Publikationsansicht. 6692797. The importance of competition among small Agaricia in shallow Carib... more Publikationsansicht. 6692797. The importance of competition among small Agaricia in shallow Caribbean reefs and possible factors determining competitive outcome /--by Carla Zilberberg. (2001). Zilberberg, Carla. Abstract. Spine ...
Phycosphere is the region where algal exudates influence microbial communities. Since the term wa... more Phycosphere is the region where algal exudates influence microbial communities. Since the term was coined, research has been focused on understanding free-living-phytoplankton and bacteria interactions. Coral-Symbiodiniaceae symbiosis and its associated microbiomes have also been widely studied due to the increasing number of global and local threats endangering coral reefs worldwide. Nevertheless, little is known about the specific interactions between Symbiodiniaceae and bacterial communities within a coral host. In this review, we focus on Symbiodiniaceae-bacteria relationships, occurring in a zone we call here ‘Symbiodiniaceae phycosphere’, within the coral holobiont, in view of 1) identifying and outlining Symbiodiniaceae-bacteria interactions; 2) highlighting interkingdom signaling among phycosphere partners and 3) characterizing microbiome diversity and its relevance to ‘Symbiodiniaceae phycosphere’ as an adaptability generator. Since free-living Symbiodiniaceae are associated with a diverse, structured and dynamic microbial community that are attracted by chemotaxis to the microalgae exudates’ gradient, the maintenance of this gradient and its effect on the microbiota inside the coral host is a must. Here, we raise evidence that sustains the ‘Symbiodiniaceae phycosphere’ as a relevant portion of the coral holobiont, where essential roles in the holobiont’s fitness, acclimatization, adaptability and survival are presented, both in homeostatic and adverse conditions.
Members of the azooxanthellate coral genus Tubastraea are invasive species with particular concer... more Members of the azooxanthellate coral genus Tubastraea are invasive species with particular concern because they have become established and are fierce competitors in the invaded areas in many parts of the world. Pacific Tubastraea species are spreading fast throughout the Atlantic Ocean, occupying over 95% of the available substrate in some areas and out-competing native endemic species. Approximately half of all known coral species are azooxanthellate but these are seriously under-represented compared to zooxanthellate corals in terms of the availability of mitochondrial (mt) genome data. In the present study, the complete mt DNA sequences of Atlantic individuals of the invasive scleractinian species Tubastraea coccinea and Tubastraea tagusensis were determined and compared to the GenBank reference sequence available for a Pacific "T. coccinea" individual. At 19,094bp (compared to 19,070bp for the GenBank specimen), the mt genomes assembled for the Atlantic T. coccinea and T. tagusensis were among the longest sequence determined to date for "Complex" scleractinians. Comparisons of genomes data showed that the "T. coccinea" sequence deposited on GenBank was more closely related to that from Dendrophyllia arbuscula than to the Atlantic Tubastraea spp., in terms of genome length and base pair similarities. This was confirmed by phylogenetic analysis, suggesting that the former was misidentified and might actually be a member from the genus Dendrophyllia. In addition, although in general the COX1 locus has a slow evolutionary rate in Scleractinia, it was the most variable region of the Tubastraea mt genome and can be used as markers for genus or species identification. Given the limited data available for azooxanthellate corals, the results presented here represent an important contribution to our understanding of phylogenetic relationships and the evolutionary history of the Scleractinia.
Journal of the Marine Biological Association of the United Kingdom, Dec 1, 2007
Chondrilla nucula is a morphologically simple species defined by the presence of spherasters in i... more Chondrilla nucula is a morphologically simple species defined by the presence of spherasters in its skeleton. For a long time C. nucula was considered a cosmopolitan species, however, in 1999, a molecular study demonstrated the existence of a species complex with at least four cryptic species, besides C. nucula. At that time, those four new species were not formally described because the morphological differences observed did not reflect species differences and were attributed to plasticity. Since then, researchers working on Chondrilla species suggested that the skeletal organization, the distribution of spherulous cells and the type of surface should be used to differentiate species. Individuals of Chondrilla aff. nucula from one population in Arraial do Cabo, Rio de Janeiro State, Brazil, were collected monthly and analysed in order to test the validity of those three characters to separate the species of Chondrilla. Moreover, to determine if the differences in spicule dimensions previously found were seasonal, we also quantified the diameter of the spherasters throughout the year. Our results demonstrate that all analysed characters are extremely variable and that spicule size can vary even at the same locality. The present study shows the importance of testing the variability of morphological characters before describing new species. Unfortunately, until valid taxonomic characters are found, the Atlantic Chondrilla species will have to remain undescribed.
Publikationsansicht. 6692797. The importance of competition among small Agaricia in shallow Carib... more Publikationsansicht. 6692797. The importance of competition among small Agaricia in shallow Caribbean reefs and possible factors determining competitive outcome /--by Carla Zilberberg. (2001). Zilberberg, Carla. Abstract. Spine ...
Phycosphere is the region where algal exudates influence microbial communities. Since the term wa... more Phycosphere is the region where algal exudates influence microbial communities. Since the term was coined, research has been focused on understanding free-living-phytoplankton and bacteria interactions. Coral-Symbiodiniaceae symbiosis and its associated microbiomes have also been widely studied due to the increasing number of global and local threats endangering coral reefs worldwide. Nevertheless, little is known about the specific interactions between Symbiodiniaceae and bacterial communities within a coral host. In this review, we focus on Symbiodiniaceae-bacteria relationships, occurring in a zone we call here ‘Symbiodiniaceae phycosphere’, within the coral holobiont, in view of 1) identifying and outlining Symbiodiniaceae-bacteria interactions; 2) highlighting interkingdom signaling among phycosphere partners and 3) characterizing microbiome diversity and its relevance to ‘Symbiodiniaceae phycosphere’ as an adaptability generator. Since free-living Symbiodiniaceae are associated with a diverse, structured and dynamic microbial community that are attracted by chemotaxis to the microalgae exudates’ gradient, the maintenance of this gradient and its effect on the microbiota inside the coral host is a must. Here, we raise evidence that sustains the ‘Symbiodiniaceae phycosphere’ as a relevant portion of the coral holobiont, where essential roles in the holobiont’s fitness, acclimatization, adaptability and survival are presented, both in homeostatic and adverse conditions.
Members of the azooxanthellate coral genus Tubastraea are invasive species with particular concer... more Members of the azooxanthellate coral genus Tubastraea are invasive species with particular concern because they have become established and are fierce competitors in the invaded areas in many parts of the world. Pacific Tubastraea species are spreading fast throughout the Atlantic Ocean, occupying over 95% of the available substrate in some areas and out-competing native endemic species. Approximately half of all known coral species are azooxanthellate but these are seriously under-represented compared to zooxanthellate corals in terms of the availability of mitochondrial (mt) genome data. In the present study, the complete mt DNA sequences of Atlantic individuals of the invasive scleractinian species Tubastraea coccinea and Tubastraea tagusensis were determined and compared to the GenBank reference sequence available for a Pacific "T. coccinea" individual. At 19,094bp (compared to 19,070bp for the GenBank specimen), the mt genomes assembled for the Atlantic T. coccinea and T. tagusensis were among the longest sequence determined to date for "Complex" scleractinians. Comparisons of genomes data showed that the "T. coccinea" sequence deposited on GenBank was more closely related to that from Dendrophyllia arbuscula than to the Atlantic Tubastraea spp., in terms of genome length and base pair similarities. This was confirmed by phylogenetic analysis, suggesting that the former was misidentified and might actually be a member from the genus Dendrophyllia. In addition, although in general the COX1 locus has a slow evolutionary rate in Scleractinia, it was the most variable region of the Tubastraea mt genome and can be used as markers for genus or species identification. Given the limited data available for azooxanthellate corals, the results presented here represent an important contribution to our understanding of phylogenetic relationships and the evolutionary history of the Scleractinia.
Journal of the Marine Biological Association of the United Kingdom, Dec 1, 2007
Chondrilla nucula is a morphologically simple species defined by the presence of spherasters in i... more Chondrilla nucula is a morphologically simple species defined by the presence of spherasters in its skeleton. For a long time C. nucula was considered a cosmopolitan species, however, in 1999, a molecular study demonstrated the existence of a species complex with at least four cryptic species, besides C. nucula. At that time, those four new species were not formally described because the morphological differences observed did not reflect species differences and were attributed to plasticity. Since then, researchers working on Chondrilla species suggested that the skeletal organization, the distribution of spherulous cells and the type of surface should be used to differentiate species. Individuals of Chondrilla aff. nucula from one population in Arraial do Cabo, Rio de Janeiro State, Brazil, were collected monthly and analysed in order to test the validity of those three characters to separate the species of Chondrilla. Moreover, to determine if the differences in spicule dimensions previously found were seasonal, we also quantified the diameter of the spherasters throughout the year. Our results demonstrate that all analysed characters are extremely variable and that spicule size can vary even at the same locality. The present study shows the importance of testing the variability of morphological characters before describing new species. Unfortunately, until valid taxonomic characters are found, the Atlantic Chondrilla species will have to remain undescribed.
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Papers by Carla Zilberberg