Montastraea cavernosa is a reef-building coral of the tropical Atlantic (Nunes et al. 2009). It is abundant in the Caribbean, where it has received considerable attention from coral researchers.
Montastraea cavernosa is an abundant reef builder in the Caribbean, being found throughout the region, from Panama to Florida, east to the islands of the Lesser Antilles, and as far north as Bermuda in the north Atlantic. This species is also widespread in the South Atlantic, being common along the coast of Brazil from Cabedelo, Paraiba to Vitoria, Espırito Santo. Montastraea cavernosa has also been reported from the offshore island of Fernando de Noronha, as well as Parcel Manuel Luiz, an offshore reef located 500 km east of the Amazon outflow. Although this species was previously unknown off the north coast of Brazil, Nunes et al. discovered abundant colonies on the offshore reef of Pedra da Risca do Meio at depths of about 25 m. Montastraea cavernosa is also one of the most common coral species in the islands of Sao Tome, Prıncipe and Annobon in the Gulf of Guinea, West Africa, but it has not been reported along the West African mainland nor in the Cape Verde islands farther north. (Nunes et al. 2009 and references therein)
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Nunes et al. (2009) compared the levels of genetic diversity and connectivity in the coral Montastraea cavernosa among both central and peripheral populations throughout its range in the Atlantic. Genetic data from one mitochondrial and two nuclear loci in 191 individuals show that M. cavernosa is subdivided into three genetically distinct regions in the Atlantic: Caribbean-North Atlantic, Western South Atlantic (Brazil) and Eastern Tropical Atlantic (West Africa). Within each region, populations have similar allele frequencies and levels of genetic diversity. No significant differentiation was found between populations separated by as much as 3000 km, suggesting that this coral species has the ability to disperse over large distances. Gene flow within regions does not, however, translate into connectivity across the entire Atlantic. Instead, substantial differences in allele frequencies across regions suggest that genetic exchange is infrequent between the Caribbean, Brazil, and West Africa. Furthermore, markedly lower levels of genetic diversity are observed in the Brazilian and West African populations. Genetic diversity and connectivity may contribute to the resilience of a coral population to disturbance. Isolated peripheral populations may be more vulnerable to human impacts, disease, or climate change relative to those in the genetically diverse Caribbean-North Atlantic region. Although limited dispersal and connectivity in marine organisms can have negative fitness effects in populations that are small and isolated, reduced genetic exchange may also promote the potential for local adaptation.
Kelmanson and Matz (2003) studied the molecular basis of color diversity in Montastraea cavernosa. Typically, each natural pigment in corals and other anthozoans is essentially determined by a sequence of a single protein, homologous to the green fluorescent protein (GFP) fromthe jellyfish Aequorea victoria. [The discovery of GFP in A. victoria in 1962, and its subsequent development as a powerful tool in molecular biology, were the the basis for the 2008 Nobel Prize in Chemistry.] Kelmanson and Matz studied three colonies of Montastraea cavernosa representing distinct color morphs. Unexpectedly, these specimens were found to express the same collection of GFP-like proteins, produced by at least four, and possibly up to seven, different genetic loci. These genes code for three basic colors—cyan, green, and red—and are expressed differently relative to one another in different morphs.
As Kelmanson and Matz note, two basic alternative mechanisms of generating diversity of coloration are possible in principle: genetic polymorphism and polyphenism. Genetic polymorphism is the circumstance in which differences (such as color) can be traced to differences in the genome (i.e., different morphs have different DNA sequences coding for the trait in question). If the Montastraea cavernosa color variation is the result of a simple genetic polymorphism, then the color should be largely determined at the moment of zygote formation (fertilization of an egg), with little possibility for it to change afterwards, except for the intensity. In contrast, "polyphenism" refers to the ability of a single genotype to produce two or more alternative morphologies within a single population in response to an environmental cue. In the case of Montastraea cavernosa, the observed color variation would be an example of polyphenism if the same set of genes coding for GFP-like proteins are present in two or more color morphs, with the differences in color appearance being due to the changes in relative levels of expression of these genes. (The color diversity could also result from a combination of these two models.) In Montastraea cavernosa, the color differences between colonies can be explained by varying levels of expression (specifically, transcript abundances) of a set of genes coding for GFP-like proteins. The set includes at least four, and probably up to seven, separate genetic loci and encodes proteins emitting at three general wavebands: cyan (wide emission peak at around 495 nm), green (narrow emission peak at 505 to 520 nm), and red (emission at 580 nm). Kelmanson and Matz found that two different color morphs of Montastraea cavernosa, green and red, contained and expressed the same functional suite of color genes. No environmental cues are yet known that would confirm this color variation as environmentally-based polyphenism, but the authors suggest that depth could be one factor affecting color expression (Kelmanson and Matz 2003).
In contrast to most coral species in the family Faviidae, colonies of Montastraea cavernosa are generally either all-male or all-female. They are broadcast spawners. In a study on the Caribbean coast of Colombia (October 1990 to October 1991), Acosta and Zea (1997) found that there was a single gametogenic (egg- and sperm-producing) cycle per year in both sexes. The duration of the oogenic cycle was ~11 months, with oogenesis (egg production) in all months except just after spawning (Szmant 1991). Of the colonies with gonads sampled in November 1990, all female eggs were already in Stage I. Development of eggs to Stage II (yolk comprising up to 50% of the cytoplasm) was evident in late December 1990 to early January 1991, and development of Stage III eggs began in March 1991. A marked increase in the mean gonad index did not occur until after July 1991. In contrast to the female cycle, the spermatogenic cycle lasted only 2 to 4 months. Male gonads, were first evident in October and November 1990, disappeared until the full moon of June, when testes with most spermatic cysts in Stage I were observed. Stages II and III cysts were evident from the beginning of the cycle, but the latter constituted a large percent of the sex products only after August 1991. The mean gonad index increased from June through October. By and after the full moon of October 1990 and 1991, most cysts of male colonies were in Stage III. Spawning did not occur synchronously within the population, since maturing, fully mature and spawned colonies were found simultaneously on several sampling dates. (Acosta and Zea 1997 and references therein). Zooxanthellae are not present in the eggs and must be acquired from the water column de novo during the planktonic larval phase or after settlement (Szmant 1991). Broadcast spawning is now recognized as typical for reef-building corals, but for years brooding with multiple planulation cycles (production within, and release from, coral polyps) of planula larvae per year was thought to be the norm for reef corals (Szmamt 1991).
In a study of seven "massive" Caribbean corals, Soong (1993) identified major differences in reproductive behavior between species with large maximum colony size (>100 cm2 in surface area), including Montastraea cavernosa, and species with small maximum colony size. The four large species studied broadcast gametes during a short spawning season; the two smaller-sized and one medium-sized species brooded larvae during an extended season (year-round in Panama).
Prior to the early 1980s, for over 200 years, all corals were believed to be viviparous (brooding). It is now known that most reef-building corals release, or "broadcast", eggs and sperm into the water column during periodic and often synchronous spawning events. For decades researchers have speculated about and worked to identify environmental entrainment factors that might influence sexual reproduction and the eventual release of gametes. This synchronization is generally believed to operate on at least three interrelated temporal levels: (1) the time of the year; (2) the lunar cycle; and (3) the time of night. It is clear that nighttime is required for gamete release, but a consistent global relationship between lunar phase and the timing of spawning is less clear, given that most corals on the Great Barrier Reef in Australia spawn at neap tides, while the same species in southern Japan spawn at spring tides. It has seemed reasonable to assume that the time of the year for gamete release is linked to optimal sea surface temperature (SST). van Woesik et al. (2006), however, have argued that solar insolation (energy from the sun), is a better predictor of gamete production for many corals.They tested this hypothesis using data for 12 species of corals distributed throughout the Caribbean (tropical west Atlantic), including Montastraea cavernosa. Regarding temperature, they found that the cumulative dose of SST measured through time and the rate of change in temperature correlated poorly with the timing of coral spawning, although the average temperature during the month of spawning was significantly correlated with spawning. For solar insolation, they found that the rate of change and the cumulative response of solar insolation cycles was a better predictor of gamete release, although solar insolation intensity at the time of spawning was not. All of the coral species they examined showed highly significant positive relationships between spawning date and the cumulative dose of solar insolation, and 11 of 12 species, including Montastraea cavernosa, showed a significant response to the rate of change in solar insolation. Solar insolation and temperature are obviously related phenomena since solar irradiance ultimately drives SST, but because of the high specific heat capacity of water, maximum SST generally lags 1 to 2 months (or more) behind maximum solar insolation. Time delays in SST fluctuations are latitudinally predictable but vary with cloud-cover and windstrength. van Woesik et al. concluded that solar insolation influences the reproductive schedules of Caribbean corals, but water temperatures must be optimal (28–30 C) to allow maturation and gamete release. (van Woesik et al. 2006 and referencess therein)
Vize (2006) asserts that for shallow water corals, annual water temperature cycles set the month, lunar periodicity the day, and sunset time the hour of spawning. This tight temporal regulation is critical for achieving high fertilization rates in a pelagic environment. Given the differences in light and temperature that occur with depth and the importance of these parameters in regulating spawn timing, it it had been unclear whether corals in deeper water can respond to the same environmental cues that regulate spawning behaviour in shallower coral. Vize used a remotely operated vehicle to monitor coral spawning (including that of Montastraea cavernosa) activity at the Flower Garden Banks (northwest Gulf of Mexico) at depths from 33 to 45 meters. All recorded spawning events were within the same temporal windows as shallower conspecifics. These data indicate that deep corals at this location either sense the same environmental parameters, despite local attenuation, or communicate with shallower colonies that can sense such spawning cues.
Colonies of the Caribbean coral Montastraea cavernosa that harbor endosymbiotic cyanobacteria can fix nitrogen, whereas conspecifics without these symbionts cannot. Zooxanthellae (the coral's symbiotic photosynthetic dinoflagellate algae partners) appear to be somehow able to use these supplementary sources of nitrogen and increase their growth rates without compromising the integrity of the symbiosis (Lesser et al. 2007). Nitrogen limitation has long been proposed to contribute to the stability of the coral-zooxanthellae symbiosis. How this symbiosis is maintained despite nitrogen supplementation from nitrogen-fixing cyanobacteria is an open question.
Montastraea cavernosa ist eine Steinkoralle (Scleractinia). Wie die meisten Steinkorallen sind es Kolonien, die aus vielen Tausenden Einzelpolypen bestehen. Ein einzelner Polyp kann einen Durchmesser von zwölf Millimeter erreichen, Montastraea cavernosa gehört zu den Großpolypigen Steinkorallen. Die Gesamtkolonie wächst kuppelförmig und kann zwei Meter hoch werden.
Montastraea cavernosa lebt im tropischen westlichen Atlantik, bei den Bahamas, in der Karibik und entlang der Küste Brasiliens bis Rio de Janeiro. In der Karibik ist sie eine der wichtigsten riffbauenden Korallen. Außerdem gibt es noch eine Population im östlichen Atlantik, bei den Inseln im Golf von Guinea. Die Koralle wächst in Tiefen von einem bis 90 Metern. Im Süden des Verbreitungsgebietes erreichen die Kolonien nur noch Durchmesser von einem Meter und bilden krustenartige Überzüge auf Felsen.
Montastraea cavernosa ist eine Steinkoralle (Scleractinia). Wie die meisten Steinkorallen sind es Kolonien, die aus vielen Tausenden Einzelpolypen bestehen. Ein einzelner Polyp kann einen Durchmesser von zwölf Millimeter erreichen, Montastraea cavernosa gehört zu den Großpolypigen Steinkorallen. Die Gesamtkolonie wächst kuppelförmig und kann zwei Meter hoch werden.
Montastraea is a genus of colonial stony coral found in the Caribbean seas. It is the only genus in the monotypic family Montastraeidae and contains a single species, Montastraea cavernosa, known as great star coral. It forms into massive boulders and sometimes develops into plates. Its polyps are the size of a human thumb and fully extend at night.[2]
Great star coral colonies form massive boulders and domes over 5 feet (1.5 m) in diameter in waters of shallow and moderate depths. In deeper waters, this coral has been observed growing as a plate formation. It is found throughout most reef environments, and is the predominant coral at depths of 40–100 feet (12.2-30.5 m).
This coral occasionally has a fluorescent red or orange color during daytime; it has recently been suggested that this hue is due to phycoerythrin, a cyanobacterial protein. It appears that, in addition to symbiotic zooxanthella, this coral harbors endocellular symbiotic cyanobacteria, possibly to help it fix nitrogen. However more recently, Oswold et al. (2007) showed an absence of functional phycoerythrin in M. cavernosa.[3]
The species is gonochoric (colonies can be either male or female) and spawns one week after the full moon in late August. Skeletons show sex-related differences, with females having a less dense skeleton compared to males, which is presumably due to reallocating energy to egg production.[4]
The distinction of bleaching in reefs of M. cavernosa from merely white-coloured corals was shown to be difficult using standard reflectance techniques. A survey in the Bay of All Saints concluded that this may lead to nearly two-fold overestimation of bleaching.[5]
Montastraea is a genus of colonial stony coral found in the Caribbean seas. It is the only genus in the monotypic family Montastraeidae and contains a single species, Montastraea cavernosa, known as great star coral. It forms into massive boulders and sometimes develops into plates. Its polyps are the size of a human thumb and fully extend at night.
Montastraea cavernosa es una especie de coral que pertenece al grupo de los corales duros, orden Scleractinia, y a la familia Montastraeidae.[2]
Su esqueleto es macizo y está compuesto de carbonato cálcico. Tras la muerte del coral, su esqueleto contribuye a la generación de nuevos arrecifes en la naturaleza.
Las colonias son generalmente pequeñas, midiendo alrededor de 50 cm a lo largo. En algunos casos tienen forma cónica, y en general tienen mayor tamaño a lo largo que a lo ancho, también se desarrollan en forma de loma y aplanadas.[3] En general las colonias de esta especie no llegan a crecer tanto como las otras especies de Montastraea.
Los cálices son mucho más grandes (2 o 3 veces más) que en otras especies de Montastraea, éstos son de forma cónica, tienen un diámetro entre 0,5 a 0,75 cm o más y están claramente separados y divididos por brotes extra-tentaculares.[4] Los pólipos son abultados y de apariencia carnosa, mostrando también por el día sus tentáculos.
También posee tentáculos "barredores" que presentan unas células urticantes denominadas nematocistos, empleadas en la caza de presas de plancton. Esta especie los mantiene desplegados todo el tiempo, siendo inusual, ya que la mayoría de corales que los poseen tan sólo los despliegan para cazar o atacar, normalmente sólo de noche.
El color puede ser marrón, rojizo, naranja, verde o grisáceo, normalmente con el disco oral contrastando con un color diferente.
Viven en casi todas las diferentes zonas de los arrecifes localizados en las zonas tropicales (a una latitud situada entre 30ºN y 20ºS) en zonas cercanas a las costas. Abundan en aguas túrbias y de poca calidad.
Habita normalmente entre 10 y 30 m de profundidad, aunque se encuentra desde 0,5 hasta los 113 m.[1]
Se distribuyen en aguas tropicales del océano Atlántico, junto a las costas occidentales de África y a las orientales de América.
Es especie nativa de Anguila; Antigua y Barbuda; Bahamas; Barbados; Belice; Benín; Bermuda; Bonaire, Sint Eustatius y Saba (Saba, Sint Eustatius); Brasil; Camerún; Cabo Verde; islas Caimán; Colombia; Costa Rica; Costa de Marfil; Cuba; Curasao; Dominica; República Dominicana; Guinea Ecuatorial; Estados Unidos; Gabón; Gambia; Ghana; Granada; Guadalupe; Guinea; Guinea-Bissau; Haití; Honduras; Jamaica; Liberia; Mauritania; México; Montserrat; Nicaragua; Nigeria; Panamá; Saint Barthélemy; San Cristóbal y Nieves; Santa Lucía; Saint Martin (Parte francesa); Saint Vicente y las Granadinas; Santo Tomé y Príncipe; Senegal; Sierra Leona; Sint Maarten (Parte holandesa); Togo; Trinidad y Tobago; Turks y Caicos; Venezuela e islas Vírgenes Británicas.[1]
Contienen algas simbióticas mutualistas (ambos organismos se benefician de la relación), llamadas zooxantelas. Las algas realizan la fotosíntesis produciendo oxígeno y azúcares, que son aprovechados por los pólipos, y se alimentan de los catabolitos del coral (especialmente fósforo y nitrógeno).[5] Esto les proporciona entre el 70 y el 95% de sus necesidades alimenticias. El resto lo obtienen atrapando plancton y materia orgánica disuelta en el agua.
Se reproducen asexualmente mediante gemación, y, sexualmente, lanzando al exterior sus células sexuales. Esta especie conforma colonias macho o hembra, siendo las condiciones ambientales las que determinan el sexo. En este tipo de reproducción, los corales liberan óvulos y espermatozoides al agua, entre julio y octubre, siendo por tanto la fecundación externa. Los huevos, una vez en el exterior, permanecen a la deriva arrastrados por las corrientes varios días, más tarde se forma una larva plánula[6] que cae al fondo, se adhiere a él y comienza su vida sésil, secretando carbonato cálcico para conformar un esqueleto individual, o coralito. Posteriormente se reproduce por gemación, conformando así la colonia coralina.
Su mantenimiento en cautividad es relativamente fácil, comparado con el resto de corales duros, al provenir de aguas turbias. No requiere iluminación intensa.[7]
La iluminación deberá ser moderada y la corriente de suave a moderada, ya que una corriente fuerte puede evitar la expansión de los pólipos. Conviene vigilar el nivel de calcio con frecuencia debido a su alto consumo. Se recomienda un acuario maduro y estable, los cambios de temperatura o acidez pueden provocarle estrés y llevarle al blanqueamiento.
Al tener tentáculos "barredores" para la caza, se debe dejar espacio a su alrededor, ya que, de lo contrario, dañará a los corales vecinos.
Montastraea cavernosa, en el Santuario Nacional Marino de Flower Gardens Banks, EE.UU.
Thalassoma bifasciatum sobre colonias de M. cavernosa en Bonaire
Elacatinus oceanops en M. cavernosa con tentáculos retraidos.
Colonias de M. cavernosa en el Gólfo de México.
Un M. cavernosa con los tentáculos de los pólipos totalmente extendidos.
Montastraea cavernosa es una especie de coral que pertenece al grupo de los corales duros, orden Scleractinia, y a la familia Montastraeidae.
Su esqueleto es macizo y está compuesto de carbonato cálcico. Tras la muerte del coral, su esqueleto contribuye a la generación de nuevos arrecifes en la naturaleza.
Montastraea cavernosa est une espèce de coraux appartenant à la famille des Montastraeidae[2].
Montastraea cavernosa est une espèce de coraux appartenant à la famille des Montastraeidae.
Montastraea cavernosa (Linnaeus, 1766) è una madrepora diffusa nelle barriere coralline dell'oceano Atlantico. È l'unica specie del genere Montastraea e della famiglia Montastraeidae.[2]
È una specie coloniale che forma aggregazioni che possono raggiungere i 50 cm di diametro, di forma da conica a colonnare, ma talora anche incrostante.[3]
I coralliti hanno calici di 5-7 mm di diametro, e sono di forma conica, nettamente distinti l'uno dall'altro. I polipi possono essere parzialmente estroflessi durante le ore del giorno.
Questa specie è diffusa nella fascia tropicale di entrambe le sponde dell'oceano Atlantico. Popola le barriere coralline dei Caraibi, del golfo del Messico, della Florida, delle Bahamas, delle Bermuda e del Brasile. È presente inoltre negli arcipelaghi brasiliani di Fernando de Noronha e Atol das Rocas, e negli arcipelaghi africani di Capo Verde e São Tomé e Príncipe.[1]
Montastraea cavernosa (Linnaeus, 1766) è una madrepora diffusa nelle barriere coralline dell'oceano Atlantico. È l'unica specie del genere Montastraea e della famiglia Montastraeidae.
Montastraea cavernosa is een rifkoralensoort uit de familie van de Montastraeidae.[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1767 door Linnaeus.
Bronnen, noten en/of referenties
A Montastraea cavernosa é um organismo colonial, pertencente à ordem Scleractinia do filo Cnidaria (corais, anémonas e medusas). A sua área de distribuição situa-se nos mares que banham as Caraíbas e Golfo do México. Normalmente adquire a forma e aspecto de grandes e maciças rochas, desenvolvendo-se, por vezes, com a forma de pratos. Os pólipos têm o comprimento de um polegar humano, encontrando-se completamente abertos durante a noite.
Esta espécie de coral por vezes apresenta uma coloração vermelha ou laranja fluorescente durante o dia; recentemente descobriu-se que esta tonalidade deve-se à presença de ficoeritrina, uma proteína presente em cianobactérias. Ao que parece, este coral, além das zooxantelas simbióticas, abrigue cianobactérias endocelulares, provavelmente como forma de faciltar a fixação de azoto
A Montastraea cavernosa é um organismo colonial, pertencente à ordem Scleractinia do filo Cnidaria (corais, anémonas e medusas). A sua área de distribuição situa-se nos mares que banham as Caraíbas e Golfo do México. Normalmente adquire a forma e aspecto de grandes e maciças rochas, desenvolvendo-se, por vezes, com a forma de pratos. Os pólipos têm o comprimento de um polegar humano, encontrando-se completamente abertos durante a noite.
Esta espécie de coral por vezes apresenta uma coloração vermelha ou laranja fluorescente durante o dia; recentemente descobriu-se que esta tonalidade deve-se à presença de ficoeritrina, uma proteína presente em cianobactérias. Ao que parece, este coral, além das zooxantelas simbióticas, abrigue cianobactérias endocelulares, provavelmente como forma de faciltar a fixação de azoto
Montastraea cavernosa là một loài san hô trong họ Faviidae.[2][3] Chúng thường được tìm thấy trong vùng biển Caribbean. Nó hình thành những tảng lớn và đôi khi phát triển thành tấm. Polyp của nó có kích thước của một ngón tay cái của con người và hoàn toàn mở rộng vào ban đêm. Chúng tạo thành quần thể ở các tảng hình mái vòm lớn có đường kính hơn 1,5 mét ở vùng biển độ sâu nông và trung bình. Trong vùng nước sâu hơn, san hô này được quan sát thấy phát triển thành hình tấm. Nó được tìm thấy trong suốt hầu hết các môi trường rạn san hô, và chủ yếu là san hô ở độ sâu 12,2-30,5 m.
Loài san hô này đôi khi có màu đỏ huỳnh quang hoặc màu da cam vào ban ngày, và gần đây người ta cho rằng màu sắc này là do phycoerythrin, một protein từ cyanobacteria.
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Bài viết liên quan đến Lớp San hô này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Montastraea cavernosa là một loài san hô trong họ Faviidae. Chúng thường được tìm thấy trong vùng biển Caribbean. Nó hình thành những tảng lớn và đôi khi phát triển thành tấm. Polyp của nó có kích thước của một ngón tay cái của con người và hoàn toàn mở rộng vào ban đêm. Chúng tạo thành quần thể ở các tảng hình mái vòm lớn có đường kính hơn 1,5 mét ở vùng biển độ sâu nông và trung bình. Trong vùng nước sâu hơn, san hô này được quan sát thấy phát triển thành hình tấm. Nó được tìm thấy trong suốt hầu hết các môi trường rạn san hô, và chủ yếu là san hô ở độ sâu 12,2-30,5 m.
Loài san hô này đôi khi có màu đỏ huỳnh quang hoặc màu da cam vào ban ngày, và gần đây người ta cho rằng màu sắc này là do phycoerythrin, một protein từ cyanobacteria.
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