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1.
  • 1. When considering widely distributed marine organisms with low dispersal capabilities, there is often an implication that the distribution of cosmopolitan species is an artefact of taxonomy, constrained by the absence of characters for delimiting either sibling or cryptic species. Few studies have assessed the relationship among populations across the global range of the species' distribution, and the presence of oceanographic barriers that might influence gene flow among populations are underestimated.
  • 2. In this study, evolutionary and ecological drivers of connectivity patterns have been inferred among populations of the cold-water coral Desmophyllum dianthus, a common and widespread solitary scleractinian species, whose reproduction strategy and larval dispersal are still poorly unknown.
  • 3. The genetic structure of D. dianthus was explored using 30 microsatellites in 347 specimens from 13 localities distributed in the Mediterranean Sea and Atlantic and Pacific Oceans.
  • 4. Results clearly reveal genetically differentiated populations in the Northern and Southern Hemispheres (FST = 0.16, FSC = 0.01, FCT = 0.15, P-values highly significant), and Chilean and New Zealand populations with independent genetic profiles.
  • 5. Marine connectivity patterns at different spatial scales are discussed to characterize larval dispersal and gene flow through the Northern and Southern Hemispheres.
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2.
LR Hunt  SM Smith  KR Downum  LD Mydlarz 《Marine drugs》2012,10(6):1225-1243
Gorgonian corals possess many novel natural products that could potentially mediate coral-bacterial interactions. Since many bacteria use quorum sensing (QS) signals to facilitate colonization of host organisms, regulation of prokaryotic cell-to-cell communication may represent an important bacterial control mechanism. In the present study, we examined extracts of twelve species of Caribbean gorgonian corals, for mechanisms that regulate microbial colonization, such as antibacterial activity and QS regulatory activity. Ethanol extracts of gorgonians collected from Puerto Rico and the Florida Keys showed a range of both antibacterial and QS activities using a specific Pseudomonas aeruginosa QS reporter, sensitive to long chain AHLs and a short chain N-acylhomoserine lactones (AHL) biosensor, Chromobacterium violaceium. Overall, the gorgonian corals had higher antimicrobial activity against non-marine strains when compared to marine strains. Pseudopterogorgia americana, Pseusopterogorgia acerosa, and Pseudoplexuara flexuosa had the highest QS inhibitory effect. Interestingly, Pseudoplexuara porosa extracts stimulated QS activity with a striking 17-fold increase in signal. The stimulation of QS by P. porosa or other elements of the holobiont may encourage colonization or recruitment of specific microbial species. Overall, these results suggest the presence of novel stimulatory QS, inhibitory QS and bactericidal compounds in gorgonian corals. A better understanding of these compounds may reveal insight into coral-microbial ecology and whether a therapeutic potential exists.  相似文献   
3.
Meroterpenes are widely distributed among marine organisms; they are particularly abundant within brown algae, but other important sources include microorganisms and invertebrates. In the present review the structures and bioactivities of meroterpenes from marine invertebrates, mainly sponges and tunicates, are summarized. More than 300 molecules, often complex and with unique skeletons originating from intra- and inter-molecular cyclizations, and/or rearrangements, are illustrated. The reported syntheses are mentioned. The issue of a potential microbial link to their biosynthesis is also shortly outlined.  相似文献   
4.
  1. It is essential to consider genetic composition for both conventional coral restoration management and for initiating new interventions to counter the significant global decline in living corals. Population genetic structure at a fine spatial scale should be carefully evaluated before implementing strategies to achieve self-sustaining ecosystems via coral restoration.
  2. This study investigated the population genetic structure of two acroporid species at Kume Island, Okinawa, Japan. There were 140 colonies of Acropora digitifera collected from seven study sites, and 81 colonies of Acropora tenuis from six sites. In total, 384 single nucleotide polymorphism (SNP) loci for A. digitifera and 470 SNPs for A. tenuis were obtained using a comparatively economical technique, Multiplexed ISSR Genotyping by sequencing.
  3. Observed heterozygosity was significantly lower than expected heterozygosity at all SNP sites in both acroporid species, suggesting deficient genetic diversity possibly caused by past massive coral bleaching. Even though both species are broadcast spawners, the population structure was different in the two species. No detectable structure was evident in A. digitifera, but two distinct clades were found in A. tenuis. The genetic homogeneity of A. digitifera at Kume Island suggests that this species could be used as a focal species for active restoration in terms of genetic differentiation at this island. By contrast, A. tenuis unexpectedly included two distinct clades with little or no admixture within a small study area, possibly representing two reproductively isolated cryptic species. Thus, when using A. tenuis, it would be prudent to avoid disturbing the genetic composition of wild populations until this question is answered.
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5.
Many bioactive products from benthic invertebrates mediating ecological interactions have proved to reduce predation, but their mechanisms of action, and their molecular identities, are usually unknown. It was suggested, yet scarcely investigated, that nutritional quality interferes with defensive metabolites. This means that antifeedants would be less effective when combined with energetically rich prey, and that higher amounts of defensive compounds would be needed for predator avoidance. We evaluated the effects of five types of repellents obtained from Antarctic invertebrates, in combination with diets of different energetic values. The compounds came from soft corals, ascidians and hexactinellid sponges; they included wax esters, alkaloids, a meroterpenoid, a steroid, and the recently described organic acid, glassponsine. Feeding repellency was tested through preference assays by preparing diets (alginate pearls) combining different energetic content and inorganic material. Experimental diets contained various concentrations of each repellent product, and were offered along with control compound-free pearls, to the Antarctic omnivore amphipod Cheirimedon femoratus. Meridianin alkaloids were the most active repellents, and wax esters were the least active when combined with foods of distinct energetic content. Our data show that levels of repellency vary for each compound, and that they perform differently when mixed with distinct assay foods. The natural products that interacted the most with energetic content were those occurring in nature at higher concentrations. The bioactivity of the remaining metabolites tested was found to depend on a threshold concentration, enough to elicit feeding repellence, independently from nutritional quality.  相似文献   
6.
The development of standardized and sustainable aquaculture techniques for the cultivation of marine organisms offers many advantages: it would help reduce the quantity of living material harvested from coral reefs; it could be used as an efficient means of rehabilitating impoverished reef ecosystems (e.g. by reseeding depleted natural stocks of corals); it would provide an educational and research tool for the intensive study of marine animal biology under controlled laboratory conditions.Here, we present the results of aquarium maintenance of 3 Red Sea soft coral species (Clavularia hamra, Nephthea sp., Litophyton arboreum) raised from field collected larvae. Planulae settlement was enhanced when dead coral fragments and stones freshly collected from the sea were added to the settlement dishes. Young colonies (n=106, 258, 60; respectively) were monitored for 307, 475 and 207 days, respectively. The survival rate at the end of the observations ranged between 17% and 30%. Growth rates of colonies differed and showed species-specific variations. The most successful growth was recorded in Nephthea where the average colony size reached 324.5 polyps. Current aquaculture techniques for alcyonarian corals not only reveal that these organisms can thrive in aquaria but also provide significantly improved yields of colonies, as compared with yields under field conditions. Our studies have shown that various steps involved in the cultivation of young corals in captivity may need to be specifically tailored to suit the coral species in question.  相似文献   
7.
甘健锋  俞晓磊  罗勇  黄林韬  刘骋跃  江雷  黄晖 《水产学报》2021,45(11):1854-1862
能量与营养物质的正常获取是维系造礁石珊瑚生命活动的基础,这主要与其两种营养方式—光合自养和异养营养有关。当前,国内外学者对造礁石珊瑚的研究以光合自养为主,而对其异养营养的认识则相对不足。基于此,本研究以鹿回头礁区(海南三亚)的3种代表性造礁石珊瑚—丛生盔形珊瑚、鹿角杯形珊瑚和美丽鹿角珊瑚为对象,通过投喂丰年虫无节幼体、水族用桡足类、酵母浸出粉溶液及水族珊瑚粮这4种食物,探讨了3种造礁石珊瑚的食性、摄食方式。结果显示,丛生盔形珊瑚对上述4种食物均表现出明显的摄食行为;相反,美丽鹿角珊瑚对4种食物均不表现摄食行为;鹿角杯形珊瑚只摄食尺寸较小的丰年虫无节幼体和水族珊瑚粮,并首次发现其在摄食丰年虫无节幼体时水螅体间相互协作以及通过释放肠系膜摄食水族珊瑚粮的现象。进一步研究丛生盔形珊瑚对丰年虫无节幼体的摄食速率和消化情况,发现其摄食速率与丰年虫无节幼体密度符合米氏方程,且其消化周期约为3 h。研究结果有助于更加深入地认识造礁石珊瑚摄食取向及其摄食过程,可为造礁石珊瑚人工养殖过程中的饵料选择提供借鉴。  相似文献   
8.
  1. Association between habitat structuring organisms and other species has great relevance for ecosystem‐based conservation measures.
  2. Those occurring in temperate areas, particularly in the upper portion of the continental margin, are mostly unknown or not properly understood because of the difficulty to discriminate co‐occurrence and real functional linkages among species.
  3. Deep water coral assemblages over the Carloforte Shoal (south‐west Sardinia; 180–210 m depth) were investigated using ROV surveys.
  4. During the surveys, more than 740 egg‐capsules of the spotted catshark Scyliorhinus canicula, identified after hatching experiments in captivity, were found attached exclusively to colonies of the long‐living black coral Leiopathes glaberrima.
  5. Although based on a spot finding, the results show that coral forests are not only hotspots of biodiversity, but can also serve as nursery grounds for S. canicula. The protection of these millennial coral forests is therefore to be considered a priority.
  相似文献   
9.
氮磷对珊瑚过氧化氢酶和超氧化物歧化酶活性的影响   总被引:1,自引:0,他引:1  
为研究不同浓度硝酸盐、铵盐和磷酸盐对斯氏角孔珊瑚、二异角孔珊瑚和澄黄滨珊瑚CAT和SOD活性的影响,设置硝酸盐、铵盐和磷酸盐高、中、低3种试验浓度对斯氏角孔珊瑚、二异角孔珊瑚和澄黄滨珊瑚分别进行8周的养殖观察。结果表明:斯氏角孔珊瑚以中等硝酸盐和铵盐浓度组CAT活性最高,高浓度磷酸盐组CAT活性高;以高浓度硝酸盐和磷酸盐组SOD活性最高,中等浓度铵盐组SOD活性最高。二异角孔珊瑚以中等浓度硝酸盐、铵盐和磷酸盐CAT活性最高;以中等浓度硝酸盐、铵盐组SOD活性最高,以高浓度磷酸盐组SOD活性最高。澄黄滨珊瑚以对照组CAT和SOD活性最高,说明澄黄滨珊瑚对营养盐的耐受性差。珊瑚CAT和SOD活性均出现峰值,与其他时间点比较差异显著(P0.05),是珊瑚在营养盐胁迫下从适应到中毒反应的临界值,说明珊瑚是可以间接评价海洋环境营养盐富集程度的指示生物。  相似文献   
10.
Three soft coral cuttings (finger soft coral, Sinularia sp.; black finger soft coral, Cladiella sp. and leather mushroom soft coral, Sarcophyton sp.) were selected to distinguish among the effects of five methods of attachment (adhering, containing, impaling, tethering and a natural attachment method used as a control) in a recirculating seawater system on healing time, time of self‐attachment, development of the cuttings and final survival. Three replicate and 30 cuttings per replicate (n = 30) were used for each treatment and the experimental period was 70 days. The results showed that the cuttings of Sinularia sp., Sarcophyton sp. and Cladiella sp. had already healed the wound area with pigmentation between 7 and 12 days for all the methods of attachment. The shortest time of self‐attachment for the Sinularia sp., Sarcophyton sp., and Cladiella sp. cuttings was obtained in the impaling method, with average values of 8.2 ± 0.9 days, 6.1 ± 0.1 days and 9.00 ± 0.8 days respectively. At the end of the experiment, the highest average final survival values of the Sinularia sp., Sarcophyton sp. and Cladiella sp. cuttings were obtained in the impaling method (86.7 ± 5.7%), the containing method (93.3 ± 5.7%) and the containing method (53.3 ± 5.7%), respectively. It was concluded from the study that the suitable methods of attachment for each soft coral were different and these methods are available for use in targeted propagation farms for restoration purposes.  相似文献   
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