biosynthesis and its migration towards the site of calcification may be a prerequisite step in the calcification process. On the basis of these results, we investigated the effects of tributyltin (TBT), a component of antifouling painting known to interfere with biomineralization processes. Our results have shown that this xenobiotic significantly inhibits protein synthesis and the subsequent incorporation of protein into coral skeleton. This effect was correlated with a reduction in the rate of calcification. Protein synthesis was shown to be the parameter most sensitive to TBT (IC50=0.2 micromol l-1), followed by aspartic acid uptake by coral tissue (IC50=0.6 micromol l-1), skeletogenesis (IC50=3 micromol l-1) and Ca2+ uptake by coral tissue (IC50=20 micromol l-1). These results suggest that the mode of action of TBT on calcification may be the inhibition of organic matrix biosynthesis.

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Serpulidae (Annelida: Polychaeta) from Hong Kong

Zootaxa ◽

10.11646/zootaxa.3424.1.1 ◽

2012 ◽

Vol 3424 (1) ◽

pp. 1 ◽

Cited By ~ 6

Author(s):

YANAN SUN ◽

HARRY A. TEN HOVE ◽

JIAN-WEN QIU

Keyword(s):

Hong Kong ◽

Benthic Communities ◽

Coral Community ◽

Fish Farm ◽

High Density ◽

Identification Key ◽

Coral Skeleton ◽

Habitat Distribution ◽

Present Material ◽

Dead Coral

Serpulidae (Sabellida, Annelida) is a large group of sedentary polychaetes that live in the calcareous tubes they secrete.In addition to being an important component of marine hard-bottom benthic communities, serpulids include several eco-nomically important invasive and/or fouling species. In this paper we describe the serpulids from Hong Kong, based onspecimens collected from a coral community, a fish farm, a public pier and a shipping channel. Seventeen serpulid taxabelonging to five genera are recorded. The most diverse genus in the present material is Hydroides (9 species), followedby Spirobranchus (5 taxa). The highest diversity (13 taxa) is found on dead coral skeleton. One species, Spirobranchustetraceros, is associated with live corals in high density. For each taxon, the habitat, distribution and morphological fea-tures are described. Including literature records, 20 taxa of serpulids have been reported from Hong Kong. An identification key to all these recorded taxa is provided.

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Reviews and syntheses: Revisiting the boron systematics of aragonite and their application to coral calcification

Biogeosciences ◽

10.5194/bg-15-2819-2018 ◽

2018 ◽

Vol 15 (9) ◽

pp. 2819-2834 ◽

Cited By ~ 9

Author(s):

Thomas M. DeCarlo ◽

Michael Holcomb ◽

Malcolm T. McCulloch

Keyword(s):

Partition Coefficient ◽

Isotopic Fractionation ◽

Computer Code ◽

Comprehensive Analysis ◽

Coral Skeleton ◽

Carbonate Chemistry ◽

Carbonate System ◽

Coral Skeletons ◽

User Friendly ◽

Propagation Of Uncertainties

Abstract. The isotopic and elemental systematics of boron in aragonitic coral skeletons have recently been developed as a proxy for the carbonate chemistry of the coral extracellular calcifying fluid. With knowledge of the boron isotopic fractionation in seawater and the B∕Ca partition coefficient (KD) between aragonite and seawater, measurements of coral skeleton δ11B and B∕Ca can potentially constrain the full carbonate system. Two sets of abiogenic aragonite precipitation experiments designed to quantify KD have recently made possible the application of this proxy system. However, while different KD formulations have been proposed, there has not yet been a comprehensive analysis that considers both experimental datasets and explores the implications for interpreting coral skeletons. Here, we evaluate four potential KD formulations: three previously presented in the literature and one newly developed. We assess how well each formulation reconstructs the known fluid carbonate chemistry from the abiogenic experiments, and we evaluate the implications for deriving the carbonate chemistry of coral calcifying fluid. Three of the KD formulations performed similarly when applied to abiogenic aragonites precipitated from seawater and to coral skeletons. Critically, we find that some uncertainty remains in understanding the mechanism of boron elemental partitioning between aragonite and seawater, and addressing this question should be a target of additional abiogenic precipitation experiments. Despite this, boron systematics can already be applied to quantify the coral calcifying fluid carbonate system, although uncertainties associated with the proxy system should be carefully considered for each application. Finally, we present a user-friendly computer code that calculates coral calcifying fluid carbonate chemistry, including propagation of uncertainties, given inputs of boron systematics measured in coral skeleton.

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