scholarly journals Growth Dynamics of the Threatened Caribbean Staghorn Coral Acropora cervicornis: Influence of Host Genotype, Symbiont Identity, Colony Size, and Environmental Setting

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107253 ◽  
Author(s):  
Diego Lirman ◽  
Stephanie Schopmeyer ◽  
Victor Galvan ◽  
Crawford Drury ◽  
Andrew C. Baker ◽  
...  
Keyword(s):  
Colony Size ◽  
Growth Dynamics ◽  
Acropora Cervicornis ◽  
Host Genotype ◽  
Environmental Setting

scholarly journals Outplanting technique, host genotype, and site affect the initial success of outplanted Acropora cervicornis

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4433 ◽  
Author(s):  
Elizabeth A. Goergen ◽  
David S. Gilliam
Keyword(s):  
Colony Size ◽  
Health Condition ◽  
Acropora Cervicornis ◽  
Host Genotype ◽  
Reef Restoration ◽  
Colony Density ◽  
Colony Loss ◽  
One Year ◽  
Colony Survival ◽  
Low Prevalence

Acropora cervicornis is the most widely used coral species for reef restoration in the greater Caribbean. However, outplanting methodologies (e.g., colony density, size, host genotype, and attachment technique) vary greatly, and to date have not been evaluated for optimality across multiple sites. Two experiments were completed during this study, the first evaluated the effects of attachment technique, colony size, and genotype by outplanting 405 A. cervicornis colonies, from ten genotypes, four size classes, and three attachment techniques (epoxy, nail and cable tie, or puck) across three sites. Colony survival, health condition, tissue productivity, and growth were assessed across one year for this experiment. The second experiment assessed the effect of colony density by outplanting colonies in plots of one, four, or 25 corals per 4 m2 across four separate sites. Plot survival and condition were evaluated across two years for this experiment in order to better capture the effect of increasing cover. Colonies attached with a nail and cable tie resulted in the highest survival regardless of colony size. Small corals had the lowest survival, but the greatest productivity. The majority of colony loss was attributed to missing colonies and was highest for pucks and small epoxied colonies. Disease and predation were observed at all sites, but did not affect all genotypes, however due to the overall low prevalence of either condition there were no significant differences found in any comparison. Low density plots had significantly higher survival and significantly lower prevalence of disease, predation, and missing colonies than high density plots. These results indicate that to increase initial outplant success, colonies of many genotypes should be outplanted to multiple sites using a nail and cable tie, in low densities, and with colonies over 15 cm total linear extension.

scholarly journals Growth dynamics in Acropora cervicornis and A. prolifera in southwest Puerto Rico

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8435 ◽  
Author(s):  
Ernesto Weil ◽  
Nicholas M. Hammerman ◽  
Rebecca L. Becicka ◽  
Juan Jose Cruz-Motta
Keyword(s):  
Puerto Rico ◽  
Disease Outbreaks ◽  
Growth Dynamics ◽  
Medium Size ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
Storm Damage ◽  
Quick Recovery ◽  
Natural Reserve ◽  
La Parguera

Natural population recovery of Acropora palmata, A. cervicornis and their hybrid, Acropora prolifera, have fluctuated significantly after their Caribbean-wide, disease-induced mass mortality in the early 1980s. Even though significant recovery has been observed in a few localities, recurrent disease outbreaks, bleaching, storm damage, local environmental deterioration, algae smothering, predation, low sexual recruitment and low survivorship have affected the expected, quick recovery of these weedy species. In this study, the status of three recovering populations of A. cervicornis and two of A. prolifera were assessed over one year using coral growth and mortality metrics, and changes in their associated algae and fish/invertebrate communities in three localities in the La Parguera Natural Reserve (LPNR), southwest coast of Puerto Rico. Five branches were tagged in each of 29, medium size (1–2 m in diameter) A. cervicornis and 18 A. prolifera colonies in the Media Luna, Mario and San Cristobal reefs off LPNR. Branches were measured monthly, together with observations to evaluate associated disease(s), algae accumulation and predation. A. cervicornis grew faster [3.1 ± 0.44 cm/month (= 37.2 cm/y)] compared to A. prolifera [2.6 ± 0.41 cm/month (= 31.2 cm/y)], and growth was significantly higher during Winter-Spring compared to Summer-Fall for both taxa (3.5 ± 0.58 vs. 0.53 ± 0.15 cm/month in A. cervicornis, and 2.43 ± 0.71 vs. 0.27 ± 0.20 cm/month in A. prolifera, respectively). Algal accumulation was only observed in A. cervicornis, and was higher during Spring-Summer compared to Fall-Winter (6.1 ± 0.91 cm/month and 3.8 ± 0.29 cm/month, respectively, (PERMANOVA, df = 2, MS = 10.2, p = 0.37)). Mortality associated with white band disease, algae smothering and fish/invertebrate predation was also higher in A. cervicornis and varied among colonies within sites, across sites and across season. The balance between tissue grow and mortality determines if colonies survive. This balance seems to be pushed to the high mortality side often by increasing frequency of high thermal anomalies, inducing bleaching and disease outbreaks and other factors, which have historically impacted the natural recovery of these taxa in the La Parguera Natural Reserve in Puerto Rico and possibly other areas in the region. Overall, results indicate variability in both growth and mortality rates in both taxa across localities and seasons, with A. cervicornis showing overall higher mortalities compared to A. prolifera.

scholarly journals Host-specific epibiomes of distinct Acropora cervicornis genotypes persist after field transplantation

2021 ◽  
Author(s):  
Emily G Aguirre ◽  
Wyatt MIllion ◽  
Erich Bartels ◽  
Cory Krediet ◽  
Carly D Kenkel
Keyword(s):  
Common Garden ◽  
Florida Keys ◽  
Amplicon Sequencing ◽  
Acropora Cervicornis ◽  
Host Genotype ◽  
Microbial Composition ◽  
Coral Mucus ◽  
Reef Restoration ◽  
16S Rrna Amplicon Sequencing ◽  
One Year

Microbiome studies across taxa have established the influence of host genotype on microbial recruitment and maintenance. However, research exploring host-specific epibionts in scleractinian corals is scant and the influence of intraspecific differences across environments remains unclear. Here, we studied the epibiome of ten Acropora cervicornis genotypes to investigate the relative roles of host genotype and environment in structuring the epibiome. Coral mucus was sampled in a common garden nursery from replicate ramets of distinct genotypes (T0). Coral fragment replicates (n=3) of each genotype were then transplanted to nine different field sites in the Lower Florida Keys and mucus was again sampled one year later from surviving ramets (T12). 16S rRNA amplicon sequencing was used to assess microbial composition, richness, and beta-diversity. The most abundant and consistent amplicon sequencing variants (ASVs) in all samples belonged to Fokiniaceae (MD3-55 genus) and Cyanobacteria (Synechococccus). The abundances of these bacterial taxa varied consistently between genotypes whereas neither the composition nor taxonomic abundance were significantly different among field sites. Interestingly, several high MD3-55 hosting genotypes showed rapid diversification and an increase in MD3-55 following transplantation. Overall, our results indicate healthy A. cervicornis genotypes retain distinct epibiome signatures through time, suggesting a strong host component. Lastly, our results show that differences in MD3-55 abundances can be consistently detected in the epibiome of distinct host-genotypes of A. cervicornis. As this organism (sensu Aquarickettsia rohweri) has been implicated as a marker of disease resistance, this finding reinforces the potential use of microbial indicators in reef restoration efforts via non-invasive surface/mucus sampling.

scholarly journals Quantification of within patient Staphylococcus aureus phenotypic heterogeneity as a proxy for presence of persisters across clinical presentations

2021 ◽  
Author(s):  
Julian Baer ◽  
Mathilde Boumasmoud ◽  
Srikanth Mairpady Shambat ◽  
Cl&eacutement Vulin ◽  
Markus Huemer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Colony Size ◽  
Genetic Resistance ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Colony Growth ◽  
Phenotypic Heterogeneity ◽  
Growth Delay ◽  
Size Heterogeneity

Background: Difficult-to-treat infections caused by antibiotic susceptible strains have been linked with the occurrence of persisters. Persisters are a subpopulation of dormant bacteria that tolerate antibiotic exposure despite lacking genetic resistance. They can be identified phenotypically upon plating on nutrient agar because of their altered growth dynamics, resulting in colony size heterogeneity. The occurrence of within-patient bacterial phenotypic heterogeneity in various infections and clinical determinants of persister formation remain unknown. Methods: We plated bacteria derived from 132 patient-samples of difficult-to-treat infections directly on nutrient-rich agar and monitored colony growth by time lapse imaging. Of these, we retained 36 Staphylococcus aureus mono-cultures for further analysis. We investigated clinical factors potentially associated with increased colony growth-delay with regression analyses. Additionally, we corroborated the clinical findings using in vitro grown static biofilms, exposed to distinct antibiotics. Results: The extent of phenotypic heterogeneity of patient-derived S. aureus varied substantially between patients. Increased heterogeneity coincided with increased median growth-delay. Multivariable regression showed that rifampicin treatment was significantly associated with increased median growth-delay. S. aureus grown in biofilms and exposed to high concentrations of rifampicin or a combination of rifampicin with either clindamycin or levofloxacin exhibited prolonged growth-delay, correlating with a strain-dependent increase in antibiotic tolerance. Conclusion: Upon direct cultivation on nutrient-rich agar, S. aureus from difficult to treat infections commonly exhibited colony size heterogeneity. This was due to heterogeneous delays in growth resumption, with delays larger than two days in the most extreme cases. Since bacteria in a dormant state are tolerant to antibiotics, the observation of large growth-delays might have direct clinical implications. Future studies are needed to assess the potential of bacterial phenotypic heterogeneity quantification for staphylococcal infections prognosis.

Cristal-growth dynamics of n-doped gaAs

1992 ◽  
Vol 50 (2) ◽  
pp. 1544-1545
Author(s):  
Pham V. Huong ◽  
Stéphanie Bouchet ◽  
Jean-Claude Launay
Keyword(s):  
Crystal Growth ◽  
Spatial Resolution ◽  
Epitaxial Layer ◽  
Outer Surface ◽  
Gaas Substrate ◽  
Structural Modification ◽  
Growth Dynamics ◽  
Argon Laser ◽  
High Anisotropy ◽  
Crystal Gaas

Microstructure of epitaxial layers of doped GaAs and its crystal growth dynamics on single crystal GaAs substrate were studied by Raman microspectroscopy with a Dilor OMARS instrument equipped with a 1024 photodiode multichannel detector and a ion-argon laser Spectra-Physics emitting at 514.5 nm.The spatial resolution of this technique, less than 1 μm2, allows the recording of Raman spectra at several spots in function of thickness, from the substrate to the outer deposit, including areas around the interface (Fig.l).The high anisotropy of the LO and TO Raman bands is indicative of the orientation of the epitaxial layer as well as of the structural modification in the deposit and in the substrate at the interface.With Sn doped, the epitaxial layer also presents plasmon in Raman scattering. This fact is already very well known, but we additionally observed that its frequency increases with the thickness of the deposit. For a sample with electron density 1020 cm-3, the plasmon L+ appears at 930 and 790 cm-1 near the outer surface.

Contrasting whisker growth dynamics within the phocid lineage

2020 ◽  
Vol 634 ◽  
pp. 231-236 ◽  
Author(s):  
EA McHuron ◽  
T Williams ◽  
DP Costa ◽  
C Reichmuth
Keyword(s):  
Whisker Growth ◽  
Growth Dynamics
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