RESUMEN
The utility of the mitochondrial genomes (mitogenomes) in analyzing the evolutionary history of animals has been proven. Five deep-sea corals (Bathypathes sp.1, Bathypathes sp.2, Schizopathidae 1, Trissopathes sp., and Leiopathes sp.) were collected in the South China Sea (SCS). Initially, the structures and collinearity of the five deep-sea coral mitogenomes were analyzed. The gene arrangements in the five deep-sea coral mitogenomes were similar to those in the order Antipatharia, which evidenced their conservation throughout evolutionary history. Additionally, to elucidate the slow evolutionary rates in Hexacorallia mitogenomes, we conducted comprehensive analyses, including examining phylogenetic relationships, performing average nucleotide identity (ANI) analysis, and assessing GC-skew dissimilarity combining five deep-sea coral mitogenomes and 522 reference Hexacorallia mitogenomes. Phylogenetic analysis using 13 conserved proteins revealed that species clustered together at the order level, and they exhibited interspersed distributions at the family level. The ANI results revealed that species had significant similarities (identity > 85%) within the same order, while species from different orders showed notable differences (identity < 80%). The investigation of the Hexacorallia mitogenomes also highlighted that the GC-skew dissimilarity was highly significant at the order level, but not as pronounced at the family level. These results might be attributed to the slow evolution rate of Hexacorallia mitogenomes and provide evidence of mitogenomic diversity. Furthermore, divergence time analysis revealed older divergence times assessed via mitogenomes compared with nuclear data, shedding light on significant evolutionary events shaping distinct orders within Hexacorallia corals. Those findings provide new insights into understanding the slow evolutionary rates of deep-sea corals in all lineages of Hexacorallia using their mitogenomes.
Asunto(s)
Antozoos , Evolución Molecular , Genoma Mitocondrial , Filogenia , Antozoos/genética , Antozoos/clasificación , Animales , Composición de BaseRESUMEN
Azooxanthellate scleractinian corals, a group of species that lack a symbiotic relationship with dinoflagellates, are influenced by environmental variables at various scales. As the global commitment to sustainably manage ocean ecosystems and resources rises, there is a growing need to describe biodiversity trends in previously unsampled areas. Benthic invertebrate research in South Africa is a developing field, and many taxa in deep water environments remain inadequately characterized. Recently, the South African azooxanthellate scleractinian fauna was taxonomically reviewed, but their distributional correlations with physical parameters have not been studied. Here we aim to understand the biodiversity gradients of the South African azooxanthellate coral fauna by analysing the environmental correlates of museum samples. The associated coordinate data were georeferenced and depth obtained from a national bathymetric dataset, prior to undertaking a multivariate analysis. This analysis encompassed several steps, including the grouping of the longitude and depth data (environmental data), identifying families characteristic of the group variability, and examining the correlation of the associated data with the biological data. Additionally, the analysis involved quantifying diversity patterns along the environmental gradients. Overall, our results confirmed two longitudinal groups (eastern margin [Group A] vs southern and western margin [Group B]) and 11 depth categories represented within two bathymetric zones (shallow [50-200 m] and deep [300-1000 m]). Caryophylliids, flabellids, and dendrophylliids contributed the most towards distinguishing longitudinal and depth gradients. Both abiotic variable (longitudinal and depth) partially explained coral distribution patterns, with depth being highly correlated to the species variation observed. Data limitations within our data set resulted to unexplained variance, however, despite these limitations, the study demonstrates that historical museum samples provide a valuable data source that can fill research sampling gaps and help improve the understanding of biodiversity patterns of the coral fauna in under sampled marine ecosystems.
Asunto(s)
Antozoos , Biodiversidad , Animales , Antozoos/clasificación , Sudáfrica , Ecosistema , Arrecifes de CoralRESUMEN
The mucus surface layer serves vital functions for scleractinian corals and consists mainly of carbohydrates. Its carbohydrate composition has been suggested to be influenced by environmental conditions (e.g., temperature, nutrients) and microbial pressures (e.g., microbial degradation, microbial coral symbionts), yet to what extend the coral mucus composition is determined by phylogeny remains to be tested. To investigate the variation of mucus carbohydrate compositions among coral species, we analyzed the composition of mucosal carbohydrate building blocks (i.e., monosaccharides) for five species of scleractinian corals, supplemented with previously reported data, to discern overall patterns using cluster analysis. Monosaccharide composition from a total of 23 species (belonging to 14 genera and 11 families) revealed significant differences between two phylogenetic clades that diverged early in the evolutionary history of scleractinian corals (i.e., complex and robust; p = 0.001, R2 = 0.20), mainly driven by the absence of arabinose in the robust clade. Despite considerable differences in environmental conditions and sample analysis protocols applied, coral phylogeny significantly correlated with monosaccharide composition (Mantel test: p < 0.001, R2 = 0.70). These results suggest that coral mucus carbohydrates display phylogenetic dependence and support their essential role in the functioning of corals.
Asunto(s)
Antozoos , Moco , Filogenia , Antozoos/genética , Antozoos/metabolismo , Antozoos/clasificación , Animales , Moco/química , Moco/metabolismo , Carbohidratos/análisis , Carbohidratos/química , Monosacáridos/análisisRESUMEN
The integration of morphological and molecular lines of evidence has enabled the family Deltocyathidae to be erected to accommodate Deltocyathus species that were previously ascribed to the family Caryophylliidae. However, although displaying the same morphological characteristics as other species of Deltocyathus , molecular data suggested that D. magnificus was phylogenetically distant from Deltocyathidae, falling within the family Turbinoliidae instead. To elucidate the enigmatic evolutionary history of this species and skeletal microstructural features, the phylogenetic relationships of Deltocyathidae and Turbinoliidae were investigated using nuclear ultraconserved and exon loci and complete mitochondrial genomes. Both nuclear and mitochondrial phylogenomic reconstructions confirmed the position of D. magnificus within turbinolids. Furthermore, a novel mitochondrial gene order was uncovered for Deltocyathidae species. This gene order was not present in Turbinoliidae or in D. magnificus that both have the scleractinian canonical gene order, further indicating the taxonomic utility of mitochondrial gene order. D. magnificus is therefore formally moved to the family Turbinoliidae and accommodated in a new genus (Dennantotrochus Kitahara, Vaga & Stolarski, gen. nov.). Surprisingly, turbinolids and deltocyathids do not differ in microstructural organisation of the skeleton that consists of densely packed, individualised rapid accretion deposits and thickening deposits composed of fibres perpendicular to the skeleton surface. Therefore, although both families are clearly evolutionarily divergent, macromorphological features indicate a case of skeletal convergence while these may still share conservative biomineralisation mechanisms. ZooBank: urn:lsid:zoobank.org:pub:5F1C0E25-3CC6-4D1F-B1F0-CD9D0014678E.
Asunto(s)
Antozoos , Filogenia , Animales , Antozoos/genética , Antozoos/clasificación , Genoma Mitocondrial/genética , Evolución BiológicaRESUMEN
Black corals occur as part of benthic assemblages from shallow to deep waters in all oceans. Despite the importance in many benthic ecosystems, where these act as biodiversity aggregators, antipatharians remain poorly studied, with 75% of the known species occurring below recreational SCUBA diving depth limits. Currently, information regarding the diversity and evolutionary history is limited, with most studies focusing on Hawaii and the South Pacific Ocean. Other regions of the world have received less attention, such as the Red Sea, where only two black coral families and four genera have been recorded. We provide the first analysis of the molecular diversity of black corals in the eastern Gulf of Aqaba and the northern and central Saudi Arabian Red Sea, based on a dataset of 161 antipatharian colonies collected down to 627 m deep. Based on specimen morphology, we ascribed our material to 11 genera belonging to 4 of the 7 known Antipatharia families, i.e. Antipathidae, Aphanipathidae, Myriopathidae and Schizopathidae. The genus level phylogeny of three intergenic mitochondrial regions, the trnW-IGR-nad2 (IgrW ), nad5-IGR-nad1 (IgrN ) and cox3-IGR-cox1 was reconstructed including previously published material. Overall, we recovered six molecular clades that included exclusively Red Sea sequences, with the highest diversity occurring at mesophotic depths. This study highlights that diversity of black corals in the Red Sea is much higher than previously known, with seven new generic records, suggesting that this basin may be a hotspot for antipatharian diversity as is known for other taxa. Our results recovered unresolved relationships within the order at the familial and generic levels. This emphasises the urgent need for an integration of genomic-wide data with a re-examination of informative morphological features necessary to revise the systematics of the order at all taxonomic levels.
Asunto(s)
Antozoos , Filogenia , Antozoos/genética , Antozoos/clasificación , Animales , Océano Índico , Arabia Saudita , Especificidad de la Especie , Biodiversidad , Variación Genética/genéticaRESUMEN
Despite the widespread use of integrative taxonomic approaches, many scleractinian coral genera and species remain grouped in polyphyletic families, classified as incertae sedis or simply understudied. Oculinidae Gray, 1847 represents a family for which many taxonomic questions remain unresolved, particularly those related to some of the current genera, such as Oculina Lamark, 1816 or recently removed genera, including Cladocora Ehrenberg, 1834 and Madrepora Linnaeus, 1758. Cladocora is currently assigned to the family Cladocoridae Milne Edwards & Haime, 1857 and a new family, Bathyporidae Kitahara, Capel, Zilberberg & Cairns, 2024, was recently raised to accommodate Madrepora . However, the name Bathyporidae is not valid because this was not formed on the basis of a type genus name. To resolve taxonomic questions related to these three genera, the evolutionary relationships are explored through phylogenetic analyses of 18 molecular markers. The results of these analyses support a close relationship between the species Oculina patagonica and Cladocora caespitosa , indicating that these may belong to the same family (and possibly genus), and highlighting the need for detailed revisions of Oculina and Cladocora . By contrast, a distant relationship is found between these two species and Madrepora oculata , with the overall evidence supporting the placement of Madrepora in the resurrected family Madreporidae Ehrenberg, 1834. This study advances our knowledge of coral systematics and highlights the need for a comprehensive review of the genera Oculina , Cladocora and Madrepora .
Asunto(s)
Antozoos , Filogenia , Animales , Antozoos/clasificación , Especificidad de la EspecieRESUMEN
The Arabian Peninsula accounts for approximately 6% of the world's coral reefs. Some thrive in extreme environments of temperature and salinity. Using 51 Autonomous Reef Monitoring Structure (ARMS), a standardized non-destructive monitoring device, we investigated the spatial patterns of coral reef cryptobenthic diversity in four ecoregions around the Arabian Peninsula and analyzed how geographical and/or environmental drivers shape those patterns. The mitochondrial cytochrome c oxidase subunit I (COI) gene was used to identify Amplicon Sequence Variants and assign taxonomy of the cryptobenthic organisms collected from the sessile and mobile fractions of each ARMS. Cryptobenthic communities sampled from the two ecoregions in the Red Sea showed to be more diverse than those inhabiting the Arabian (Persian) Gulf and the Gulf of Oman. Geographic distance revealed a stronger relationship with beta diversity in the Mantel partial correlation than environmental distance. However, the two mobile fractions (106-500 µm and 500-2000 µm) also had a significant correlation between environmental distance and beta diversity. In our study, dispersal limitations explained the beta diversity patterns in the selected reefs, supporting the neutral theory of ecology. Still, increasing differences in environmental variables (environmental filtering) also had an effect on the distribution patterns of assemblages inhabiting reefs within short geographic distances. The influence of geographical distance in the cryptofauna assemblages makes these relevant, yet usually ignored, communities in reef functioning vulnerable to large scale coastal development and should be considered in ecosystem management of such projects.
Asunto(s)
Biodiversidad , Arrecifes de Coral , Complejo IV de Transporte de Electrones , Animales , Complejo IV de Transporte de Electrones/genética , Antozoos/genética , Antozoos/clasificación , Océano ÍndicoRESUMEN
During this work, over 200 specimens of sea pens (Anthozoa: Octocorallia: Pennatuloidea), collected in the Mar del Plata submarine canyon and outskirts (38S, up to 3500 m depth) during 2012 and 2013 were analyzed. Of the total, about 160 were identified in seven species of Anthoptilum, Distichoptilum, Kophobelemnon, Pseudumbellula, Solumbellula and Umbellula. Three of those represent new records for the southwestern Atlantic Ocean off Argentina.
Asunto(s)
Antozoos , Animales , Antozoos/clasificaciónRESUMEN
Scleractinian corals (stony corals) are the most abundant reef-forming cnidarians found in coral reefs throughout the world. Despite their abundance and ecological importance, information about the diversity of their toxins and their biological activities is very scarce. In this study, the chemical composition and the biological activities of the aqueous extracts of Pseudodiploria strigosa, Porites astreoides and Siderastrea siderea, three scleractinian corals from the Mexican Caribbean, have been assessed for the first time. Methods: Toxicity of the extracts was assessed in crickets; the presence of cytolysins was detected by the hemolysis assay; the vasoconstrictor activity was determined by the isolated rat aortic ring assay; the nociceptive activity was evaluated by the formalin test. The presence of phospholipases A2 (PLA2), serine proteases, and hyaluronidases was determined by enzymatic methods. Low-molecular-weight fractions were obtained by gel filtration chromatography and ultrafiltration. Results: Extracts from the three species were toxic to crickets, induced hemolysis in human and rat erythrocytes, produced vasoconstriction on isolated rat aortic rings, and presented phospholipase A2 and serine-protease activity. Despite the fact that these corals are not considered to be harmless to humans, the extracts generated significant nociceptive responses. The matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of the low-molecular-weight fractions revealed the presence of peptides within a mass range of 3000 to 6000 Da. These fractions were toxic to crickets and two of them induced a transitory vasoconstrictor effect on isolated rat aortic rings. Conclusion: This study suggests that scleractinian corals produce low-molecular-weight peptides that are lethal to crickets and induce vasoconstriction.
Asunto(s)
Antozoos/clasificación , Antozoos/microbiología , Antozoos/química , BiotaRESUMEN
Carijoa riisei (Octocorallia: Cnidaria), a western Atlantic species, has been reported in the Pacific as an invasive species for nearly forty years. C. riisei has been recently observed overgrowing native octocorals at several rocky-coral littorals in the Colombian Tropical Eastern Pacific-(TEP). C. riisei has inhabited these reefs for at least 15 years but the aggressive overgrowth on other octocorals have been noted until recently. Here, we surveyed for the first time the distribution and inter-specific aggression by C. riisei in both coastal and oceanic areas colonized in the Colombian TEP (Malpelo, Gorgona and Cabo Corrientes), including preliminary multiyear surveys during 2007-2013. We observed community-wide octocoral mortalities (including local extinction of some Muricea spp.) and a steady occurrence of competing and overgrowing Pacifigorgia seafans and Leptogorgia seawhips. In Gorgona Island, at two different sites, over 87% (n=77 tagged colonies) of octocorals (Pacifigorgia spp. and Leptogorgia alba) died as a result of C. riisei interaction and/or overgrowth between 2011 and 2013. C. riisei overgrows octocorals with an estimate at linear growth rate of about 1cm m-1. The aggressive overgrowth of this species in TEP deserves more attention and regular monitoring programs. Rev. Biol. Trop. 62 (Suppl. 1): 199-207. Epub 2014 February 01.
Carijoa riisei (Octocorallia: Cnidaria), una especie nativa del Atlántico Occidental. Sin embargo, se ha reportado como especie exótica invasora en el Pacífico desde hace unos cuarenta años y en la costa occidental de Colombia hace 15-20 años. Recientemente C. riisei se ha observado sobrecreciendo octocorales nativos en varios litorales rocosos coralinos en el Pacífico Oriental Tropical-(POT) de Colombia. C. riisei ha habitado estos arrecifes durante al menos 15 años, pero este comportamiento agresivo frente a otros octocorales no se habían notado hasta hace unos pocos años. En este estudio, se evalúa por primera vez, en las zonas costeras y oceánicas, la distribución e incidencia C. riisei en otros octocorales del POT colombiano (Malpelo, Gorgona y Cabo Corrientes), incluyendo información observaciones entre 2007-2013. Hemos observado mortalidad en toda la comunidad de octocorales (incluyendo la extinción local de algunas especies de Muricea) y una constante competencia y cubrimiento de abanicos de mar Pacifigorgia y gorgonáceos Leptogorgia. C. riisei presento una tasa lineal de crecimiento sobre otros octocorales de aproximadamente 1 cm m-1. El comportamiento agresivo de C. riisei en el POT merece más atención y programas regulares de monitoreo.
Asunto(s)
Cnidarios/crecimiento & desarrollo , Antozoos/clasificación , Especies Introducidas , Colombia , Arrecifes de CoralRESUMEN
BACKGROUND: Marine invertebrate-associated microbial communities are interesting examples of complex symbiotic systems and are a potential source of biotechnological products. RESULTS: In this work, pyrosequencing-based assessment from bacterial community structures of sediments, two sponges, and one zoanthid collected in the Mexican Caribbean was performed. The results suggest that the bacterial diversity at the species level is higher in the sediments than in the animal samples. Analysis of bacterial communities' structure showed that about two thirds of the bacterial diversity in all the samples belongs to the phyla Acidobacteria and Proteobacteria. The genus Acidobacteriumappears to dominate the bacterial community in all the samples, reaching almost 80% in the sponge Hyrtios. CONCLUSIONS: Our evidence suggests that the sympatric location of these benthonic species may lead to common bacterial structure features among their bacterial communities. The results may serve as a first insight to formulate hypotheses that lead to more extensive studies of sessile marine organisms' microbiomes from the Mexican Caribbean.
Asunto(s)
Animales , Poríferos/microbiología , Antozoos/microbiología , Acidobacteria/fisiología , Simpatría , Microbiota/fisiología , Filogenia , Poríferos/clasificación , Simbiosis/fisiología , ARN Ribosómico 16S/análisis , Región del Caribe , Sedimentos Geológicos/microbiología , Proteobacteria/clasificación , Proteobacteria/fisiología , Antozoos/clasificación , Biodiversidad , MéxicoRESUMEN
Gorgonians are important components of coastal ecosystems, as they provide niches, natural compounds with medical applications and are used as bioindicators. Species composition and assemblage structure of gorgonians (Anthozoa: Octocorallia) were studied along a bathymetric profile in the Southern Mexican Pacific coast. Species composition was based on specimens collected within a depth range of 0-70m in 15 sites. The relative abundance of species was determined in six sites at four depths (5, 10, 20 and 25m) using three 10m2 transects at each depth level. Twenty-seven species of gorgonians belonging to six genera and three families were registered. The species composition varied with depth: 11 species were distributed between 0-25m depth, while 17 species were found between 40-70m depth interval. The shallow zone is characterized by a relatively large abundance of gorgonians, dominated by colonies of Leptogorgia cuspidata and L. ena. In contrast, the deepest zone was characterized by relatively low abundance of gorgonians, dominated by L. alba, the only species observed in both depth intervals. The similarity analysis showed differences in the composition and abundance of species by depth and site, suggesting that the main factor in determining the assemblage structure is depth. Results of this study suggest that the highest richness of gorgonian species in the study area may be located at depths of 40-70m, whereas the highest abundances are found between 5 and 10m depth. This study represents a contribution to the poorly known eastern Pacific gorgonian biota.
La composición de especies y estructura de la comunidad de gorgonáceos se determinó a lo largo de un perfil batimétrico en la costa suroeste del Pacífico Mexicano. La composición de especies se realizó a través de una revisión y recolecta de especímenes entre 0 y 70m de profundidad en 15 sitios de muestreo. La caracterización de la estructura de la comunidad se realizó en seis sitios, en los cuales se colocaron tres transectos de 10m² cada uno a 5, 10, 20 y 25m de profundidad. Se encontraron 27 especies de gorgonáceos pertenecientes a seis géneros y tres familias; aunque seis especies requieren ser confirmadas. La mayor riqueza de especies se registró entre 40 y 70m. La estructura de la comunidad entre 5 y 25m de profundidad mostró la existencia de dos zonas con la misma composición de especies pero con diferente abundancia relativa: una somera entre 5 y 10m de profundidad, caracterizada por una mayor abundancia de gorgonáceos y dominado por colonias de Leptogorgia cuspidata y Leptogorgia ena y una zona profunda entre 20 y 25m de profundidad, caracterizada por una baja abundancia de gorgonáceos y dominada por colonias de Leptogorgia alba.
Asunto(s)
Animales , Antozoos/clasificación , Ecosistema , Biodiversidad , México , Densidad de PoblaciónRESUMEN
Coral reefs in the Mexican Pacific and notably those of the continental coastline of Colima state are still poorly studied. Fortunately, recent efforts have been carried out by researchers from different Mexican institutions to fill up these information gaps. The aim of this study was to determine the ecological structure of the rich and undisturbed coral building communities of Carrizales by using the point transect interception method (25m-long). For this, three survey expeditions were conducted between June and October 2005 and September 2006; and for comparison purposes, the reef was subdivided according to its position in the bay, and depth (0 to 5m, and 6 to 10m). Thirteen coral species were observed in the area, with Pocillopora verrucosa as the most abundant, contributing up to 32.8% of total cover, followed by Porites panamensis and Pocillopora capitata with 11% and 7%, respectively. Other species, Pocillopora damicornis, Pavona gigantea, Pocillopora eydouxi and Pocillopora inflata accounted for 1.5% to 2% of coral cover whereas the remaining five species had cover of less than 1%. Seven of the observed species represented new records for Colima state coast- line: Pocillopora eydouxi, P. inflata, P. meandrina, Pavona duerdeni, P. varians, Psammocora stellata and P. contigua. This last species is a relevant record, because it has never been observed before in the Eastern Pacific. Although there was no significant difference (ANOVA, p=0.478) neither in the abundance between the sides of the bay, nor between the depths considered, and the shallow zone observed the higher coral cover. Live coral cover was up to 61%, one of the highest ever reported for the Mexican Pacific, including the Gulf of California. The observed values of diversity (H´=0.44±0.02), uniformity (J´=0.76±0.02), and taxonomic distinctness index (Δ*=45.87±3.16), showed that currently this is the most important coral reef of Colima coastline. Currently, this region does not show any disturbance effects, but the increasing economic development of Manzanillo, as one of the main commercial ports of Mexico, its proximity to the reef, and the burgeoning number of tourists, may have some ecosystem impacts, for which management and conservation plans for Colima coastline are highly recommended.
El conocimiento ecológico de corales arrecifales en el Pacífico mexicano es escaso, por lo que el objetivo de este trabajo fue determinar la estructura de la comunidad de corales hermatípicos en el arrecife de Carrizales, Colima, mediante el uso de transectos y buceo autónomo (junio y octubre 2005, septiembre 2006). De las 13 especies de corales encontradas, Pocillopora verrucosa fue la más abundante y siete representan nuevos registros, sobresaliendo Psammocora contigua, primer registro para el Pacífico Oriental. No hubo diferencias significativas de abundancia entre profundidades, pero la zona somera presenta una mayor cobertura. Este sitio presenta una de las riquezas y cobertura de coral más alta (61%) en el Pacífico Mexicano y valores de diversidad (H´=0.44±0.02), uniformidad (J´=0.76±0.02), y de diferenciación taxonómica (Δ*=45.87±3.16) relativamente altos. Actualmente la región no presenta grandes perturbaciones pero el creciente desarrollo económico de Manzanillo, uno de los principales puertos comerciales del país, además del creciente número de turistas, podrían afectar al arrecife, por lo que se sugiere implementar medidas de protección con el fin de mantener al arrecife más importante del litoral de Colima.
Asunto(s)
Animales , Antozoos/clasificación , Biodiversidad , Arrecifes de Coral , Monitoreo del Ambiente/métodos , México , Densidad de Población , Dinámica PoblacionalRESUMEN
The isolated Isla del Coco experiences periodic, extreme disturbances which devastate coral reefs surrounding the island. Scleractinian corals build the physical structure of the reef therefore ecosystem recovery relies on coral species recovery. Coral recruits can be of sexual or asexual origin, and the relative success of the two recruit types influences the speed and spread of recovery processes. Here we focus on the massive coral, Porites lobata, because it is the main reef-builder around Isla del Coco to describe the relative contribution of asexual and sexual recruits to population maintenance. P. lobata samples were collected using a spatially explicit random sampling design in three plots at Isla del Coco: Punta Ulloa (n=17), Bahía Weston (n=20) and Punta María (n=20) and samples were genotyped with 11 microsatellite markers. Additional sampling was conducted at three “coastal” sites near the Costa Rican mainland (Isla del Caño Biological Reserve): Caño1 (n=8), Caño2 (n=10), Caño5 (n=11) to compare the contributions of asexual and sexual recruits at Isla del Coco sites to coastal sites. Isla del Coco sites were characterized by small colony size (>60% of colonies <0.5m2) and high sexual reproduction. Sites were either mostly or entirely sexual,consisting of only unique genotypes (N G/N= 0.90-1.00; G O/G E=0.83-1.00; D=0.99-1.00). Although there were no significant differences in genetic diversity (number of alleles per locus, number of private alleles) or colony size between Isla del Coco and the coastal sites, the coastal sites exhibited a greater range of genotypic diversity from moderately asexual (N G/N=0.5; G O/G E=0.36; D=0.8) to purely sexual (N G/N=1.0; G O/G E=1.0; D=1.0). The mode of asexual reproduction in P. lobata is likely fragmentation of adult colonies rather than asexual larval production because ramets of P. lobata occurred close together and asexually produced larvae have not been reported in gonochoric broadcast spawners like P. lobata. Frequent sexual reproduction at Isla del Coco National Park might represent a resource for rapid recovery following extreme El Niño-Southern Oscillation (ENSO) disturbance events. In contrast, larger, asexually-produced fragments rather than smaller, sexually-produced larvae appear to have the advantage at some coastal sites. The high frequency of sexual reproduction at Isla del Coco indicates that not only are sexual partners available but also current conditions are favorable for the delivery of larvae and the rate of predation on small larval recruits must be moderate.
Los ambientes marinos del Parque Nacional Isla del Coco experimentan perturbaciones extremas periódicamente como por ejemplo El Niño-Oscilación del Sur (ENOS) que han devastado las comunidades coralinas. La cobertura coralino se redujo drásticamente durante El Niño de 1982-83. Los corales escleractinios construyen la estructura física de los arrecifes así que la recuperación de estos ecosistemas depende de que los corales se recuperen. Los corales pueden reproducirse sexual y asexualmente, y el éxito relativo de cada forma de reproducción va a guiar el proceso de recuperación con implicaciones potenciales a la diversidad de las comunidades asociadas. En la mayoría de los arrecifes alrededor de la Isla del Coco, el coral masivo, Porites lobata, es la especie constructora predominante. Si la diversidad genotípica (clonal) de esta especie es alta, la diversidad de individuos va a ser más alta resultando en mayor resilencia frente a condiciones ambientales extremas. Alternativamente, una diversidad genotípica baja es indicativo de una estrategia reproductiva asexual posiblemente resultando en el mantenimiento de genotipos bien adaptados aunque la población decline. Aquí, usamos 11 marcadores microsatélite para investigar la contribución relativa de la reproducción sexual o asexual en la recuperación de los arrecifes en el Parque Nacional Isla del Coco. En la Isla del Coco se recolectaron muestras en: Punta Ulloa (n=17), Bahía Weston (n=20) y Punta María (n=20), y para comparar, se recolectaron muestras en localidades cerca de o en la costa continental de Costa Rica; Reserva Biológica Isla del Caño: Caño1 (n=8), Caño2 (n=10) y Caño5 (n=11), y Tres Hermanas, Parque Nacional Marino Ballena (n=4), utilizando un diseño de muestreo espacialmente explícito. Las colonias de la Isla del Coco son generalmente pequeñas (>60% de las colonias <0.5m2) y se observó poca reproducción asexual. En la mayoría de los sitios la reproducción era mayormente sexual (NG/N= 0.90-0.94; GO/GE =0.63-0.74; D=0.99) o totalmente sexual (N G/N= 1.0; G O/G E =1.0; D=1.0), por lo que consiste decolonias con genotipos únicos. En contraste, los sitios costeros tenían un ámbito de predominantemente asexual y genotípicamente pobre (N G/N =0.5; G O/G E =0.11; D=0.5) a totalmente sexual (N G/N= 1.0; G O/G E =1.0; D=1.0). No hubo diferencia en diversidad genética (número de alelos por locus, número de alelos privados) o distribución de tamaño por región. La alta diversidad genotípica del Parque Nacional Isla del Coco indica reproducción sexual frecuente y el potencial para la recuperación rápida de los arrecifes después de perturbaciones severas. En los sitios costeros, la fragmentación asexual de colonias grandes (>2.5m2) y por lo tanto, potencialmente colonias bien adaptadas, puede aumentar las resistencia y resilencia de los sistemas.
Asunto(s)
Islas del Pacífico , Antozoos/clasificación , Arrecifes de Coral , Costas (Litoral)/análisis , Costa Rica , El Niño Oscilación del Sur/efectos adversos , El Niño Oscilación del SurRESUMEN
Little evidence exists on the dependence between the presence and abundance of juvenile hermatypic corals and the conditions of their habitats, despite that juveniles contribute with the understanding of the community structure and its reproductive success. To assess this, the abundance of nine species of juvenile corals was correlated with eight macro-habitat (location of the reef on shelf, depth) and micro-habitat (type and inclination of the substrate, exposure to light, texture and amount of sediment accumulated on bottom, potential growth area for juveniles) conditions. Sampling was conducted in four insular coral reefs in the Colombian Caribbean: two oceanic and two continental reefs (influenced by large rivers), covering a total of 600m2 and the distribution of corals on a vertical gradient. Contingency tables and coefficients (magnitude) and multiple correspondence analyses were used to evaluate the dependency ratios for each species. The results showed that Agaricia tenuifolia displayed the most robust pattern of dependence (two high and two moderate), significant for juveniles present at a high frequency in continental reefs, devoid of potential area for juvenile growth (surrounded by macroalgae), and covering horizontal substrates exposed to light. The juveniles were associated with a habitat of moderate to high bottom accumulation of extremely fine sediment. Porites astreoides presented four moderate dependencies; ocean reefs between 2-16m depths, a high frequency of juveniles on horizontal substrates, exposed to light, non-sedimented and occupied by competitors. Siderastrea siderea displayed three moderate dependences for juveniles in cryptic zones, inclined substrate and devoid of competitors. A. lamarcki, Leptoseris cucullata and A. agaricites presented two moderate dependences; these species share high abundance of juveniles in habitats with no sediment, exposed to light and occupied by competitors (except A. agaricites). The P. porites, Favia fragum and Montastraea cavernosa species had a moderate dependence with high incidence of juveniles in ocean reefs and microhabitats exposed to light. For the nine species, results indicate that the presence (colonization), abundance and survival of juveniles, depend on certain species-specific particularities of the habitat. However, the juveniles show high tolerance and plasticity to a range of habitat variables, given their independence and low dependence observed in over 50% of the variables assessed.
Existe poca evidencia sobre la dependencia entre la abundancia de juveniles de corales hermatípicos y las condiciones del hábitat. La abundancia de corales juveniles se relacionó con condiciones del hábitat a macro (ubicación del arrecife, profundidad) y microescala (tipo e inclinación del sustrato, exposición a luz, textura y cantidad de sedimento, área de crecimiento potenial de juveniles). El muestreo se realizó en cuatro arrecifes insulares del Caribe colombiano. La dependencia se evaluó usando tablas y coeficientes de contingencia y análisis de correspondencias múltiples. Agaricia tenuifolia mostró las dependencias más robustas, siendo significativas para juveniles presentes frecuentemente en arrecifes continentales, sustrato horizontal expuesto a luz, con competidores. Los juveniles se asociaron con moderado a alto sedimento muy fino acumulado en el fondo. Porites astreoides presentó cuatro dependencias; alta frecuencia en sustrato expuesto a luz, horizontal, sin sedimento, con competidores y en arrecifes oceánicos entre 2-16m. Siderastrea siderea exhibió tres dependencias, para juveniles en lugares crípticos, sustrato inclinado y sin competidores. A. lamarcki, Leptoseris cucullata, A. agaricites, P. porites, Favia fragum y Montastraea cavernosa mostraron el menor número de dependencias, compartiendo alta frecuencia en hábitats sin sedimento, expuestos a luz, con competidores y en arrecifes oceánicos. Los resultados sugieren que la abundancia y sobrevivencia de juveniles dependen de ciertas particularidades especie-específicas del hábitat; sin embargo, los juveniles presentan tolerancia a una amplia gama de variables del hábitat.
Asunto(s)
Animales , Antozoos/clasificación , Arrecifes de Coral , Fenómenos Ecológicos y Ambientales , Región del Caribe , Colombia , Densidad de PoblaciónRESUMEN
Structure and injuries of octocoral communities (Octocorallia: Alcyonacea) of Ecological Reserve Siboney-Juticí, Santiago de Cuba, Cuba. In the spur-and-groove reefs of the Ecological Reserve Siboney-Juticí (Southeast Cuba) octocorals are one of the predominant components of the sessile fauna. Main objectives of the present paper are characterizing the composition, structure and conservation status of the octocoral communities and assessing on the prevailing environmental conditions in the study area. For data collection, six sampling sites were located every 2-3km ranging from 12m to 17m depth along the spur-and-groove reefs. In each site, 22-26 1m² quadrants were zigzag arranged every 2m. The density of colonies was determined per site. The severity degree and predictability of environmental conditions were inferred by using the Heterogeneity and Equitability indexes, respectively. Hydrodynamic stress and the Comparative Pollution Index were also assessed. Current affectations of the octocoral communities were also determined and classified into four main categories: mechanical damage, diseases, predation and invertebrate and macroalgae overgrowth. As a result, 25 species represented by 752 colonies were recorded and Eunicea flexuosa and Gorgonia ventalina were the most abundant. The occurrence of Eunicea succinea forma succinea constituted the first report for Eastern Cuba. Site densities ranged from 3.58±1.84 to 7.58±2.16 colonies/m² and considered from moderate to low. The biggest densities were reported at both sides of the San Juan River mouth. Despite of the composition and structure of the octocoral communities, low to high hydrodynamic stress and low and moderate levels of contamination were inferred, it is likely that these indexes could have been overestimated due to the sensitivity of the indicator species to other factors such as sedimentation. The environmental conditions were mostly favorable and stable. In general, the number of dead colonies was low and mostly caused by the detachment of the substrate and overgrowth of Millepora alcicornis. Injuries were mainly brought about by mechanical damage, followed by coenenchyme loss, predation by Cyphoma gibbosum and macroalgae overgrowth. On the other hand, negative effects by Hermodice carunculata predation, bleaching, Red Band and Black Band Disease were not observed. Among sampled species, G. ventalina colonies were the most severely damaged within the community. As a whole, octocoral communities of spur-and-groove reefs in the Ecological Reserve Siboney-Juticí showed a good conservation status. Rev. Biol. Trop. 58 (4): 1211-1221. Epub 2010 December 01.
Se estudió la comunidad de octocorales del arrecife de macizos y canales de la Reserva Ecológica Siboney- Juticí (sur oriente de Cuba) con el objetivo de caracterizar su composición, estructura y estado de conservación, así como inferir a partir de estas las condiciones ambientales imperantes en el área. La investigación se realizó entre enero y junio de 2009, en seis localidades ubicadas entre 12m y 17m de profundidad. Como unidad de muestreo se empleó un marco de 1m², el cual fue puesto en zigzag cada 2m sobre la superficie del arrecife de macizos. Se determinó, por localidad, la densidad de colonias y se infirieron los grados de severidad, constancia ambiental, tensión hidrodinámica y el Índice Comparativo de Contaminación. Se determinaron, además, los daños en la comunidad de octocorales. Se analizaron 752 colonias e identificaron 25 especies de octocorales. Eunicea flexuosa y Gorgonia ventalina fueron las especies más abundantes. La densidad fluctuó entre 3.58±1.84 colonias/m² y 7.58±2.16 colonias/ m² (densidad de baja a moderada tendiendo a baja). En la zona se infirió una tensión hidrodinámica entre baja y alta, con niveles de contaminación bajos y moderados, y un ambiente generalmente favorable y constante. Los daños de tipo mecánico fueron los más frecuentes, siendo G. ventalina la especie con más colonias dañadas. La comunidad de octocorales del hábitat de macizos y canales de la Reserva Ecológica Siboney-Juticí presentó un buen estado de conservación.
Asunto(s)
Animales , Antozoos/clasificación , Conservación de los Recursos Naturales , Monitoreo del Ambiente , Contaminación del Agua/análisis , Antozoos/fisiología , Biodiversidad , Cuba , Densidad de Población , Dinámica Poblacional , Agua de MarRESUMEN
This paper summarizes the results of a monitoring event designed to track the recovery of a repaired coral reef injured by the M/V Alec Owen Maitland vessel grounding incident of October 25, 1989. This grounding occurred within the Florida Keys National Marine Sanctuary. Pursuant to the National Marine Sanctuaries Act, NOAA recovers money for injury to Sanctuary resources, and uses it to restore those resources. A monitoring program tracks patterns of recovery, in order to determine the success of restoration measures. To evaluate success, reference habitats adjacent to the restoration site are concurrently monitored to compare the condition of restored areas with natural areas. Restoration of this site was completed in September 1995 by means of cement and limestone rock, and the monitoring results from summer 2007 are presented. Monitoring consisted of omparison of the biological conditions in the restored area with the reference area. Monitored corals are divided into the Orders: Gorgonians, Milleporans, and Scleractinians. Densities at the restored and reference areas are compared, and are shown to be greater in the restored. Size-class frequency distributions for the most abundant Scleractinians are examined, and reveal that the restoration is converging on the reference area. Also, for the Scleractinians, number and percentage of colonies by species, as well as several common biodiversity indices are provided; measures for the restored area approximate the reference area. A quantitative comparison of colony substrate settlement preference in the restored area is provided for all Orders, and for Scleractinians is further broken down for the two most frequent Genera. Rev. Biol. Trop. 58 (Suppl. 3): 151-161. Epub 2010 October 01.
Este artículo sintetiza los resultados del seguimiento diseñado para medir la recuperación de un arrecife restaurado que fue impactado por el encallamiento del M/V Alec Owen Maitland el 25 de octubre de 1989. Este encallamiento ocurrió en el área que comprende el Santuario Marino Nacional de los Cayos de Florida. De acuerdo con la Ley de los Santuarios Marinos Nacionales, la NOAA cobra dinero por daños a los recursos del Santuario y los usa para restaurar dichos recursos. Un programa de seguimiento o monitoreo mide los patrones de recuperación para determinar el éxito de las medidas de restauración. Para evaluar el éxito, hábitats de referencia adyacentes al sitio de restauración son examinados para comparar las condiciones de las áreas restauradas con las naturales. La restauración de este lugar se completó en septiembre de 1995 utilizando roca de cemento y caliza y los resultados del seguimiento desde el verano del 2007 son presentados. Se compararon las condiciones biológicas entre el área restaurada y la de referencia. Los corales evaluados se dividieron en tres Órdenes: Gorgonios, Milleporinos y Escleractinios. Se compararon las densidades en las áreas de restauración y de referencia, siendo la densidad más grande en las áreas restauradas. Se examinaron las distribuciones de frecuencia de tamaño y clase para los Escleractinios más abundantes, lo que mostró que las áreas restauradas están convergiendo con las de referencia. Para los Escleractinios, también se presentan números y porcentajes de colonias por especie al igual que varios índices comunes de biodiversidad. Las medidas para el área restaurada se aproximan al área de referencia. Una comparación cuantitativa del sustrato preferido para el asentamiento de las colonias en el área de restauración se presenta para todos los Órdenes; para el caso de Escleractinios se presenta más detalle de los dos géneros más frecuentes.
Asunto(s)
Animales , Antozoos/clasificación , Biodiversidad , Arrecifes de Coral , Conservación de los Recursos Naturales/métodos , Monitoreo del Ambiente/métodos , Accidentes , Tormentas Ciclónicas , Florida , Densidad de Población , Dinámica Poblacional , NavíosRESUMEN
This study describes the severity of the 2005 bleaching event at 15 reef sites across Venezuela and compares the 1998 and 2005 bleaching events at one of them. During August and September 2005, bleached corals were first observed on oceanic reefs rather than coastal reefs, affecting 1 to 4% of coral colonies in the community (3 reef sites, n=736 colonies). At that time, however, no bleached corals were recorded along the eastern coast of Venezuela, an area of seasonal upwelling (3 reefs, n=181 colonies). On coastal reefs, bleaching started in October but highest levels were reached in November 2005 and January 2006, when 16% of corals were affected among a wide range of taxa (e.g. scleractinians, octocorals, Millepora and zoanthids). In the Acropora habitats of Los Roques (an oceanic reef), no bleached was recorded in 2005 (four sites, n=643 colonies). At Cayo Sombrero, a coastal reef site, bleaching was less severe in 1998 than in 2005 (9% of the coral colonies involving 2 species vs. 26% involving 23 species, respectively). Our results indicate that bleaching was more severe in 2005 than in 1998 on Venezuelan reefs; however, no mass mortality was observed in either of these two events. Rev. Biol. Trop. 58 (Suppl. 3): 189-196. Epub 2010 October 01.
En este estudio se describe la severidad del evento de blanqueamiento del 2005 en 15 arrecifes coralinos de Venezuela, y se compara con el ocurrido en 1998 para uno de esos arrecifes. Los primeros corales blanqueados se observaron en agosto y septiembre 2005, en arrecifes oceánicos en lugar de costeros, afectando entre 1 y 4% de las colonias coralinas (3 arrecifes, n= 736 colonias). Para ese momento, tampoco se había detectado blanqueamiento en áreas oceánicas de la costa este de Venezuela (3 arrecifes, n= 181 colonias), donde ocurre una surgencia estacional. En arrecifes costeros, el blanqueamiento comenzó en octubre pero alcanzó su máximo entre noviembre 2005 y enero 2006, afectando hasta el 16% de los organismos de una variedad de taxa (e.g. escleractinios, octocorales, Millepora, zoántidos). En los hábitats de Acropora de Los Roques, no se observó blanqueamiento en el 2005 (4 sitios oceánicos, n= 643 colonias). En Cayo Sombrero, un arrecife costero, el blanqueamiento fue menos severo en 1998 comparado con el de 2005 (9% de colonias coralinas de 2 especies vs. 26% de colonias de 23 especies, respectivamente).Estos resultados indican que el blanqueamiento del 2005 fue más severo que el de 1998 en los arrecifes de Venezuela, sin embargo, no ocurrió mortalidad masiva asociada a ninguno de los dos eventos.
Asunto(s)
Animales , Antozoos , Pigmentación , Antozoos/clasificación , Monitoreo del Ambiente , Mortalidad , Dinámica Poblacional , Agua de Mar , VenezuelaRESUMEN
The main goal of this research was to obtain baseline field data of the composition of sponges, corals, and gorgonian assemblages that can be used as a reference for future analyses of anthropogenic impact. We tested the hypothesis that relatively homogeneous and well preserved reef units can present notable natural variability in the composition of their communities which are unassociated with changes in land proximity or a human impact gradient. Research was carried out in July 2006 at Los Colorados reef, located in the northwestern region of Pinar del Río Province, Cuba at 12 sampling stations. The biotopes selected were crest, terrace edge and spur and grove. Ecological indicators were diversity of corals, species composition, density of corals, hydrocorals, gorgonians and sponges, and density of selected coral species. A total of 2659 colonies of scleractineans corals representing 36 species were counted. The most abundant species in the crest biotope were Millepora alcicornis, Acropora palmata and Porites astreoides; in the terrace edge and spur and grove, the most abundant species were Siderastrea siderea, Stephanocoenia intersepta, Porites astreoides, Agaricia agaricites and Montastraea cavernosa. We found differences among sites for several indicators (e.g. density of corals, sponges and gorgonians and for selected species), but they could not be associated to any gradient of land influence or human impact. Therefore, sites inside a relatively homogeneous reef unit can present notable natural differences in the composition of their communities. Rev. Biol. Trop. 58 (2): 621-634. Epub 2010 June 02.
El objetivo principal de la investigación fue obtener una línea base de la composición de las comunidades de esponjas, corales y gorgonias que pueda ser utilizada como referencia para futuros análisis de impacto antrópico. Nuestra hipótesis es que un arrecife relativamente homogéneo y bien conservado, presenta una variabilidad natural notable en la composición de sus comunidades, lo cual no está asociado con cambios en la proximidad a tierra o a un gradiente de impacto humano. La investigación se llevó a cabo en julio de 2006, en 12 estaciones de muestreo ubicadas en el arrecife de Los Colorados, en la región noroccidental de la Provincia de Pinar del Río, Cuba. Los biotopos seleccionados fueron cresta, veril y camellones. Los indicadores ecológicos estimados fueron: diversidad de corales, composición por especies, densidad de corales, hidrocorales, gorgonias y esponjas, y densidad de especies de corales seleccionadas. Se contaron 2 659 colonias de corales escleractíneos pertenecientes a 36 especies. Las especies más abundantes en el biotopo de cresta fueron: Millepora alcicornis, Acropora palmata y Porites astreoides; mientras que en el veril y los camellones fueron Siderastrea siderea, Stephanocoenia intersepta, Porites astreoides, Agaricia agaricites y Montastraea cavernosa. Entre sitios, se encontraron diferencias significativas estadísticamente para varios indicadores (densidad de corales, esponjas y gorgonias y densidad de especies seleccionadas), pero ello no pudo asociarse con ningún gradiente de uso de la tierra o de impacto humano. Por lo tanto, sitios dentro de un arrecife relativamente homogéneo pueden presentar diferencias notables en la composición de sus comunidades.