scholarly journals Environmentally-Driven Variation in the Physiology of a New Caledonian Reef Coral

Oceans ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 15-29
Author(s):  
Anderson B. Mayfield ◽  
Alexandra C. Dempsey
Keyword(s):  
New Caledonia ◽  
Environmental Gradients ◽  
Reef Coral ◽  
Environmental Parameters ◽  
Climate Change Impacts ◽  
Diel Variation ◽  
Pocillopora Damicornis ◽  
Molecular Physiology ◽  
Know How ◽  
Basic Biology

Given the widespread threats to coral reefs, scientists have lost the opportunity to understand the basic biology of “pristine” corals whose physiologies have not been markedly perturbed by human activity. For instance, high temperature-induced bleaching has been occurring annually since 2014 in New Caledonia. Because most corals cannot withstand repeated years when bleaching occurs, an analysis was undertaken to showcase coral behavior in a period just before the onset of “annual severe bleaching” (ASB; November 2013) such that future generations might know how these corals functioned in their last bleaching-free year. Pocillopora damicornis colonies were sampled across a variety of environmental gradients, and a subset was sampled during both day and night to understand how their molecular biology changes upon cessation of dinoflagellate photosynthesis. Of the 13 environmental parameters tested, sampling time (i.e., light) most significantly affected coral molecular physiology, and expression levels of a number of both host and Symbiodiniaceae genes demonstrated significant diel variation; endosymbiont mRNA expression was more temporally variable than that of their anthozoan hosts. Furthermore, expression of all stress-targeted genes in both eukaryotic compartments of the holobiont was high, even in isolated, uninhabited, federally protected atolls of the country’s far northwest. Whether this degree of sub-cellular stress reflects cumulative climate change impacts or, instead, a stress-hardened phenotype, will be unveiled through assessing the fates of these corals in the wake of increasingly frequent marine heatwaves.

scholarly journals Subcellular Investigation of Photosynthesis-Driven Carbon Assimilation in the Symbiotic Reef Coral Pocillopora damicornis

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Christophe Kopp ◽  
Isabelle Domart-Coulon ◽  
Stephane Escrig ◽  
Bruno M. Humbel ◽  
Michel Hignette ◽  
...  
Keyword(s):  
Lipid Droplets ◽  
Secondary Ion Mass Spectrometry ◽  
Reef Coral ◽  
Carbon Assimilation ◽  
Isotopic Labeling ◽  
Cellular Level ◽  
Coral Tissue ◽  
Pocillopora Damicornis ◽  
Carbon And Nitrogen ◽  
Transmission Electron

ABSTRACT  Reef-building corals form essential, mutualistic endosymbiotic associations with photosynthetic Symbiodinium dinoflagellates, providing their animal host partner with photosynthetically derived nutrients that allow the coral to thrive in oligotrophic waters. However, little is known about the dynamics of these nutritional interactions at the (sub)cellular level. Here, we visualize with submicrometer spatial resolution the carbon and nitrogen fluxes in the intact coral-dinoflagellate association from the reef coral Pocillopora damicornis by combining nanoscale secondary ion mass spectrometry (NanoSIMS) and transmission electron microscopy with pulse-chase isotopic labeling using [13C]bicarbonate and [15N]nitrate. This allows us to observe that (i) through light-driven photosynthesis, dinoflagellates rapidly assimilate inorganic bicarbonate and nitrate, temporarily storing carbon within lipid droplets and starch granules for remobilization in nighttime, along with carbon and nitrogen incorporation into other subcellular compartments for dinoflagellate growth and maintenance, (ii) carbon-containing photosynthates are translocated to all four coral tissue layers, where they accumulate after only 15 min in coral lipid droplets from the oral gastroderm and within 6 h in glycogen granules from the oral epiderm, and (iii) the translocation of nitrogen-containing photosynthates is delayed by 3 h. IMPORTANCE  Our results provide detailed in situ subcellular visualization of the fate of photosynthesis-derived carbon and nitrogen in the coral-dinoflagellate endosymbiosis. We directly demonstrate that lipid droplets and glycogen granules in the coral tissue are sinks for translocated carbon photosynthates by dinoflagellates and confirm their key role in the trophic interactions within the coral-dinoflagellate association.

scholarly journals TIMING OF LARVAL RELEASE BY REEF CORAL Pocillopora damicornis AT PANJANG ISLAND, CENTRAL JAVA

2018 ◽  
Vol 33 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Munasik ◽  
Suharsono ◽  
J. Situmorang ◽  
H. N. Kamiso
Keyword(s):  
Full Moon ◽  
Reef Coral ◽  
Lunar Cycle ◽  
Tidal Range ◽  
Pocillopora Damicornis ◽  
Larval Release ◽  
Double Peaks ◽  
Central Java ◽  
New Moon ◽  
Peak Release

Monthly larval release by the coral Pocillopora damicornis at Panjang Island, Central Java was investigated. Corals were collected from windward and leeward and maintained in outdoor, flow-trough system to quantify nightly release of larvae. Larval release of the coral occurs every month throughout the year, and its planulation increased during dry monsoon. Monthly planulation occurs from new moon to full moon and possesses in different pattern between single and paired colonies. Planulation in paired colonies occurred in single peak and more synchronized in each colony however single colonies planulated in double peaks and less synchronized in each colony. This study confirmed that planulation period of P. damicornis at Panjang Island over a range of lunar phases with shorter periods of peak release which predominantly controlling by tidal range rather than lunar cycle.

scholarly journals Lokale Anpassung bei Waldbaumarten: genetische Prozesse und Bedeutung im Klimawandel

2016 ◽  
Vol 167 (6) ◽  
pp. 333-340
Author(s):  
Christian Rellstab ◽  
Andrea R. Pluess ◽  
Felix Gugerli
Keyword(s):  
Local Adaptation ◽  
Environmental Gradients ◽  
Management Strategies ◽  
Environmental Parameters ◽  
Forest Trees ◽  
Local Conditions ◽  
Genetic Changes ◽  
Association Analyses ◽  
Temperature And Precipitation ◽  
Technological Advances

Local adaptation in forest trees: genetic processes and relevance under climate change Forest trees will have to adapt to future climatic changes, a process that will comprise genetic changes as a key component. Owing to technological advances it is now possible to identify the signature of natural selection and local adaptation in the genome. Environmental association analyses aim at associating adaptive genetic patterns with environmental parameters describing the local habitat. On the basis of such studies – including own investigations using oak and beech in Switzerland –, we show that forest trees are genetically differentiated along various environmental gradients, especially temperature and precipitation. Numerous genes could be found that presumably play a role in the adaptation to such environmental factors. Based on these findings, one could identify trees or stands that are adapted to future local conditions, and respective seed material could be considered in silviculture. Because such approaches are still in their infancy and because genome-environment interactions are complex, management strategies should focus on the preservation of (adaptive) genetic diversity, natural regeneration, and connectivity among stands. This would set the basis for the local adaptation of forest stands to altered environmental conditions by natural processes.

Skeletal Organization in the Coral, Pocillopora Damicornis

1963 ◽  
Vol s3-104 (66) ◽  
pp. 169-183
Author(s):  
STEPHEN A. WAINWRIGHT
Keyword(s):  
Reef Coral ◽  
Average Diameter ◽  
Mineral Deposit ◽  
Amide Group ◽  
Total Weight ◽  
Organic Substrates ◽  
Pocillopora Damicornis ◽  
Chitin Synthesis ◽  
Larval Skeleton ◽  
Initial Mineral

The skeleton of this Hawaiian reef coral was found to contain at least 99.9% by weight of the mineral aragonite, present as submicroscopic crystals in spheritic arrangements. The organic component of the skeleton comprises 0.01 to 0.1% of the total weight and has 3 microscopic constituents: (1) filaments of lime-boring algae, (2) a dispersed network of fibres 1 µ in diameter, and (3) a transparent, milky, regionally birefringent matrix of chitin. The chitin was observed to be a spongework of fibrils of average diameter 20 mµ. The chitin fibrils were inferred to be randomly oriented in the plane of the skeletogenic epithelium perpendicular to the direction of growth of the long axes of the aragonite crystals. The development of the skeleton is traced from the initial mineral deposit by the larva after its attachment, through the formation of the larval skeleton and growth into the fully formed, branching colony. The process of formation of chitin fibrils according to the contour of the skeletogenic epithelium and the later deposition of aragonite crystals as described accounts for the formation of all skeletal elements of Pocillopora. Evidence is presented for the hypotheses that (1) the amide group of the chitin molecule is responsible for the ability of certain organic substrates to be calcified (thus protein is not a necessary component of such substrates); (2) zooxanthellae in Pocillopora contribute a product of photosynthesis to the coral as the monomer of the chitin matrix; and (3) chitin synthesis thus depends on the activity of zooxanthellae and the rate of chitin synthesis controls the rate of skeletogenesis in Pocillopora.

Wet meadows of the alliance Molinion and their environmental gradients in Slovenia

Biologia ◽  
2008 ◽  
Vol 63 (2) ◽  
Author(s):  
Igor Zelnik ◽  
Andraž Čarni
Keyword(s):  
Plant Communities ◽  
Environmental Gradients ◽  
Environmental Parameters ◽  
Nutrient Status ◽  
Soil Parameters ◽  
Soil Reaction ◽  
Mean Annual Temperature ◽  
Wet Meadow ◽  
Organic C ◽  
Temperature And Precipitation

AbstractThe main objective of this study was to examine the relationships between wet meadow plant communities of Molinon alliance and their environmental conditions in Slovenia. The ecology of these communities was analysed in detail. The study provides the data on the vegetation and environmental parameters, the significance of parameters for the plant species composition, most important environmental gradients and differences between plant communities. In all plots the vegetation was recorded and soil parameters were analysed (pH, plant-available P and K, Nt, organic C, C/N ratio, exchangeable Ca2+, Mg2+, K+, Na+, H+, electrical conductivity, base saturation). Other conditions were also considered (e.g., mean annual temperature and precipitation, humidity index, mean Ellenberg moisture and nutrient value) to test possible correlations as well. Vegetation was classified by means of multivariate cluster analysis, while vegetation-site relationships were examined with direct gradient analysis (CCA). Six associations from the Molinon alliance (Selino-Molinietum, Plantagini altissimae-Molinietum, Carici davallianae-Molinietum, Gentiano-Molinietum litoralis, Junco conglomerati-Betonicetum and Sanguisorbo-Festucetum commutatae) were identified and analysed. Soil reaction was identified as most significant environmental parameter explaining the variation of the studied vegetation. There are several statistically significant differences in site conditions between the communities (pH, moisture, nutrient status, Ca2+). The studied associations represent clearly defined ecological units.

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