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Tamar L. Goulet - One of the best experts on this subject based on the ideXlab platform.
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Lesion recovery and the bacterial microbiome in two Caribbean Gorgonian corals
Marine Biology, 2016Co-Authors: Kartick P. Shirur, Colin R. Jackson, Tamar L. GouletAbstract:In the Caribbean, Gorgonian corals dominate many coral reefs, while scleractinian coral cover has declined. Gorgonian corals deal with stressors such as lesions caused by wave action, predation, or human activities. In June 2012, artificial wounds were inflicted on branches of the Gorgonians Eunicea flexuosa and Pseudoplexaura porosa found at 3–5 m depth on a patch reef (20°52′5.23″N, 86°51′58.92″W) near Puerto Morelos, Mexico. Following healing, injured and uninjured branches were collected to determine the effect of lesions on Gorgonian biochemistry, symbiosis, microbiome, and immune response. Lesion recovery in E. flexuosa took twice as long as in P. porosa . In both species, tissues at and surrounding the lesions contained significantly higher sclerite content per dry weight but lower protein per surface area. In and around the lesion area, the density of symbiotic dinoflagellates, Symbiodinium spp., was lower than in uninjured branches, although Symbiodinium photochemical efficiency in tissues surrounding the lesion was not affected. The Gorgonian species differed in their bacterial microbiome, but the overall bacterial community and dominant bacterial taxa did not differ between injured and uninjured branches, although the prevalence of some less common bacterial groups did vary. The two species exhibited distinct immune responses, whereby different components of the melanization cascade were activated, and exochitinase was mobilized only in E. flexuosa . While the Gorgonian species differed in their lesion recovery response, both healed without signs of disease or colonization by fouling organisms. The capacity to recover successfully from injuries may partly explain why Gorgonian corals dominate Caribbean coral reefs.
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Lesion recovery and the bacterial microbiome in two Caribbean Gorgonian corals
Marine Biology, 2016Co-Authors: Kartick P. Shirur, Colin R. Jackson, Tamar L. GouletAbstract:In the Caribbean, Gorgonian corals dominate many coral reefs, while scleractinian coral cover has declined. Gorgonian corals deal with stressors such as lesions caused by wave action, predation, or human activities. In June 2012, artificial wounds were inflicted on branches of the Gorgonians Eunicea flexuosa and Pseudoplexaura porosa found at 3–5 m depth on a patch reef (20°52′5.23″N, 86°51′58.92″W) near Puerto Morelos, Mexico. Following healing, injured and uninjured branches were collected to determine the effect of lesions on Gorgonian biochemistry, symbiosis, microbiome, and immune response. Lesion recovery in E. flexuosa took twice as long as in P. porosa . In both species, tissues at and surrounding the lesions contained significantly higher sclerite content per dry weight but lower protein per surface area. In and around the lesion area, the density of symbiotic dinoflagellates, Symbiodinium spp., was lower than in uninjured branches, although Symbiodinium photochemical efficiency in tissues surrounding the lesion was not affected. The Gorgonian species differed in their bacterial microbiome, but the overall bacterial community and dominant bacterial taxa did not differ between injured and uninjured branches, although the prevalence of some less common bacterial groups did vary. The two species exhibited distinct immune responses, whereby different components of the melanization cascade were activated, and exochitinase was mobilized only in E. flexuosa . While the Gorgonian species differed in their lesion recovery response, both healed without signs of disease or colonization by fouling organisms. The capacity to recover successfully from injuries may partly explain why Gorgonian corals dominate Caribbean coral reefs.
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A maximum likelihood phylogenetic tree based on microsatellite flanking regions of B1 Symbiodinium.
2014Co-Authors: Blake D. Ramsby, Kartick P. Shirur, Roberto Iglesias-prieto, Tamar L. GouletAbstract:The phylogeny includes B1 Symbiodinium from the four Gorgonian species in this study (highlighted in gray), from other Gorgonian corals [47], from scleractinian and hydrozoan corals [36], as well as Symbiodinium minutum from Aiptasia, a sea anemone [47]. Branch tips are labeled with host species and sample sizes when n>1. Gorgonian and scleractinian coral species are shown in black and red, respectively, and the other cnidarians are shown in blue. B1 lineages described by Finney et al. [36] are listed besides the host taxa. Numbers above the branches are the posterior probability above the maximum likelihood consensus support for each group. B1 Symbiodinium from 16 of 19 Gorgonian colonies sampled clustered in a phylogenetic group with high posterior probability (top gray box). Three Gorgonian colonies were placed outside of this clade (bottom gray box) and were most closely related to Symbiodinium isolated from Pseudoplexaura porosa from Florida (indicated with (+1)) and cultured Symbiodinium from Gorgonia ventalina[47] indicated with *. (#) indicates a group recovered in the maximum likelihood tree, but not the Bayesian phylogenetic tree.
Marc Slattery - One of the best experts on this subject based on the ideXlab platform.
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Fungal pathogenesis of the sea fan Gorgonia ventalina: direct and indirect consequences
CHEMOECOLOGY, 1999Co-Authors: Marc SlatteryAbstract:Fungal pathogenesis of the sea fan Gorgonia ventalina has developed on the Belize barrier reef during 1997 and 1998. The disease incidence (= percent of infected sea fans) remained unchanged at two sites along the barrier reef crest between years. However, the incidence increased significantly at an offshore atoll during that time, as did the virulence (= percent tissue loss). Grazing by the Gorgonian specialist mollusc Cyphoma gibbosum increased on infected sea fans. Sea fan responses to fungal infection included significant decreases in a furano-germacrene compound with antifeedant activity and significant increases in the concentration of sclerites at the site of infection. Feeding assays utilizing C. gibbosum and a natural assemblage of reef fishes indicated sclerites are an effective deterrent, to both consumers, at both pre- and post-infected concentrations. In contrast, the compound was only deterrent to the fish, and only at concentrations found in pre-infected sea fans. These data indicate that sea fan pathogenesis can directly and indirectly affect population health via virulent tissue necrosis and pathogen-mediated reductions in grazer resistance, respectively.
Garriet W. Smith - One of the best experts on this subject based on the ideXlab platform.
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Identification of a consistent polyene component of purple pigment in diseased sclerites of Caribbean corals across region, species, and insult agent.
Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2017Co-Authors: Monty L. Fetterolf, Chad L. Leverette, Christopher Perez, Garriet W. SmithAbstract:Gorgonians respond to insult (damage and disease) by producing sclerites containing a purple pigment as opposed to the normal white sclerites. Raman microscopy is used to study the purple areas of three species of diseased coral, Gorgonia ventalina, Pseudoplexaura porosa, and Eunicea laciniata obtained from Puerto Rico. These spectra were compared to Gorgonia ventalina samples previously reported that were obtained from San Salvador, Bahamas. Spectra from two samples of G. ventalina that had been infected by different agents, Aspergillus sydowii and a slime mold, were also obtained. The results indicate that the purple compounds (polyenes) generated by the coral in response to infection are similar regardless of region from which the coral were harvested, of species of coral, and of the infective agent. A discussion of the Raman spectra of G. ventalina and the other coral species is presented.
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Aspergillosis of Gorgonians
Coral Health and Disease, 2004Co-Authors: Garriet W. Smith, Ernesto WeilAbstract:In the 1980s, certain areas in the Caribbean experienced mass mortalities of sea fans (Gorgonia flabellum). These areas included the coasts of Costa Rica (Guzman and Cortez 1984), Panama (Garzon-Ferreira and Zea 1992; Diaz et al. 1995), and Trinidad (Laydoo 1983). Laydoo (1983) suggested that the cause may be due to a species-specific pathogen, but microbiological studies were not performed. Although limited mortalities of Gorgonian colonies were previously observed due to fish grazing (Kinzie 1973), Cyphoma sp. grazing (Harvell and Suchanek 1987), fouling and overgrowth (Wahle 1985) and tumors (Morse et al. 1977, 1981), the 1980’s outbreak showed signs of an epizootic which had spread from the southwestern to the southeastern Caribbean.
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Characterization of Aspergillus sydowii (Thom et Church), a fungal pathogen of Caribbean sea fan corals
The Ecology and Etiology of Newly Emerging Marine Diseases, 2001Co-Authors: Alisa P. Alker, Garriet W. Smith, Kiho KimAbstract:In the Caribbean, the fungus Aspergillus sydowii is currently causing an epizootic among sea fan corals (Gorgonia spp.). To elucidate potential factors that may have facilitated the emergence of this disease, we characterized and compared temperature requirements, susceptibility to coral crude extracts, and metabolic profiles of pathogenic (marine) and non-pathogenic (terrestrial) strains of A. sydowii. Growth of all A. sydowii strains were observed at all temperatures tested (22–36 °C) with an optimum of approximately 30 °C. Sea fan crude extracts inhibited growth of A. sydowii but were less effective at higher temperatures. Thus, temperature is likely to have a strong influence on the dynamics of the Gorgonia–Aspergillus interaction by promoting the growth of the pathogen while reducing the efficacy of host resistance. Metabolically, marine A. sydowii strains pathogenic to sea fans were distinct from non-pathogenic terrestrial strains.
Marilyn L. Fogel - One of the best experts on this subject based on the ideXlab platform.
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Investigating Bermuda's pollution history through stable isotope analyses of modern and museum-held Gorgonian corals.
Marine pollution bulletin, 2016Co-Authors: David M. Baker, Thaddeus J. T. Murdoch, Ie Conti-jerpe, Marilyn L. FogelAbstract:Abstract For centuries, Bermuda has been challenged with wastewater management for the protection of human and environmental health. By quantifying the δ 15 N of the common sea fan Gorgonia ventalina sampled from 30 sites throughout Bermuda we show that sewage-derived nitrogen is detectable on nearshore coral reefs and declines across the lagoon to the outer rim. We also sampled Gorgonians from two museum collections representing a 50y time-series (1958–2008). These samples revealed an increase in δ 15 N of > 4.0‰ until the mid-1970s, after which δ 15 N values slowly declined by ~ 2.0‰. A δ 15 N chronology from a Gorgonian skeleton exhibited a similar decline over the last 30–40 years of approximately 0.6‰. We conclude that policies have been effective in reducing sewage impacts to Bermudian reefs. However, significant sources of sewage pollution persist and are likely have a strong impact on harbor and nearshore coral communities and human health.
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Productivity links morphology, symbiont specificity and bleaching in the evolution of Caribbean octocoral symbioses
The ISME Journal, 2015Co-Authors: David M. Baker, Kiho Kim, Christopher J Freeman, Nancy Knowlton, Robert W Thacker, Marilyn L. FogelAbstract:Many cnidarians host endosymbiotic dinoflagellates from the genus Symbiodinium . It is generally assumed that the symbiosis is mutualistic, where the host benefits from symbiont photosynthesis while providing protection and photosynthetic substrates. Diverse assemblages of symbiotic Gorgonian octocorals can be found in hard bottom communities throughout the Caribbean. While current research has focused on the phylo- and population genetics of Gorgonian symbiont types and their photo-physiology, relatively less work has focused on biogeochemical benefits conferred to the host and how these benefits vary across host species. Here we examine this symbiosis among 11 Gorgonian species collected in Bocas del Toro, Panama. By coupling light and dark bottle incubations (P/R) with ^13C-bicarbonate tracers, we quantified the link between holobiont oxygen metabolism with carbon assimilation and translocation from symbiont to host. Our data show that P/R varied among species, and was correlated with colony morphology and polyp size. Sea fans and sea plumes were net autotrophs (P/R>1.5), while nine species of sea rods were net heterotrophs with most below compensation (P/R
Carlos Toledo-hernández - One of the best experts on this subject based on the ideXlab platform.
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Comparison of chemical compounds associated with sclerites from healthy and diseased sea fan corals (Gorgonia ventalina).
PeerJ, 2017Co-Authors: Carlos Toledo-hernández, Claudia Patricia Ruiz-diaz, Liz M. Díaz-vázquez, Vanessa Santiago-cárdenas, Derick N. Rosario-berrios, Derek M. García-almedina, Loretta M. RobersonAbstract:BACKGROUND The roles of Gorgonian sclerites as structural components and predator deterrents have been widely studied. Yet their role as barriers against microbes has only recently been investigated, and even less is known about the diversity and roles of the chemical compounds associated with sclerites. METHODS Here, we examine the semi-volatile organic compound fraction (SVOCs) associated with sclerites from healthy and diseased Gorgonia ventalina sea fan corals to understand their possible role as a stress response or in defense of infection. We also measured the oxidative potential of compounds from diseased and healthy G. ventalina colonies. RESULTS The results showed that sclerites harbor a great diversity of SVOCs. Overall, 70 compounds were identified, the majority of which are novel with unknown biological roles. The majority of SVOCs identified exhibit multiple immune-related roles including antimicrobial and radical scavenging functions. The free radical activity assays further confirmed the anti-oxidative potential of some these compounds. The anti-oxidative activity was, nonetheless, similar across sclerites regardless of the health condition of the colony, although sclerites from diseased sea fans display slightly higher anti-oxidative activity than the healthy ones. DISCUSSION Sclerites harbor great SVOCs diversity, the majority of which are novel to sea fans or any other corals. Yet the scientific literature consulted showed that the roles of compounds found in sclerites vary from antioxidant to antimicrobial compounds. However, this study fell short in determine the origin of the SVOCs identified, undermining our capacity to determine the biological roles of the SVOCs on sclerites and sea fans.
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Microwave-accelerated processing of coral tissue histology
Journal of Histology and Histopathology, 2014Co-Authors: Carlos Toledo-hernández, Irma Torres-vazquez, Jose L. Serrano-velezAbstract:Background: Microwave technology has revolutionized histological processing by reducing processing time and improving tissue integrity. We describe the first microwave-accelerated tissue processing procedure for healthy and diseased tissue fragments of two species of corals: the Gorgonian Gorgonia ventalina and the scleractinian Acropora cervicornis. Methods: Fourteen tissue samples from sea fans (eleven healthy and three diseased), and one tissue sample from a healthy A. cervicornis, were decalcified and processed using microwaves. Histological slices were stained using hematoxylin and eosin and immunostained using an antibody against Aspergillus. Results: By using microwave technology, the decalcification time, as well as the steps and time for tissue processing were significantly reduced while maintaining the integrity of the tissue. Conclusions: This technique accelerates the chemical processing of coral tissue, while providing high quality and optimal resolution of histological sections.
