scholarly journals Morphological stasis masks ecologically divergent coral species on tropical reefs

2020 ◽  
Author(s):  
P Bongaerts ◽  
IR Cooke ◽  
H Ying ◽  
D Wels ◽  
S Haan den ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Coral Species ◽  
Common Garden ◽  
Genomic Signatures ◽  
Morphological Stasis ◽  
Sequencing Studies ◽  
Demographic Modelling ◽  
Whole Genome Resequencing ◽  
Taxonomic Framework

ABSTRACTCoral reefs are the epitome of species diversity, yet the number of described scleractinian coral species, the framework-builders of coral reefs, remains moderate by comparison. DNA sequencing studies are rapidly challenging this notion by exposing a wealth of undescribed diversity, but the evolutionary and ecological significance of this diversity remains largely unclear. Here, we present an annotated genome for one of the most ubiquitous corals in the Indo-Pacific (Pachyseris speciosa), and uncover through a comprehensive genomic and phenotypic assessment that it comprises morphologically indistinguishable, but ecologically divergent cryptic lineages. Demographic modelling based on whole-genome resequencing disproved that morphological crypsis was due to recent divergence, and instead indicated ancient morphological stasis. Although the lineages occur sympatrically across shallow and mesophotic habitats, extensive genotyping using a rapid diagnostic assay revealed differentiation of their ecological distributions. Leveraging “common garden” conditions facilitated by the overlapping distributions, we assessed physiological and quantitative skeletal traits and demonstrated concurrent phenotypic differentiation. Lastly, spawning observations of genotyped colonies highlighted the potential role of temporal reproductive isolation in the limited admixture, with consistent genomic signatures in genes related to morphogenesis and reproduction. Overall, our findings demonstrate how ecologically and phenotypically divergent coral species can evolve despite morphological stasis, and provide new leads into the potential mechanisms facilitating such divergence in sympatry. More broadly, they indicate that our current taxonomic framework for reef-building corals may be scratching the surface of the ecologically relevant diversity on coral reefs, consequently limiting our ability to protect or restore this diversity effectively.

scholarly journals Distribution and Diversity of Archaeal Ammonia Monooxygenase Genes Associated with Corals

2007 ◽  
Vol 73 (17) ◽  
pp. 5642-5647 ◽  
Author(s):  
J.Michael Beman ◽  
Kathryn J. Roberts ◽  
Linda Wegley ◽  
Forest Rohwer ◽  
Christopher A. Francis
Keyword(s):  
Coral Reefs ◽  
Microbial Communities ◽  
Coral Species ◽  
Estuarine Sediments ◽  
Ammonia Monooxygenase ◽  
Oceanic Water ◽  
Ecological Role ◽  
Bocas Del Toro ◽  
Water Columns

ABSTRACT Corals are known to harbor diverse microbial communities of Bacteria and Archaea, yet the ecological role of these microorganisms remains largely unknown. Here we report putative ammonia monooxygenase subunit A (amoA) genes of archaeal origin associated with corals. Multiple DNA samples drawn from nine coral species and four different reef locations were PCR screened for archaeal and bacterial amoA genes, and archaeal amoA gene sequences were obtained from five different species of coral collected in Bocas del Toro, Panama. The 210 coral-associated archaeal amoA sequences recovered in this study were broadly distributed phylogenetically, with most only distantly related to previously reported sequences from coastal/estuarine sediments and oceanic water columns. In contrast, the bacterial amoA gene could not be amplified from any of these samples. These results offer further evidence for the widespread presence of the archaeal amoA gene in marine ecosystems, including coral reefs.

scholarly journals The role of zooxanthellae in the thermal tolerance of corals: a ‘nugget of hope’ for coral reefs in an era of climate change

2006 ◽  
Vol 273 (1599) ◽  
pp. 2305-2312 ◽  
Author(s):  
Ray Berkelmans ◽  
Madeleine J.H van Oppen
Keyword(s):  
Climate Change ◽  
Coral Reefs ◽  
Thermal Tolerance ◽  
Coral Species ◽  
Experimental Manipulation ◽  
Direct Result ◽  
Symbiont Type ◽  
Thermal Acclimatization ◽  
Highly Sensitive

The ability of coral reefs to survive the projected increases in temperature due to global warming will depend largely on the ability of corals to adapt or acclimatize to increased temperature extremes over the next few decades. Many coral species are highly sensitive to temperature stress and the number of stress (bleaching) episodes has increased in recent decades. We investigated the acclimatization potential of Acropora millepora , a common and widespread Indo-Pacific hard coral species, through transplantation and experimental manipulation. We show that adult corals, at least in some circumstances, are capable of acquiring increased thermal tolerance and that the increased tolerance is a direct result of a change in the symbiont type dominating their tissues from Symbiodinium type C to D. Our data suggest that the change in symbiont type in our experiment was due to a shuffling of existing types already present in coral tissues, not through exogenous uptake from the environment. The level of increased tolerance gained by the corals changing their dominant symbiont type to D (the most thermally resistant type known) is around 1–1.5 °C. This is the first study to show that thermal acclimatization is causally related to symbiont type and provides new insight into the ecological advantage of corals harbouring mixed algal populations. While this increase is of huge ecological significance for many coral species, in the absence of other mechanisms of thermal acclimatization/adaptation, it may not be sufficient to survive climate change under predicted sea surface temperature scenarios over the next 100 years. However, it may be enough to ‘buy time’ while greenhouse reduction measures are put in place.

The role of waterlogging and sand accretion in modulating the morphology of the dune slack plant Scirpus americanus

1990 ◽  
Vol 68 (8) ◽  
pp. 1780-1787 ◽  
Author(s):  
Denise M. Seliskar
Keyword(s):  
Sand Dune ◽  
Plant Morphology ◽  
Common Garden ◽  
Stem Growth ◽  
Reciprocal Transplant ◽  
Dune Slack ◽  
Coastal Sand Dune ◽  
Scirpus Americanus ◽  
Common Garden Experiments

Scirpus americanus Pers., a major dune slack plant in coastal sand dune ecosystems, differs in height along transects ranging between the lowest and highest elevational areas of slacks located along the coast of Delaware, U.S.A. Using reciprocal transplant and common garden experiments, results suggest that environmental factors rather than hereditary traits are more important in accounting for the differences in plant morphology expressed in the field. Dune slack plants are exposed to stresses of waterlogging and sand accretion in their natural environment. In controlled greenhouse experiments waterlogging was shown to inhibit stem growth and cause an increase in aerenchymatous tissue, whereas periodic sand deposition caused an increase in the plant height of Scirpus.

scholarly journals Coralivoría del gasterópodo Jenneria pustulata (Ovulidae: Pediculariinae) en dos arrecifes coralinos del PNN isla Gorgona

2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Mauro Giovanni Zucconi ◽  
Levy D. Obonaga ◽  
Edgardo Londoño-Cruz
Keyword(s):  
Coral Reefs ◽  
Coral Species ◽  
Size Structure ◽  
Coral Tissue ◽  
Laboratory Conditions ◽  
Set Up ◽  
Biological Dynamics ◽  
Colombian Pacific

Coral reefs are very important and highly biodiverse ecosystems that are exposed to various stressors, including biological ones, such as parasitism and corallivory – the direct consumption of coral tissue by a predator. Knowledge on the effects of corallivory on the coral reefs in the Colombian Pacific is poor. Therefore a study was set up to quantify the abundance of and the corallivory rate by the snail Jenneria pustulata in La Azufrada and Playa Blanca coral reefs (Gorgona Island, Colombia). Snails were manually sampled from the underside of Pocillopora sp. colonies and measured in situ to determine their size structure for each reef. To measure possible damage caused by corallivory, several snails were kept under controlled laboratory conditions for 24 h. Snail sizes and corallivory varied significantly between reefs (P=0.0001; P«0.001). Snails from Playa Blanca were larger than snails from La Azufrada, while corallivory was higher in La Azufrada than in Playa Blanca. Although corallivory rates by J. pustulata are smaller than rates reported for other predators in different coral species, it is recommended to continue this kind of investigations in order to increase the knowledge on biological dynamics of this species and to understand how they affect the reefs at Gorgona Island.

scholarly journals STATUS TERUMBU KARANG DI PERAIRAN PESISIR NEGERI HUKURILA

2021 ◽  
Vol 17 (1) ◽  
pp. 35-45
Author(s):  
Dicky Sahetapy ◽  
Laura Siahainenia ◽  
Debby A J Selanno ◽  
Johannes M S Tetelepta ◽  
Novianty C Tuhumury
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coastal Waters ◽  
Coral Species ◽  
Similarity Index ◽  
Ecological Index ◽  
Stony Coral ◽  
The Status ◽  
Coral Communities ◽  
Line Intercept

Coral reef is one of the important coastal ecosystems that have high biodiversity. This study aims to analyze the composition of the taxa and the distribution of coral species, the ecological index of coral communities and the status of coral reefs. The research was conducted from April-May 2019 in the coastal waters of Hukurila Village, South Leitimur District, Ambon City. Collecting coral data by using the Line Intercept Transect (LIT) method. Determination of coral reef condition based on percent data (value) of coral reef cover. During the study, 116 species of stony coral from 49 genera and 16 families were found, which 50 species of them are protected and 23 species of ornamental coral. The similarity index of stony coral species between coral reef locations ranges from 0.52-0.76 or there is the similarity of stony coral species between locations coral reef in the amount of 52-76%. The coral reefs of Hukurila Village have high diversity of coral species, with a low dominance of coral species in the community, and the compatibility of coral species in the community is classified as stable. Acropora corals contributed a low covering percent value (9.98%), while Non-Acropora corals contributed a relatively high percent of covering value (43.56%). The status of coral reefs between locations in the coastal waters of Hukurila Village is in the criteria of good (healthy).   ABSTRAK Terumbu karang merupakan salah satu ekosistem pesisir penting yang emiliki kenanekaragaman hayati tinggi. Penelitian ini bertujuan untuk menganalisis komposisi taksa dan sebaran spesies karang, indeks ekologi kominitas karang dan status terumbu karang. Penelitian dilakukan dari April-Mei 2019 di perairan pesisir Negeri Hukurila Kecamatan Leitimur Selatan Kota Ambon. Pengumpulan data karang menggunakan metode Line Intercept Transect (LIT). Penentuan kondisi terumbu karang berdasarkan data (nilai) persen penutupan karang batu. Selama penelitian ditemukan 116 spesies karang batu dari 49 genera dan 16 famili, dimana 50 spesies diantaranya dilindungi dan 23 spesies karang hias. Indeks similaritas spesies karang batu antar stasiun terumbu karang berkisar antara 0,52-0,76 atau terdapat kesamaan spesies karang batu antar lokasi terumbu karang sebesar 52-76%. Terumbu karang Negeri Hukurila memiliki diversitas spesies karang tinggi, dengan dominansi spesies karang rendah dalam komunitas, dan keserasian spesies karang dalam komunitas tergolong stabil. Karang Acropora memberi kontribusi nilai persen penutupan rendah (9,98%), sementara karang Non-Acropora memberi kontribusi nilai persen penutupan karang batu relatif tinggi (43,56%). Status terumbu karang antar stasiun terumbu perairan pesisir Negeri Hukurila berada dalam kriteria baik (sehat).   Kata kunci: terumbu, karang batu, keragaman spesies, kesamaan, persen penutupan

scholarly journals River Streamflow, Remotely Sensed Water Quality, and Benthic Composition of Previously Undescribed Nearshore Coral Reefs in Northern Puerto Rico

2021 ◽  
Vol 8 ◽  
Author(s):  
Juan L. Torres-Pérez ◽  
Carlos E. Ramos-Scharrón ◽  
William J. Hernández ◽  
Roy A. Armstrong ◽  
Maritza Barreto-Orta ◽  
...  
Keyword(s):  
Water Quality ◽  
Puerto Rico ◽  
Coral Reefs ◽  
Coral Species ◽  
Coral Cover ◽  
Remotely Sensed ◽  
North Coast ◽  
Acropora Palmata ◽  
Chl A ◽  
Benthic Composition

Land-based sediment stress represents a threat to many coral reefs in Puerto Rico primarily as a result of unrestricted land cover/land use changes and poor best management practices. The effects of such stresses have been documented along most coasts around the island. However, little attention has been paid to reefs located on the north coast, and very little is known about their composition and current state. Here, we present a study characterizing riverine inputs, water quality conditions, and benthic composition of two previously undescribed coral reefs (Tómbolo and Machuca reefs) located just eastward of the Río Grande de Manatí outlet in north-central Puerto Rico. This study utilizes a time series of remotely sensed ocean color products [diffuse vertical attenuation coefficient at 490 nm (Kd490) and chlorophyll-a concentration (Chl-a) estimated with data from the Visible Infrared Imaging Radiometer Suite (VIIRS)] to characterize water quality in this coastal region. In general, the months with relatively high mean daily river streamflow also coincide with months having the highest proportion of eastward wave direction, which can promote the eastward influence of river waters toward the two coral reefs sites. Kd490 and Chl-a showed a higher riverine influence closer to the watershed outlet. Kd490 and Chl-a monthly peaks also coincide with river streamflow highs, particularly at those pixels closer to shore. Tómbolo Reef, located farther eastward of the river outlet, shows a well-developed primary reef framework mainly composed of threatened reef-building species (Acropora palmata, Pseudodiploria) and high coral cover (19–51%). The benthos of Machuca Reef, located closer to the river outlet, is dominated by macroalgae with a significantly lower coral cover (0.2–2.7%) mainly composed of “weedy” coral species (Porites astreoides and Siderastrea radians). Cover of major benthic components correlates with distance from the river outlet, and with gradients in Kd490 and Chl-a, with higher coral cover and lower macroalgal cover farther from the river outlet. Coral cover at Tómbolo Reef is higher than what has been reported for similar sites around Puerto Rico and other Caribbean islands showing its ecological importance, and as up until now, an unrecognized potential refuge of reef-building threatened coral species.

scholarly journals The role of top-predator in the preservation of coral reefs ecosystem

2017 ◽  
Vol 1 (1) ◽  
pp. 54
Author(s):  
Rina Ratianingsih ◽  
Nurul Ismawati ◽  
Juni Wijayanti Puspita ◽  
Agus Indra Jaya
Keyword(s):  
Coral Reefs ◽  
Top Predator

The coral reef-dwelling Peneroplis spp. shows calcification resilience to ocean acidification conditions - results from culture experiments

2021 ◽  
Author(s):  
Laurie Charrieau ◽  
Katsunori Kimoto ◽  
Delphine Dissard ◽  
Beatrice Below ◽  
Kazuhiko Fujita ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Ocean Acidification ◽  
Sea Water ◽  
General Structure ◽  
Ion Concentration ◽  
Large Benthic Foraminifera ◽  
Carbonate Ion ◽  
Short Period

<p>Ocean acidification is a consequence of current anthropogenic climate changes. The concomitant decrease in pH and carbonate ion concentration in sea water may have severe impacts on calcifying organisms. Coral reefs are among the first ecosystems recognized vulnerable to ocean acidification. Within coral reefs, large benthic foraminifera (LBF) are major calcium carbonate producers.</p><p>The aim of this study was to evaluate the effects of varying pH on survival and calcification of the symbiont-bearing LBF species <em>Peneroplis</em> spp. We performed culture experiments to study their resistance to ocean acidification conditions, as well as their resilience once placed back under open ocean pH (7.9).</p><p>After three days, small signs of test decalcification were observed on specimens kept at pH 7.4, and severe test decalcification was observed on specimens kept at pH 6.9, with the inner organic lining clearly appearing. After 32 days under pH 7.4, similar strongly decalcified specimens were observed. All the specimens were alive at the end of the experiment. This result demonstrates the resistance of <em>Peneroplis </em>spp. to an acidified pH, at least on a short period of time.</p><p>After being partially decalcified, some of the living specimens were placed back at pH 7.9. After one month, the majority of the specimens showed recalcification features, mostly by addition of new chambers. The trace elements concentrations of the newly formed chambers were analysed by LA-ICPMS. Interestingly, more chambers were added when food was given, which highlights the crucial role of energy source in the recalcification process. Moreover, the newly formed chambers were most of the time abnormal, and the general structure of the tests was altered, with potential impacts on reproduction and in situ survival. In conclusion, if symbiont-bearing LBF show some resistance and resilience to lowered pH conditions, they will remain strongly affected by ocean acidification.</p>

scholarly journals Nocturnal Predation of Christmas Tree Worms by a Batwing Coral Crab at Bonaire (Southern Caribbean)

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 455
Author(s):  
Ellen Muller ◽  
Werner de Gier ◽  
Harry A. ten Hove ◽  
Godfried W. N. M. van Moorsel ◽  
Bert W. Hoeksema
Keyword(s):  
Coral Reefs ◽  
Coral Species ◽  
Christmas Tree ◽  
Stony Coral ◽  
Southern Caribbean

Christmas tree worms (Serpulidae: Spirobranchus) occur in shallow parts of coral reefs, where they live as associates of a large number of stony coral species [...]

scholarly journals The Role of Merlin/NF2 Loss in Meningioma Biology

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1633 ◽  
Author(s):  
Sungho Lee ◽  
Patrick J. Karas ◽  
Caroline C. Hadley ◽  
James C. Bayley V ◽  
A. Basit Khan ◽  
...  
Keyword(s):  
Early Recognition ◽  
Neurofibromatosis Type ◽  
Genetic Alterations ◽  
In Vivo Models ◽  
Inhibition Of Proliferation ◽  
Nf2 Gene ◽  
Sequencing Studies

Mutations in the neurofibromin 2 (NF2) gene were among the first genetic alterations implicated in meningioma tumorigenesis, based on analysis of neurofibromatosis type 2 (NF2) patients who not only develop vestibular schwannomas but later have a high incidence of meningiomas. The NF2 gene product, merlin, is a tumor suppressor that is thought to link the actin cytoskeleton with plasma membrane proteins and mediate contact-dependent inhibition of proliferation. However, the early recognition of the crucial role of NF2 mutations in the pathogenesis of the majority of meningiomas has not yet translated into useful clinical insights, due to the complexity of merlin’s many interacting partners and signaling pathways. Next-generation sequencing studies and increasingly sophisticated NF2-deletion-based in vitro and in vivo models have helped elucidate the consequences of merlin loss in meningioma pathogenesis. In this review, we seek to summarize recent findings and provide future directions toward potential therapeutics for this tumor.

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