Morphological study of fibrous aragonite in the skeletal framework of a stony coral

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mikihiro Sugiura ◽  
Ko Yasumoto ◽  
Mariko Iijima ◽  
Yuya Oaki ◽  
Hiroaki Imai
Keyword(s):  
Morphological Study ◽  
Stony Coral ◽  
Acropora Digitifera ◽  
Stony Corals ◽  
Crystalline Core ◽  
Low Crystalline

Calcareous skeletons of stony corals are composed of a low-crystalline core (center of calcification: COC) and surrounding fibrous crystals. We characterized the total framework of juvenile Acropora digitifera corals to...

scholarly journals Presence–absence polymorphisms of single-copy genes in the stony coral Acropora digitifera

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Shiho Takahashi-Kariyazono ◽  
Kazuhiko Sakai ◽  
Yohey Terai
Keyword(s):  
Single Copy ◽  
Stony Coral ◽  
Acropora Digitifera

Amorphous/low-crystalline core/shell-type nanoparticles as highly efficient and self-stabilizing catalysts for alkaline hydrogen evolution

2020 ◽  
Vol 56 (63) ◽  
pp. 8984-8987
Author(s):  
Yanfang Wu ◽  
Ming Zhao ◽  
Jing-Pei Cao ◽  
Jing Xu ◽  
Tienan Jin ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Core Shell ◽  
Highly Efficient ◽  
Shell Type ◽  
Crystalline Core ◽  
Low Crystalline

Core/shell-type NPs were fabricated with a low-crystalline Pt–Ni shell as an efficient and self-stabilizing HER catalyst.

scholarly journals COMPOSICIÓN DE LAS COMUNIDADES DE OCTOCORALES Y CORALES PÉTREOS Y LA INCIDENCIA DEL BLANQUEAMIENTO DEL 2005 EN JARDINES DE LA REINA, CUBA

2011 ◽  
Vol 3 ◽  
pp. 77 ◽  
Author(s):  
Leslie Hernández Fernández ◽  
Mayrene Guimarais Bermejo ◽  
Rodolfo Arias Barreto ◽  
Lídice Clero Alonso
Keyword(s):  
Benthic Communities ◽  
Management Plan ◽  
Coral Community ◽  
Porites Astreoides ◽  
Stony Coral ◽  
Stony Corals ◽  
Montastraea Annularis ◽  
Coral Communities ◽  
The Caribbean ◽  
Pseudopterogorgia Americana

En los años 2001 y 2005, se estudió la composición de las comunidades de octocorales y corales pétreos en el archipiélago de los Jardines de la Reina. Se analizó, en la comunidad de corales pétreos, la incidencia del blanqueamiento ocurrido en el 2005 en el Caribe. Para ello se establecieron doce estaciones de muestreo (siete en el arrecife frontal somero y cinco en el arrecife de cresta), en cada una de estas se estimó la densidad mediante el marco cuadrado de 1 m de lado. En el arrecife frontal somero se identificaron un total de 62 especies (26 de octocorales y 36 de corales), siendo las más abundantes: Pseudopterogorgia americana (2.4 colonias/m2), Eunicea flexuosa (1.1 colonias/m2), Siderastrea siderea (5.0 colonias/m2) y Agaricia agaricites (4.0 colonias/m2). En el arrecife de cresta se identificaron un total de 31 especies (13 de octocorales y 18 de corales), predominando: Briareum asbestinum (1.3 colonias/m2), Porites astreoides (2.5 colonias/m2) y Millepora complanata (1.0 colonias/m2). Las especies más sensibles al blanqueamiento fueron: A. agaricites , Millepora spp. y Montastraea annularis. En sentido general, dicho suceso tuvo una incidencia pobre sobre los corales pétreos. Es menester la ejecución de monitoreos al permitir ajustar los planes de manejo en función de los cambios que puedan ocurrir en la estructura de las comunidades bentónicas.ABSTRACT Octocoral and stony coral communities in the Jardines de la Reina archipelago (Cuba) were studied in 2001 and again in 2005. The incidence of the 2005 bleaching event in the Caribbean was analyzed in the stony coral community. Twelve sampling stations were established: seven in the shallow forereef and five in reef crests, with one square meter quadrants to estimate density. A total of 62 species (26 octocorals and 36 stony corals) were identified in the shallow forereef, including Pseudopterogorgia americana (2.4 colonies/m2), Eunicea flexuosa (1.1 colonies/m2), Siderastrea siderea (5.0 colonies/m2) and Agaricia agaricites (4.0 colonies/m2). In the reef crest, 31 species were identified (13 octocorals and 18 stony corals), with Briareum asbestinum (1.3 colonies/m2), Porites astreoides (2.5 colonies/m2) and Millepora complanata (1.0 colonies/m2) being the most abundant. The most sensitive species to bleaching were: A. agaricites, Millepora spp. and Montastraea annulariS. In general, this event showed a poor incidence with stony corals. Constant monitoring is necessary to adjust the management plan to the changes that may occur in the structure of the benthic communities.

scholarly journals Decline in coral cover and flattening of the reefs around Mauritius (1998–2010)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6014 ◽  
Author(s):  
Jennifer A. Elliott ◽  
Mark R. Patterson ◽  
Caroline G. Staub ◽  
Meera Koonjul ◽  
Stephen M. Elliott
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Habitat Complexity ◽  
Human Population ◽  
Coral Cover ◽  
Local Factor ◽  
Stony Coral ◽  
Anthropogenic Stressors ◽  
Global Factor ◽  
Stony Corals

Coral reefs are degrading through the impacts of multiple anthropogenic stressors. How are coral reef communities going to change and how to protect them for future generations are important conservation questions. Using coral reef data from Mauritius, we examined changes in cover in 23 benthic groups for a 13-yr period and at 15 sites. Moreover, we determined which land-based stressor out of four (human population, agriculture, tourism, rainfall) correlated the most with the observed changes in coral reef cover. Among the stony corals, Acropora corals appeared to be the most impacted, decreasing in cover at many sites. However, the non-Acropora encrusting group increased in cover at several sites. The increase in abundance of dead corals and rubble at some sites also supported the observations of stony coral decline during the study period. Additionally, the decline in stony corals appeared to be more pronounced in second half of the study period for all sites suggesting that a global factor rather than a local factor was responsible for this decline. There was little change in cover for the other benthic groups, some of which were quite rare. Human population was significantly correlated with changes in coral reef cover for 11 sites, followed by tourism and agriculture. Rainfall, a proxy for runoff, did not appear to affect coral reef cover. Overall, our results showed that there has been a decline of stony coral cover especially the ones with complex morphologies, which in turn suggest that coral reefs around Mauritius have experienced a decline in habitat complexity during the study period. Our study also suggests that humans are an important factor contributing to the demise of coral reefs around the island.

scholarly journals Discovery of a receptor guanylate cyclase expressed in the sperm flagella of stony corals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yan Zhang ◽  
Yi-Ling Chiu ◽  
Chieh-Jhen Chen ◽  
Yu-Ying Ho ◽  
Chuya Shinzato ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Guanylate Cyclase ◽  
Environmental Cues ◽  
Stony Coral ◽  
Stony Corals ◽  
Basal Metazoan ◽  
Transcriptome Database ◽  
Immunohistochemical Analyses

Abstract The receptor guanylate cyclases (rGCs) in animals serve as sensitive chemoreceptors to detect both chemical and environmental cues. In reproduction, rGCs were shown to be expressed on sperm and serve as receptors for egg-derived sperm-activating and sperm-attracting factors in some echinoderms and mammals. However, sperm-associated rGCs have only been identified in some deuterostomes thus far, and it remains unclear how widely rGCs are utilized in metazoan reproduction. To address this issue, this study investigated the existence and expression of rGCs, particularly asking if rGCs are involved in the reproduction of a basal metazoan, phylum Cnidaria, using the stony coral Euphyllia ancora. Six paralogous rGCs were identified from a transcriptome database of E. ancora, and one of the rGCs, GC-A, was shown to be specifically expressed in the testis. Immunohistochemical analyses demonstrated that E. ancora GC-A protein was expressed in the spermatocytes and spermatids and eventually congregated on the sperm flagella during spermatogenesis. These findings suggest that GC-A may be involved in the regulation of sperm activity and/or functions (e.g., fertilization) in corals. This study is the first to perform molecular characterization of rGCs in cnidarians and provides evidence for the possible involvement of rGCs in the reproduction of basal metazoans.

scholarly journals The calcifying interface in a stony coral's primary polyp: An interplay between seawater and an extracellular calcifying space

2021 ◽  
Author(s):  
Gal Mor Khalifa ◽  
Shani Levy ◽  
Tali Mass
Keyword(s):  
Single Cell ◽  
Rna Seq ◽  
Reef Management ◽  
Stylophora Pistillata ◽  
Stony Coral ◽  
Stony Corals ◽  
Coral Reef Management ◽  
And Function ◽  
Geochemical Studies

Stony coral exoskeletons build the foundation to the most biologically diverse yet fragile marine ecosystems on earth, coral reefs. Understanding corals biomineralization mechanisms is therefore crucial for coral reef management and for using coral skeletons in geochemical studies. In this study, we combine in vivo and cryo-electron microscopy with single cell RNA-seq data to gain novel insights into the calcifying micro environment that facilitates biomineralization in primary polyps of the stony coral Stylophora pistillata. We show an intimate involvement of seawater in this micro environment. We further document increased tissue permeability and a highly dispersed cell packing in the tissue secreting the coral skeleton (i.e. calicoblastic). We also observe an extensive filopodial network containing carbon-rich vesicles extruding from some of the calicoblastic cells. Single cell RNA-Seq data interrogation shows that calicoblastic cells express genes involved in filopodia and vesicle structure and function. These observations provide a new conceptual framework for resolving stony corals biomineralization processes.

scholarly journals Comparative analysis of the genomes of Stylophora pistillata and Acropora digitifera provides evidence for extensive differences between species of corals

2017 ◽  
Author(s):  
Christian R Voolstra ◽  
Yong Li ◽  
Yi Jin Liew ◽  
Sebastian Baumgarten ◽  
Didier Zoccola ◽  
...  
Keyword(s):  
Climate Change ◽  
Evolutionary Divergence ◽  
Fine Scale ◽  
Stylophora Pistillata ◽  
The Core ◽  
Acropora Digitifera ◽  
Stony Corals ◽  
Core Set ◽  
Algal Symbiosis ◽  
Coral Reef Ecosystems

Stony corals form the foundation of coral reef ecosystems. Their phylogeny is characterized by a deep evolutionary divergence that separates corals into a robust and complex clade dating back to at least 245 mya. However, the genomic consequences and clade-specific evolution remain unexplored. In this study we have produced the genome of a robust coral, Stylophora pistillata, and compared it to the available genome of a complex coral, Acropora digitifera. We conducted a fine-scale gene-based analysis focusing on ortholog groups. Among the core set of conserved proteins, we found an emphasis on processes related to the cnidarian-dinoflagellate symbiosis. Similarly, genes associated with the algal symbiosis were also independently expanded in both species, but both corals diverged on the identity of ortholog groups expanded, and we found uneven expansions in genes associated with innate immunity and stress response. Our analyses demonstrate that coral genomes can be surprisingly disparate. Importantly, if the patterns elucidated here are representative of differences between corals from the robust and complex clade, the ability of a coral to respond to climate change may be dependent on its clade association.

Techniques for preparing the Lolium perenne coleorhiza for scanning electron microscope evaluation

1992 ◽  
Vol 50 (1) ◽  
pp. 766-767
Author(s):  
Susan B.G. Debaene ◽  
John S. Gardner ◽  
Phil S. Allen
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Lolium Perenne ◽  
Morphological Study ◽  
Root Hairs ◽  
Inner Pressure ◽  
Water Potentials ◽  
Radicle Emergence ◽  
Standard Fixation ◽  
Scanning Electron

The coleorhiza is a nonvascular sheath that encloses the embryonic radicle in Poaceae, and is generally the first tissue to emerge during germination. Delicate hairlike extensions develop from some coleorhiza cells prior to radicle emergence. Similar to root hairs, coleorhiza hairs are extremely sensitive to desiccation and are damaged by exposure to negative water potentials. The coleorhiza of Lolium perenne is somewhat spherical when first visible, after which a knob forms at a right angle to the caryopsis due to inner pressure from the elongating radicle. This knob increases in length until the radicle finally punctures the coleorhiza. Standard fixation procedures cause severe desiccation of coleorhiza cells and hairs, making morphological study of the coleorhiza difficult. This study was conducted to determine a more successful process for coleorhiza preservation.

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