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1.
PeerJ ; 12: e17829, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39099657

RESUMEN

Over the past few decades, corals of the genus Tubastraea have spread globally, revealing themselves to be organisms of great invasive capacity. Their constant expansion on the Brazilian coast highlights the need for studies to monitor the invasion process. The growth, fecundity, settlement, and data on the coverage area of three co-occurring Tubastraea species in the 2015-2016 period were related to temperature variation and light irradiance on the rocky shores of Arraial do Cabo, Rio de Janeiro. Hence, this study sought to understand and compare the current invasion scenario and characteristics of the life history strategy of sun coral species based on environmental variables, considering the uniqueness of this upwelling area in the southwestern Atlantic. For that, we evaluate the fecundity, settlement, and growth rates of corals by carrying out comparative studies between species over time and correlating them with the variables temperature and irradiance, according to seasonality. Field growth of colonies was measured every two months during a sample year. Monthly collections were performed to count reproductive oocytes to assess fecundity. Also, quadrats were scrapped from an area near a large patch of sun coral to count newly attached coral larvae and used years later to assess diversity and percentage coverage. Results showed that corals presented greater growth during periods of high thermal amplitude and in months with below-average temperatures. Only Tubastraea sp. had greater growth and polyp increase in areas with higher light incidence, showing a greater increase in total area compared to all the other species analyzed. Despite the observed affinity with high temperatures, settlement rates were also higher during the same periods. Months with low thermal amplitude and higher temperature averages presented high fecundity. While higher water temperature averages showed an affinity with greater coral reproductive activity, growth has been shown to be inversely proportional to reproduction. Our study recorded the most significant coral growth for the region, an increase in niche, high annual reproductive activity, and large area coverage, showing the ongoing adaptation of the invasion process in the region. However, lower temperatures in the region affect these corals' reproductive activity and growth, slowing down the process of introduction into the region. To better understand the advantages of these invasion strategies in the environment, we must understand the relationships between them and the local community that may be acting to slow down this colonization process.


Asunto(s)
Antozoos , Fertilidad , Animales , Antozoos/crecimiento & desarrollo , Antozoos/fisiología , Fertilidad/fisiología , Brasil , Especies Introducidas , Temperatura , Arrecifes de Coral , Estaciones del Año , Océano Atlántico , Rasgos de la Historia de Vida , Reproducción/fisiología
2.
PLoS One ; 19(7): e0303779, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39083457

RESUMEN

Climate change is transforming coral reefs by increasing the frequency and intensity of marine heatwaves, often leading to coral bleaching and mortality. Coral communities have demonstrated modest increases in thermal tolerance following repeated exposure to moderate heat stress, but it is unclear whether these shifts represent acclimatization of individual colonies or mortality of thermally susceptible individuals. For corals that survive repeated bleaching events, it is important to understand how past bleaching responses impact future growth potential. Here, we track the bleaching responses of 1,832 corals in leeward Maui through multiple marine heatwaves and document patterns of coral growth and survivorship over a seven-year period. While we find limited evidence of acclimatization at population scales, we document reduced bleaching over time in specific individuals that is indicative of acclimatization, primarily in the stress-tolerant taxa Porites lobata. For corals that survived both bleaching events, we find no relationship between bleaching response and coral growth in three of four taxa studied. This decoupling suggests that coral survivorship is a better indicator of future growth than is a coral's bleaching history. Based on these results, we recommend restoration practitioners in Hawai'i focus on colonies of Porites and Montipora with a proven track-record of growth and survivorship, rather than devote resources toward identifying and cultivating bleaching-resistant phenotypes in the lab. Survivorship followed a latitudinal thermal stress gradient, but because this gradient was small, it is likely that local environmental factors also drove differences in coral performance between sites. Efforts to reduce human impacts at low performing sites would likely improve coral survivorship in the future.


Asunto(s)
Aclimatación , Antozoos , Cambio Climático , Arrecifes de Coral , Antozoos/fisiología , Antozoos/crecimiento & desarrollo , Animales , Aclimatación/fisiología , Blanqueamiento de los Corales , Respuesta al Choque Térmico/fisiología , Hawaii , Calor/efectos adversos
3.
PLoS One ; 19(6): e0292474, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38923956

RESUMEN

The effects of turbidity and sedimentation stress on early life stages of corals are poorly understood, particularly in Atlantic species. Dredging operations, beach nourishment, and other coastal construction activities can increase sedimentation and turbidity in nearby coral reef habitats and have the potential to negatively affect coral larval development and metamorphosis, reducing sexual reproduction success. In this study, we investigated the performance of larvae of the threatened Caribbean coral species Orbicella faveolata exposed to suspended sediments collected from a reef site in southeast Florida recently impacted by dredging (Port of Miami), and compared it to the performance of larvae exposed to sediments collected from the offshore, natal reef of the parent colonies. In a laboratory experiment, we tested whether low and high doses of each of these sediment types affected the survival, settlement, and respiration of coral larvae compared to a no-sediment control treatment. In addition, we analyzed the sediments used in the experiments with 16S rRNA gene amplicon sequencing to assess differences in the microbial communities present in the Port versus Reef sediments, and their potential impact on coral performance. Overall, only O. faveolata larvae exposed to the high-dose Port sediment treatment had significantly lower survival rates compared to the control treatment, suggesting an initial tolerance to elevated suspended sediments. However, significantly lower settlement rates were observed in both Port treatments (low- and high-dose) compared to the control treatment one week after exposure, suggesting strong latent effects. Sediments collected near the Port also contained different microbial communities than Reef sediments, and higher relative abundances of the bacteria Desulfobacterales, which has been associated with coral disease. We hypothesize that differences in microbial communities between the two sediments may be a contributing factor in explaining the observed differences in larval performance. Together, these results suggest that the settlement success and survival of O. faveolata larvae are more readily compromised by encountering port inlet sediments compared to reef sediments, with potentially important consequences for the recruitment success of this species in affected areas.


Asunto(s)
Antozoos , Arrecifes de Coral , Sedimentos Geológicos , Larva , Animales , Antozoos/crecimiento & desarrollo , Antozoos/microbiología , Antozoos/fisiología , Larva/crecimiento & desarrollo , Sedimentos Geológicos/microbiología , Especies en Peligro de Extinción , ARN Ribosómico 16S/genética , Florida , Microbiota
4.
Mar Environ Res ; 198: 106534, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38744166

RESUMEN

In the context of ocean warming, thermophilic organisms such as zoantharians are expanding and altering shallow benthic habitats. Here, a four-month laboratory experiment was performed to examine the influence of three types of macroalgae morphotypes common in the Canary Islands (turf algae, Lobophora spp., and crustose coralline algae) on the growth of two zoantharian species, Palythoa caribaeorum and Zoanthus pulchellus. Additionally, the grazing effects of echinoids Diadema africanum and Paracentrotus lividus were assessed as facilitators of substrate colonization by means of controlling macroalgae cover. Colony and algal coverages were measured at the beginning, middle and end of the experiment, and increments were calculated. Results indicated a general decrease in zoantharian colony sizes in contact with different algal types in the absence of sea urchins. However, P. caribaeorum colonies showed significant growth in the presence of D. africanum, highlighting the ecological importance of sea urchins in zoantharian population proliferation and subsequent community modification. This study represents the first investigation into zoantharian-macroalgae interactions under controlled conditions.


Asunto(s)
Erizos de Mar , Algas Marinas , Animales , Erizos de Mar/fisiología , Erizos de Mar/crecimiento & desarrollo , Algas Marinas/fisiología , Algas Marinas/crecimiento & desarrollo , Antozoos/fisiología , Antozoos/crecimiento & desarrollo , Ecosistema , Herbivoria , España
5.
Sci Rep ; 14(1): 9817, 2024 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-38684737

RESUMEN

Mutualism profoundly affects the morphology and ecological evolution of both hosts and symbionts involved. Heterocyathus is a solitary scleractinian coral that lives on soft substrata, and sipunculan worms live symbiotically in the tube-like cavities (orifice) inside the coral skeletons. This habitat provides protection to the sipunculan worms against predators and-owing to the mobility of the worms-prevents the coral from being buried with sediments. The orifice growth is closely related to the symbiont sipunculan worms; however, this has not been previously elucidated. Here, we clarified the growth process of scleractinian coral orifices and the influence of sipunculan activity on this. The orifices were originally formed by rapid accretion deposits. The coral soft tissue enveloping the growth edge of the orifice repeatedly retreated to the outer side due to direct damage to the soft part and/or excessive stress caused by the rubbing of the sipunculan through locomotion, excretion, and feeding behaviour. This resulted in a toppled-domino microskeletal structure appearance and maintenance of the orifice growth. These outcomes demonstrate the first example of the direct influence of symbionts on the skeletal morphogenesis of scleractinian corals. The mutualism between the two organisms is maintained by the beneficial confrontation in forming orifices.


Asunto(s)
Antozoos , Simbiosis , Animales , Antozoos/fisiología , Antozoos/crecimiento & desarrollo , Simbiosis/fisiología , Adaptación Fisiológica , Ecosistema , Arrecifes de Coral
6.
J Exp Biol ; 227(9)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38634316

RESUMEN

Body size profoundly affects organism fitness and ecosystem dynamics through the scaling of physiological traits. This study tested for variation in metabolic scaling and its potential drivers among corals differing in life history strategies and taxonomic identity. Data were compiled from published sources and augmented with empirical measurements of corals in Moorea, French Polynesia. The data compilation revealed metabolic isometry in broadcasted larvae, but size-independent metabolism in brooded larvae; empirical measurements of Pocillopora acuta larvae also supported size-independent metabolism in brooded coral larvae. In contrast, for juvenile colonies (i.e. 1-4 cm diameter), metabolic scaling was isometric for Pocillopora spp., and negatively allometric for Porites spp. The scaling of biomass with surface area was isometric for Pocillopora spp., but positively allometric for Porites spp., suggesting the surface area to biomass ratio mediates metabolic scaling in these corals. The scaling of tissue biomass and metabolism were not affected by light treatment (i.e. either natural photoperiods or constant darkness) in either juvenile taxa. However, biomass was reduced by 9-15% in the juvenile corals from the light treatments and this coincided with higher metabolic scaling exponents, thus supporting the causal role of biomass in driving variation in scaling. This study shows that metabolic scaling is plastic in early life stages of corals, with intrinsic differences between life history strategy (i.e. brooded and broadcasted larvae) and taxa (i.e. Pocillopora spp. and Porites spp.), and acquired differences attributed to changes in area-normalized biomass.


Asunto(s)
Antozoos , Biomasa , Tamaño Corporal , Larva , Animales , Antozoos/metabolismo , Antozoos/fisiología , Antozoos/crecimiento & desarrollo , Larva/crecimiento & desarrollo , Larva/metabolismo , Larva/fisiología , Polinesia
7.
Nature ; 620(7976): 1018-1024, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37612503

RESUMEN

Coral reefs are highly diverse ecosystems that thrive in nutrient-poor waters, a phenomenon frequently referred to as the Darwin paradox1. The energy demand of coral animal hosts can often be fully met by the excess production of carbon-rich photosynthates by their algal symbionts2,3. However, the understanding of mechanisms that enable corals to acquire the vital nutrients nitrogen and phosphorus from their symbionts is incomplete4-9. Here we show, through a series of long-term experiments, that the uptake of dissolved inorganic nitrogen and phosphorus by the symbionts alone is sufficient to sustain rapid coral growth. Next, considering the nitrogen and phosphorus budgets of host and symbionts, we identify that these nutrients are gathered through symbiont 'farming' and are translocated to the host by digestion of excess symbiont cells. Finally, we use a large-scale natural experiment in which seabirds fertilize some reefs but not others, to show that the efficient utilization of dissolved inorganic nutrients by symbiotic corals established in our laboratory experiments has the potential to enhance coral growth in the wild at the ecosystem level. Feeding on symbionts enables coral animals to tap into an important nutrient pool and helps to explain the evolutionary and ecological success of symbiotic corals in nutrient-limited waters.


Asunto(s)
Antozoos , Ecosistema , Nitrógeno , Fósforo , Fotosíntesis , Simbiosis , Animales , Antozoos/crecimiento & desarrollo , Antozoos/metabolismo , Antozoos/fisiología , Nitrógeno/metabolismo , Fósforo/metabolismo , Simbiosis/fisiología , Aves/fisiología
8.
Mar Environ Res ; 179: 105686, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35779402

RESUMEN

Savalia savaglia is an ecosystem engineer listed as Near-Threatened by the IUCN, even though effective management and proper monitoring efforts to assess its distribution is still lacking. The record of large, long-established colonies can indicate the occurrence of areas with limited human local pressure. These areas may be considered as proxies for the creation of baselines of reference useful to design restoration strategies. The aim of this work was to update the distribution of S. savaglia Mediterranean populations to develop an Ecological Niche Model, highlighting potential areas for future monitoring programs. Occurrence data were collected and harmonized into a single dataset using the scientific literature and validated observations to feed a presence-only MaxEnt model, obtaining a basin-level potential distribution of the species. The results of our study can support decision-makers in marine spatial planning measures including the preservation of mesophotic environments and prioritizing areas for conservation.


Asunto(s)
Antozoos/crecimiento & desarrollo , Monitoreo Biológico/métodos , Conservación de los Recursos Naturales , Animales , Antozoos/clasificación , Biodiversidad , Ecosistema , Especies en Peligro de Extinción , Humanos , Mar Mediterráneo , Modelos Biológicos
9.
PLoS One ; 17(2): e0263061, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35192627

RESUMEN

Cold-water coral (CWC) reefs are numerous and widespread along the Norwegian continental shelf where oil and gas industry operate. Uncertainties exist regarding their impacts from operational discharges to drilling. Effect thresholds obtained from near-realistic exposure of suspended particle concentrations for use in coral risk modeling are particularly needed. Here, nubbins of Desmophyllum pertusum (Lophelia pertusa) were exposed shortly (5 days, 4h repeated pulses) to suspended particles (bentonite BE; barite BA, and drill cuttings DC) in the range of ~ 4 to ~ 60 mg.l-1 (actual concentration). Physiological responses (respiration rate, growth rate, mucus-related particulate organic carbon OC and particulate organic nitrogen ON) and polyp mortality were then measured 2 and 6 weeks post-exposure to assess long-term effects. Respiration and growth rates were not significantly different in any of the treatments tested compared to control. OC production was not affected in any treatment, but a significant increase of OC:ON in mucus produced by BE-exposed (23 and 48 mg.l-1) corals was revealed 2 weeks after exposure. Polyp mortality increased significantly at the two highest DC doses (19 and 49 mg.l-1) 2 and 6 weeks post-exposure but no significant difference was observed in any of the other treatments compared to the control. These findings are adding new knowledge on coral resilience to short realistic exposure of suspended drill particles and indicate overall a risk for long-term effects at a threshold of ~20 mg.l-1.


Asunto(s)
Adaptación Fisiológica , Antozoos/efectos de los fármacos , Sulfato de Bario/farmacología , Bentonita/farmacología , Material Particulado/farmacología , Frecuencia Respiratoria/efectos de los fármacos , Animales , Antozoos/crecimiento & desarrollo , Carbono/química , Carbono/metabolismo , Arrecifes de Coral , Industria Procesadora y de Extracción/métodos , Humanos , Longevidad/efectos de los fármacos , Nitrógeno/química , Nitrógeno/metabolismo , Noruega , Frecuencia Respiratoria/fisiología , Agua/química
10.
Proc Natl Acad Sci U S A ; 119(5)2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-35101918

RESUMEN

Metabolites exuded by primary producers comprise a significant fraction of marine dissolved organic matter, a poorly characterized, heterogenous mixture that dictates microbial metabolism and biogeochemical cycling. We present a foundational untargeted molecular analysis of exudates released by coral reef primary producers using liquid chromatography-tandem mass spectrometry to examine compounds produced by two coral species and three types of algae (macroalgae, turfing microalgae, and crustose coralline algae [CCA]) from Mo'orea, French Polynesia. Of 10,568 distinct ion features recovered from reef and mesocosm waters, 1,667 were exuded by producers; the majority (86%) were organism specific, reflecting a clear divide between coral and algal exometabolomes. These data allowed us to examine two tenets of coral reef ecology at the molecular level. First, stoichiometric analyses show a significantly reduced nominal carbon oxidation state of algal exometabolites than coral exometabolites, illustrating one ecological mechanism by which algal phase shifts engender fundamental changes in the biogeochemistry of reef biomes. Second, coral and algal exometabolomes were differentially enriched in organic macronutrients, revealing a mechanism for reef nutrient-recycling. Coral exometabolomes were enriched in diverse sources of nitrogen and phosphorus, including tyrosine derivatives, oleoyl-taurines, and acyl carnitines. Exometabolites of CCA and turf algae were significantly enriched in nitrogen with distinct signals from polyketide macrolactams and alkaloids, respectively. Macroalgal exometabolomes were dominated by nonnitrogenous compounds, including diverse prenol lipids and steroids. This study provides molecular-level insights into biogeochemical cycling on coral reefs and illustrates how changing benthic cover on reefs influences reef water chemistry with implications for microbial metabolism.


Asunto(s)
Antozoos/metabolismo , Materia Orgánica Disuelta/análisis , Algas Marinas/metabolismo , Animales , Antozoos/genética , Antozoos/crecimiento & desarrollo , Carbono/metabolismo , Arrecifes de Coral , Ecosistema , Biología Marina/métodos , Metabolómica/métodos , Nitrógeno/metabolismo , Nutrientes , Fósforo/metabolismo , Polinesia , Agua de Mar/química , Algas Marinas/genética , Algas Marinas/crecimiento & desarrollo
11.
PLoS One ; 16(12): e0258725, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34910721

RESUMEN

Small cryptic invertebrates (the cryptofauna) are extremely abundant, ecologically important, and species rich on coral reefs. Ongoing ocean acidification is likely to have both direct effects on the biology of these organisms, as well as indirect effects through cascading impacts on their habitats and trophic relationships. Naturally acidified habitats have been important model systems for studying these complex interactions because entire communities that are adapted to these environmental conditions can be analyzed. However, few studies have examined the cryptofauna because they are difficult to census quantitatively in topographically complex habitats and are challenging to identify. We addressed these challenges by using Autonomous Reef Monitoring Structures (ARMS) for sampling reef-dwelling invertebrates >2 mm in size and by using DNA barcoding for taxonomic identifications. The study took place in Papua New Guinea at two reef localities, each with three sites at varying distances from carbon dioxide seeps, thereby sampling across a natural gradient in acidification. We observed sharp overall declines in both the abundance (34-56%) and diversity (42-45%) of organisms in ARMS under the lowest pH conditions sampled (7.64-7.75). However, the overall abundance of gastropods increased slightly in lower pH conditions, and crustacean and gastropod families exhibited varying patterns. There was also variability in response between the two localities, despite their close proximity, as one control pH site displayed unusually low diversity and abundances for all invertebrate groups. The data illustrate the complexity of responses of the reef fauna to pH conditions, and the role of additional factors that influence the diversity and abundance of cryptic reef invertebrates.


Asunto(s)
Antozoos , Biodiversidad , Dióxido de Carbono/análisis , Crustáceos , Gastrópodos , Agua de Mar/análisis , Animales , Antozoos/clasificación , Antozoos/genética , Antozoos/crecimiento & desarrollo , Arrecifes de Coral , Crustáceos/clasificación , Crustáceos/genética , Crustáceos/crecimiento & desarrollo , Código de Barras del ADN Taxonómico , Gastrópodos/clasificación , Gastrópodos/genética , Gastrópodos/crecimiento & desarrollo , Concentración de Iones de Hidrógeno , Papúa Nueva Guinea
12.
PLoS One ; 16(12): e0260516, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34874982

RESUMEN

Coral recruitment and successive growth are essential for post-disturbance reef recovery. As coral recruit and juvenile abundances vary across locations and under different environmental regimes, their assessment at remote, undisturbed reefs improves our understanding of early life stage dynamics of corals. Here, we first explored changes in coral juvenile abundance across three locations (lagoon, seaward west and east) at remote Aldabra Atoll (Seychelles) between 2015 and 2019, which spanned the 2015/16 global coral bleaching event. Secondly, we measured variation in coral recruit abundance on settlement tiles from two sites (lagoon, seaward reef) during August 2018-August 2019. Juvenile abundance decreased from 14.1 ± 1.2 to 7.4 ± 0.5 colonies m-2 (mean ± SE) during 2015-2016 and increased to 22.4 ± 1.2 colonies m-2 during 2016-2019. Whilst juvenile abundance increased two- to three-fold at the lagoonal and seaward western sites during 2016-2018 (from 7.7-8.3 to 17.3-24.7 colonies m-2), increases at the seaward eastern sites occurred later (2018-2019; from 5.8-6.9 to 16.6-24.1 colonies m-2). The composition of coral recruits on settlement tiles was dominated by Pocilloporidae (64-92% of all recruits), and recruit abundance was 7- to 47-fold higher inside than outside the lagoon. Recruit abundance was highest in October-December 2018 (2164 ± 453 recruits m-2) and lowest in June-August 2019 (240 ± 98 recruits m-2). As Acroporid recruit abundance corresponded to this trend, the results suggest that broadcast spawning occurred during October-December, when water temperature increased from 26 to 29°C. This study provides the first published record on coral recruit abundance in the Seychelles Outer Islands, indicates a rapid (2-3 years) increase of juvenile corals following a bleaching event, and provides crucial baseline data for future research on reef resilience and connectivity within the region.


Asunto(s)
Antozoos/clasificación , Antozoos/crecimiento & desarrollo , Animales , Blanqueamiento de los Corales/prevención & control , Blanqueamiento de los Corales/estadística & datos numéricos , Arrecifes de Coral , Calentamiento Global , Filogenia , Seychelles
13.
Sci Rep ; 11(1): 22554, 2021 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-34799589

RESUMEN

Chimerism is a coalescence of conspecific genotypes. Although common in nature, fundamental knowledge, such as the spatial distribution of the genotypes within chimeras, is lacking. Hence, we investigated the spatial distribution of conspecific genotypes within the brooding coral Stylophora pistillata, a common species throughout the Indo-Pacific and Red Sea. From eight gravid colonies, we collected planula larvae that settled in aggregates, forming 2-3 partner chimeras. Coral chimeras grew in situ for up to 25 months. Nine chimeras (8 kin, 1 non-related genotypes) were sectioned into 7-17 fragments (6-26 polyps/fragment), and genotyped using eight microsatellite loci. The discrimination power of each microsatellite-locus was evaluated with 330 'artificial chimeras,' made by mixing DNA from three different S. pistillata genotypes in pairwise combinations. In 68% of 'artificial chimeras,' the second genotype was detected if it constituted 5-30% of the chimera. Analyses of S. pistillata chimeras revealed that: (a) chimerism is a long-term state; (b) conspecifics were intermixed (not separate from one another); (c) disproportionate distribution of the conspecifics occurred; (d) cryptic chimerism (chimerism not detected via a given microsatellite) existed, alluding to the underestimation of chimerism in nature. Mixed chimerism may affect ecological/physiological outcomes for a chimera, especially in clonal organisms, and challenges the concept of individuality, affecting our understanding of the unit of selection.


Asunto(s)
Antozoos/genética , Quimerismo , Repeticiones de Microsatélite , Animales , Antozoos/crecimiento & desarrollo , Evolución Molecular , Genotipo
14.
PLoS One ; 16(9): e0257523, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34587221

RESUMEN

Heterocorals represent an enigmatic group of Palaeozoic corals, known from relatively short time intervals in the Devonian and Carboniferous periods. The major differences between Heterocorallia and other Palaeozoic corals are the lack of an external theca (epitheca), lack of calices and the presence of dichotomously dividing septa-like structures. Heterocoral skeleton was presumably externally covered by the soft tissue and each branch of their skeleton has, until now, been regarded as a corallite-a skeleton of a single polyp. We investigated upper Famennian Oligophylloides from Morocco, focussing on branching processes, wall structure, previously poorly known initial growth stages and the growing tip, described here for the first time. We demonstrate that Oligophylloides shows a unique colony development not known in any group of anthozoans possessing a septate-like architecture and suggest that the previously postulated homology between true septa in hexa- and rugose corals on one hand, and Oligophylloides on the other, must be rejected. Based on the skeleton structure and branching patterns, we postulate, contrary to former ideas, that the stem and branches of heterocorals represent the skeleton of a multi-polyp colonial coral, similar to many extant octocorals. We found numerous potential homologies with octocoral skeletons (notably the Keratoisidinae within the Isididae) and, as a result, we propose the inclusion of the order Heterocorallia within the subclass Octocorallia. This suggestion requires, however, further research on the other taxa of heterocorals. We also propose some changes to the morphological terminology for the Heterocorallia.


Asunto(s)
Antozoos/anatomía & histología , Animales , Antozoos/clasificación , Antozoos/crecimiento & desarrollo , Marruecos , Filogenia , Filogeografía
15.
PLoS One ; 16(9): e0250725, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34499664

RESUMEN

Cumulative anthropogenic stressors on tropical reefs are modifying the physical and community structure of coral assemblages, altering the rich biological communities that depend on this critical habitat. As a consequence, new reef configurations are often characterized by low coral cover and a shift in coral species towards massive and encrusting corals. Given that coral numbers are dwindling in these new reef systems, it is important to evaluate the potential influence of coral predation on these remaining corals. We examined the effect of a key group of coral predators (parrotfishes) on one of the emerging dominant coral taxa on Anthropocene reefs, massive Porites. Specifically, we evaluate whether the intensity of parrotfish predation on this key reef-building coral has changed in response to severe coral reef degradation. We found evidence that coral predation rates may have decreased, despite only minor changes in parrotfish abundance. However, higher scar densities on small Porites colonies, compared to large colonies, suggests that the observed decrease in scarring rates may be a reflection of colony-size specific rates of feeding scars. Reduced parrotfish corallivory may reflect the loss of small Porites colonies, or changing foraging opportunities for parrotfishes. The reduction in scar density on massive Porites suggests that the remaining stress-tolerant corals may have passed the vulnerable small colony stage. These results highlight the potential for shifts in ecological functions on ecosystems facing high levels of environmental stress.


Asunto(s)
Antozoos/crecimiento & desarrollo , Peces/fisiología , Animales , Antozoos/parasitología , Arrecifes de Coral , Dinámica Poblacional , Conducta Predatoria
16.
J Struct Biol ; 213(4): 107782, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34455069

RESUMEN

Despite their simple body plan, stony corals (order Scleractinia, phylum Cnidaria) can produce massive and complex exoskeletal structures in shallow, tropical and subtropical regions of Earth's oceans. The species-specific macromorphologies of their aragonite skeletons suggest a highly coordinated biomineralization process that is rooted in their genomes, and which has persisted across major climatic shifts over the past 400 + million years. The mechanisms by which stony corals produce their skeletons has been the subject of interest for at least the last 160 years, and the pace of understanding the process has increased dramatically in the past decade since the sequencing of the first coral genome in 2011. In this review, we detail what is known to date about the genetic basis of the stony coral biomineralization process, with a focus on advances in the last several years as well as ways that physical and chemical tools can be combined with genetics, and then propose next steps forward for the coming decade.


Asunto(s)
Antozoos/genética , Biomineralización/genética , Calcificación Fisiológica/genética , Metamorfosis Biológica/genética , Animales , Antozoos/clasificación , Antozoos/crecimiento & desarrollo , Carbonato de Calcio/metabolismo , Epigenómica/métodos , Epigenómica/tendencias , Predicción , Edición Génica/métodos , Edición Génica/tendencias , Larva/genética , Larva/crecimiento & desarrollo , Larva/metabolismo , Filogenia , Especificidad de la Especie
17.
Elife ; 102021 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-34387190

RESUMEN

Climate change is dramatically changing ecosystem composition and productivity, leading scientists to consider the best approaches to map natural resistance and foster ecosystem resilience in the face of these changes. Here, we present results from a large-scale experimental assessment of coral bleaching resistance, a critical trait for coral population persistence as oceans warm, in 221 colonies of the coral Acropora hyacinthus across 37 reefs in Palau. We find that bleaching-resistant individuals inhabit most reefs but are found more often in warmer microhabitats. Our survey also found wide variation in symbiont concentration among colonies, and that colonies with lower symbiont load tended to be more bleaching-resistant. By contrast, our data show that low symbiont load comes at the cost of lower growth rate, a tradeoff that may operate widely among corals across environments. Corals with high bleaching resistance have been suggested as a source for habitat restoration or selective breeding in order to increase coral reef resilience to climate change. Our maps show where these resistant corals can be found, but the existence of tradeoffs with heat resistance may suggest caution in unilateral use of this one trait in restoration.


Asunto(s)
Antozoos/crecimiento & desarrollo , Antozoos/parasitología , Arrecifes de Coral , Variación Genética , Calentamiento Global , Simbiosis , Termotolerancia , Animales , Antozoos/genética , Clorofila/análisis , Conservación de los Recursos Naturales , Palau , Simbiosis/genética , Termotolerancia/genética
18.
Sci Rep ; 11(1): 13165, 2021 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-34162916

RESUMEN

Coral reefs, especially those located near-shore, are increasingly exposed to anthropogenic, eutrophic conditions that are often chronic. Yet, corals under unperturbed conditions may frequently receive natural and usually temporary nutrient supplementation through biological sources such as fishes. We compared physiological parameters indicative of long- and short-term coral health (day and night calcification, fragment surface area, productivity, energy reserves, and tissue stoichiometry) under continuous and temporary nutrient enrichment. The symbiotic coral Acropora intermedia was grown for 7 weeks under continuously elevated (press) levels of ammonium (14 µmol L-1) and phosphate (10 µmol L-1) as separate and combined treatments, to discern the individual and interactive nutrient effects. Another treatment exposed A. intermedia twice-daily to an ammonium and phosphate pulse of the same concentrations as the press treatments to simulate natural biotic supplementation. Press exposure to elevated ammonium or phosphate produced mixed effects on physiological responses, with little interaction between the nutrients in the combined treatment. Overall, corals under press exposure transitioned resources away from calcification. However, exposure to nutrient pulses often enhanced physiological responses. Our findings indicate that while continuous nutrient enrichment may pose a threat to coral health, episodic nutrient pulses that resemble natural nutrient supplementation may significantly benefit coral health and physiology.


Asunto(s)
Compuestos de Amonio/farmacología , Antozoos/efectos de los fármacos , Fosfatos/farmacología , Compuestos de Amonio/administración & dosificación , Animales , Antozoos/crecimiento & desarrollo , Antozoos/metabolismo , Calcificación Fisiológica/efectos de los fármacos , Ritmo Circadiano , Fosfatos/administración & dosificación , Fotosíntesis , Distribución Aleatoria , Agua de Mar
19.
Sci Rep ; 11(1): 12833, 2021 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-34172760

RESUMEN

Global climate change is a major threat to reefs by increasing the frequency and severity of coral bleaching events over time, reducing coral cover and diversity. Ocean warming may cause shifts in coral communities by increasing temperatures above coral's upper thermal limits in tropical regions, and by making extratropical regions (marginal reefs) more suitable and potential refugia. We used Bayesian models to project coral occurrence, cover and bleaching probabilities in Southwestern Atlantic and predicted how these probabilities will change under a high-emission scenario (RCP8.5). By overlapping these projections, we categorized areas that combine high probabilities of coral occurrence, cover and bleaching as vulnerability-hotspots. Current coral occurrence and cover probabilities were higher in the tropics (1°S-20°S) but both will decrease and shift to new suitable extratropical reefs (20°S-27°S; tropicalization) with ocean warming. Over 90% of the area present low and mild vulnerability, while the vulnerability-hotspots represent ~ 3% under current and future scenarios, but include the most biodiverse reef complex in South Atlantic (13°S-18°S; Abrolhos Bank). As bleaching probabilities increase with warming, the least vulnerable areas that could act as potential refugia are predicted to reduce by 50%. Predicting potential refugia and highly vulnerable areas can inform conservation actions to face climate change.


Asunto(s)
Antozoos/crecimiento & desarrollo , Cambio Climático , Ecosistema , Calentamiento Global , Animales , Océano Atlántico , Arrecifes de Coral , Agua de Mar , Temperatura
20.
Sci Rep ; 11(1): 12525, 2021 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-34108494

RESUMEN

Ocean warming, fueled by climate change, is the primary cause of coral bleaching events which are predicted to increase in frequency. Bleaching is generally damaging to coral reproduction, can be exacerbated by concomitant stressors like ultraviolet radiation (UVR), and can have lasting impacts to successful reproduction and potential adaptation. We compared morphological and physiological reproductive metrics (e.g., sperm motility, mitochondrial membrane integrity, egg volume, gametes per bundle, and fertilization and settlement success) of two Hawaiian Montipora corals after consecutive bleaching events in 2014 and 2015. Between the species, sperm motility and mitochondrial membrane potential had the most disparate results. Percent sperm motility in M. capitata, which declined to ~ 40% during bleaching from a normal range of 70-90%, was still less than 50% motile in 2017 and 2018 and had not fully recovered in 2019 (63% motile). By contrast, percent sperm motility in Montipora spp. was 86% and 74% in 2018 and 2019, respectively. This reduction in motility was correlated with damage to mitochondria in M. capitata but not Montipora spp. A major difference between these species is the physiological foundation of their UVR protection, and we hypothesize that UVR protective mechanisms inherent in Montipora spp. mitigate this reproductive damage.


Asunto(s)
Antozoos/crecimiento & desarrollo , Cambio Climático , Reproducción/fisiología , Motilidad Espermática/genética , Animales , Antozoos/genética , Arrecifes de Coral , Células Germinativas/crecimiento & desarrollo , Potencial de la Membrana Mitocondrial/genética , Océanos y Mares , Motilidad Espermática/fisiología , Rayos Ultravioleta/efectos adversos
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