The Giant Barrel Sponge (Xestospongia muta) dominates Caribbean coral reef communities, where it is an important spatial competitor, increases habitat complexity, and filters seawater. Average densities of approximately 0.2 individuals per square meter are typical. This sponge has been called the "redwood of the reef" because of its size (often greater than a meter in height and diameter) and its presumed long life. (McMurray et al. 2008)
McMurray et al. (2008) reported on a multi-year study of these sponges in the Florida Keys (U.S.A.). They found that growth rates were variable and decreased with increasing size. The mean specific growth rate was 0.52 per year, but sponges grew as fast or slow as 404% or 2% year. Based on their modeling, the largest sponge in their study was estimated to be 127 years old. Although age extrapolations for very large sponges are subject to more error, McMurray et al. suggest that the largest X. muta present on Caribbean reefs may be in excess of 2,300 years old, which would rank them among the longest-lived animals on earth.
Tissues of X. muta contain Synechococcus cyanobacteria, but it appears that these symbionts are commensals that provide no clear advantage to their sponge host (López-Legentil et al. 2008).
These sponges are vulnerable to a disease syndrome affecting large coral reef sponges known as "sponge orange band’’ (SOB), which generally results in the death of the individuals on which it is observed (McMurray et al. 2008 and references therein).
Synchronous broadcast spawning of male and female Xestospongia muta has been observed (and photographed) in Belize, but the factors triggering and controlling spawning in this species remains unknown (Ritson-Williams 2005).
The giant barrel sponge (Xestospongia muta) is the largest species of sponge found growing on Caribbean coral reefs. It is common at depths greater than 10 metres (33 ft) down to 120 metres (390 ft) and can reach a diameter of 1.8 metres (6 feet). It is typically brownish-red to brownish-gray in color, with a hard or stony texture.[2] The giant barrel sponge has been called the "redwood of the reef"[3] because of its size and estimated lifespan of hundreds to a thousand or more years.[4] It is perhaps the best-studied species of sponge in the sea; a population on Conch Reef, in the Florida Keys, has been monitored and studied since 1997.[5]
The giant barrel sponge is variable in form. It is very large and firm,[2] typically being barrel-shaped, with a cone-shaped cavity at the apex known as the osculum. However, some individuals within the same population may be low and squat or relatively tall and thin. Similarly, the surface can range from smooth to rough, rugged, and irregular, sometimes with buttresses.[2] In shallow water the color is brownish-red to brownish-gray, but at greater depths and in caves and under-hangs, or when the sponge is undergoing cyclic bleaching events, it is pinkish or white.[6]
The giant barrel sponge is common on reefs throughout the Caribbean Sea, the Bahamas, Bermuda and the reefs and hard-bottom areas of Florida and the Gulf of Mexico. In terms of benthic surface coverage, it is the second most abundant sponge on reefs in the Caribbean region.[7] On the reefs off the Florida Keys, it may be as common at two individuals per square metre (yard), and the total biomass of the sponge is greater than any other benthic invertebrate.[5] The sponge grows on any hard surface; the smallest individuals observed are about 1 cm.[5] Two or more closely related species that are visually indistinguishable from X. muta are found on reefs in the Pacific and Indian Oceans (particularly Xestospongia testudinaria).[8]
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The giant barrel sponge is a filter feeder. Water is continually pumped into the sides of the sponge, through the sponge body, and out of the osculum at the top of the sponge. Small pores in the sponge body are connected to channels lined by collar cells, each with a flagellum, and the beating of these flagellae draws water through the channels. Incoming particles, particularly microscopic bacteria and prochlorophytes, are phagocytosed by the collar cells. Sponges like X. muta also absorb dissolved organic compounds directly from the seawater as part of their diet.[9]
The giant barrel sponge is probably dioecious, and spawns its eggs or sperm directly into the water column. Clouds of sperm from males are emitted from the osculum, while females produce flocculent masses of eggs that are slightly negatively buoyant. Spawning can occur at any time of the year, and occurs patchily on the reef, but usually with many individuals participating at the same time. Fertilization occurs in the water column.[10] Resulting sponge larvae disperse with ocean currents, but there is some genetic differentiation among populations from Florida, the Bahamas and Belize.[11]
Growth models for X. muta have been formulated from digital photographs of the same sponges over a period of 4.5 years.[4] Sponge growth rates ranged from over 400% per year to only 2% per year. The largest sponges on Conch Reef, about the size of an oil barrel, were estimated to be about 130 years old. The largest individual for which a photograph was available (now dead) was estimated to be 2300 years old.[4] By using the growth model, the age of an individual X. muta can be estimated from the osculum diameter and the base circumference.[12]
The tissues of the giant barrel sponge contain photosynthetic symbiotic cyanobacteria, Synechococcus Spongiarum,[13] which give the sponge its color. Individuals may undergo periodic bleaching, but this is a cyclic event, and the sponge recovers its normal coloration over time.[6] This cyclical bleaching is likely to be a response by the cyanobacteria rather than by the host sponge, it has no negative effect on the host sponge.[14] Unlike the circumstances for coral bleaching, X. muta does not appear to rely on its photosynthetic symbionts for nutrition, and they are considered commensals.[15] Unrelated to cyclic bleaching is a pathogenic condition of X. muta called "sponge orange band" that can result in the death of the sponge.[16] The cause and transmission of this pathogenic condition remains a mystery.[17]
The giant barrel sponge is an important member of the reef community. Sponges filter large amounts of water, and are a predominant link in benthic-pelagic coupling on reefs and they harbor diverse assemblages of bacteria that can take part in nitrification and carbon fixation.[18] It serves as a habitat for various invertebrates which live on the surface or in the interior[5] and is grazed upon by some parrotfish.[19] It is also host to a diverse community of microbes, some of which are primary producers or involved in nitrification.[20]
The giant barrel sponge (Xestospongia muta) is the largest species of sponge found growing on Caribbean coral reefs. It is common at depths greater than 10 metres (33 ft) down to 120 metres (390 ft) and can reach a diameter of 1.8 metres (6 feet). It is typically brownish-red to brownish-gray in color, with a hard or stony texture. The giant barrel sponge has been called the "redwood of the reef" because of its size and estimated lifespan of hundreds to a thousand or more years. It is perhaps the best-studied species of sponge in the sea; a population on Conch Reef, in the Florida Keys, has been monitored and studied since 1997.
Le Baril de rhum[1] (Xestospongia muta) est une espèce d'éponges de la famille des Petrosiidés.
Xestospongia muta est une des espèces animales pouvant vivre le plus longtemps avec des spécimens dans les Caraïbes estimés avoir plus de 2 300 ans[2].
Il existe une autre démosponge du même genre appelé Xestospongia testudinaria, assez similaire à Xestospongia muta et vivant dans les eaux chaudes du Pacifique-est.
Cette éponge peut mesurer jusqu'à 2 m de haut pour 1 à 2 m de diamètre. Elle est brune ou brun-rouge, l'intérieur est plus clair que l'extérieur. Cette couleur est due à la présence de cyanobactéries symbiotiques du genre Synechococcus dans les tissus de l'éponge[1].
Le Baril de rhum (Xestospongia muta) est une espèce d'éponges de la famille des Petrosiidés.
Xestospongia muta est une des espèces animales pouvant vivre le plus longtemps avec des spécimens dans les Caraïbes estimés avoir plus de 2 300 ans.
Il existe une autre démosponge du même genre appelé Xestospongia testudinaria, assez similaire à Xestospongia muta et vivant dans les eaux chaudes du Pacifique-est.
Xestospongia muta atau yang umum disebut sebagai spons tong raksasa ("giant barrel sponge") adalah spesies spons terbesar yang ditemukan tumbuh di terumbu karang Karibia. Species ini umum ditemukan pada kedalaman 10 meter hingga 120 meter dan dapat mencapai diameter 1,8 meter. Warnanya biasanya kecoklatan-merah hingga kecoklatan-abu-abu, dengan tekstur keras atau berbatu[2]. Spons tong raksasa umum dijuluki "kayu merah di terumbu karang" ("redwood of the reef")[3] karena ukurannya yang besar dan perkiraan umur yang mencapai ratusan hingga seribu tahun atau lebih.[4] X. muta merupakan jenis spons yang paling banyak dipelajari di habitat laut, dimanan populasi di Conch Reef, Florida Keys, telah dipantau dan dipelajari sejak 1997.[5]
X. muta adalah spesies spons yang tergolong dalam kelas Demospongiae. Spesies ini juga merupakan bagian dari kelas Demospongiae, filum Porifera, subregnum Parazoa, dan kingdom Animalia.
Seperti spons pada umumnya, spesies ini memiliki tubuh yang berpori dan permukaan yang keras seperti batu. Selain itu, Xestospongia muta juga dapat menyerap oksigen dari air melalui proses difusi.
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Xestospongia muta atau yang umum disebut sebagai spons tong raksasa ("giant barrel sponge") adalah spesies spons terbesar yang ditemukan tumbuh di terumbu karang Karibia. Species ini umum ditemukan pada kedalaman 10 meter hingga 120 meter dan dapat mencapai diameter 1,8 meter. Warnanya biasanya kecoklatan-merah hingga kecoklatan-abu-abu, dengan tekstur keras atau berbatu. Spons tong raksasa umum dijuluki "kayu merah di terumbu karang" ("redwood of the reef") karena ukurannya yang besar dan perkiraan umur yang mencapai ratusan hingga seribu tahun atau lebih. X. muta merupakan jenis spons yang paling banyak dipelajari di habitat laut, dimanan populasi di Conch Reef, Florida Keys, telah dipantau dan dipelajari sejak 1997.
X. muta adalah spesies spons yang tergolong dalam kelas Demospongiae. Spesies ini juga merupakan bagian dari kelas Demospongiae, filum Porifera, subregnum Parazoa, dan kingdom Animalia.
Seperti spons pada umumnya, spesies ini memiliki tubuh yang berpori dan permukaan yang keras seperti batu. Selain itu, Xestospongia muta juga dapat menyerap oksigen dari air melalui proses difusi.
Artikel batopik porifera ko baru babantuak rancangan. Sanak dapek mambantu Wikipedia mangambangannyo.
Xestospongia muta is een sponssoort in de taxonomische indeling van de gewone sponzen (Demospongiae). Het lichaam van de spons bestaat uit kiezelnaalden en sponginevezels, en is in staat om veel water op te nemen.
De spons behoort tot het geslacht Xestospongia en behoort tot de familie Petrosiidae. De wetenschappelijke naam van de soort werd voor het eerst geldig gepubliceerd in 1870 door Schmidt.
Bronnen, noten en/of referenties
A Xestospongia muta (em inglês: Giant barrel sponge) é uma megaesponja emblemática associada aos corais tropicais. Apresenta uma função ecológica e comercial (sector do turismos) equivalente aos dos corais, sofrendo de igual modo do fenômeno de lixiviação dos mesmos.
A Xestospongia muta tem uma estrutura em forma cilíndrica possuindo um ósculo principal, uma superfície lisa ou com várias irregularidades em forma de dedo, piramidais ou lameladas. O topo é constituído por uma por uma fina parede, com o interior com um padrão. A sua coloração vai do dourado ao vermelho acastanhado ou até mesmo púrpura. A sua consistência é quebradiça. [2] Esta espécie possui um sinónimo, a Xestospongia rampa (de Laubenfels, 1934).
A taxa de crescimento especifico desta espécie encontra-se avaliada entre de 0,52 +/- 0,65 anos-1, podendo assim os especimens maiores ultrapassar os dois mil anos de idade.[3]
Do ponto de vista de distribuição vertical esta esponja é encontrada a partir dos 10 metros de profundidade. São sobretudo encontradas nas Bahamas e Caribe, sendo ocasionalmente encontradas na Califórnia.
Do ponto de vista ecológico esta espécie tem um duplo papel, por um lado serve de abrigo para inúmeros organismos bentónicos, por outro a sua capacidade de filtração de grandes volumes de água, leva a um aumento da claridade da agua, afectado desse modo, a densidade de algas e de corais à sua volta. [4]
Tal como os corais esta esponja possui cianobactérias simbiontes, as quais lhes conferem a cor característica. Estes simbiontes são responsáveis pela ficção de azoto e carbono. Tal como acontece com os corais, estas esponjas podem sofrer o lixiviamento dos seus simbiontes devido a estresses ambientais, nomeadamente estresses antropogénicos. [4][5] De modo a se estudar o fenômeno de lixiviamento na X. muta, em 1997 foi iniciado um estudo de monitorização com 12 pontos de 16 metros de diâmetro ao longo de três profundidades no Santuário Nacional Marinho de Florida Keys. [5]
A Xestospongia muta (em inglês: Giant barrel sponge) é uma megaesponja emblemática associada aos corais tropicais. Apresenta uma função ecológica e comercial (sector do turismos) equivalente aos dos corais, sofrendo de igual modo do fenômeno de lixiviação dos mesmos.
