As global warming and climate-change proceeds ever more rapidly, organisms depending on seasonal ... more As global warming and climate-change proceeds ever more rapidly, organisms depending on seasonal cues to synchronize reproduction face an unclear future. Reproduction in Diadema setosum in the Gulf of Aqaba (Red Sea) is seasonal, with mature individuals occurring from July to October. Gonad indexes (GI), in contrast, indicate that spawning occurs from August through December and suggests two main spawning events. Histological analysis, however, indicate that the second peak of GI values cannot be related to spawning, but rather correspond to recovering individuals. In Diadema, examination of GI values alone may thus lead to erroneous conclusions. GI was moderately-strong positively correlated with sea-surface temperatures, but not with chlorophyll-a concentrations or photoperiod. Spawning coincides with the onset of the annual chlorophyll-a increase, however, which might be advantageous for nutrition of the developing larvae. First significant GI increase coincides with the shorteni...
International Journal of Systematic and Evolutionary Microbiology, Jul 1, 2001
The aetiological agent of bleaching of the coral Oculina patagonica was characterized as a new Vi... more The aetiological agent of bleaching of the coral Oculina patagonica was characterized as a new Vibrio species on the basis of 16S rDNA sequence, DNA-DNA hybridization data and phenotypic properties, including the cellular fatty acid profile. Based on its 16S rDNA and DNA-DNA hybridization, the new Vibrio species is closely related to Vibrio mediterranei. The name Vibrio shiloi sp. nov. is proposed for the new coral-bleaching species, the type strain being AK1 T (l ATCC BAA-91 T l DSM 13774 T ).
Background: Many fringing coral reefs are exposed to anthropogenically derived eutrophication. In... more Background: Many fringing coral reefs are exposed to anthropogenically derived eutrophication. In scleractinian corals, this type of pollution induces alterations in complex physiological functions, ranging from changes in growth rates and reproductive effort to reduction in immunity, factors that can have dire effects on coral biodiversity. The complexity of effects of eutrophication on coral physiology can be confusing and additional tools are needed to clarify these effects.
Each summer 80-90% of the colonies of Oculina patagonica undergo bleaching off the Mediterranean ... more Each summer 80-90% of the colonies of Oculina patagonica undergo bleaching off the Mediterranean coast of Israel. To investigate fluctuations through a yearly bleaching cycle, monthly measurements of zooxanthella density, mitotic index and chlorophyll- a concentration were conducted. Results showed (1) a significant negative correlation between sea surface temperature (SST) and zooxanthella density; (2) both significantly lower zooxanthella mitotic index and higher chlorophyll -a per zooxanthella content during the bleaching season compared with the non-bleaching period; (3) prior to bleaching, a lag between the peak of zooxanthella density and chlorophyll- a concentration followed by a similar lag during recovery. Zooxanthella density declined significantly between March and May while chlorophyll- a concentration peaked in April, and then declined. Zooxanthella density increased significantly in November while chlorophyll- a concentration increased significantly in January. We conclude that during bacterial bleaching events, zooxanthellae are severely damaged. However, by the time of the following bleaching event the coral tissues regain their “normal” (pre-bleaching) zooxanthella population density.
The pathways of 14C incorporation into the three major compartments of the coral body were analys... more The pathways of 14C incorporation into the three major compartments of the coral body were analysed in colonies of StSophora pistillata. We used the "optic glass-fiber method" to carry out two sets of experiments: in the first, 11 different colonies were sampled immediately after incubation; in the second, 3 colonies were returned to the reef at the termination of incubation for a further period of 29 h. Within the tissue compartment, significantly more 14C labeled products were incorporated into illuminated tips or bases than into unilluminated sections. Tips located above illuminated bases contained amounts of ~4C products similar to unilluminated tips. Within the organic matrix compartment, illumination of tip or base segments again resulted in increased amounts of ~4C fixation, and again unilluminated tips located above the illuminated bases did not accumulate more ~4C photosynthates than other tips on the same branches. The absence of detectable translocation was also confirmed after a post-incubation period of 29 h, and raises questions as to the validity of the widely accepted theory of "upward translocation". Within the skeletal carbonate compartment, although the results were associated with a high coefficient of variation, significantly more ~4C accumulated in the tips than in the bases. Illumination of tips or bases did not enhance ~4C uptake. A light-independent carbon assimilation (dark fixation) is significant in S. pistillata within the three tested compartments (the tissue, the organic matrix of the skeleton, and the skeletal carbonate). It is suggested that the dark fixation process in corals is a result of accumulation of respiratory CO2 and CO2 from sea water as malate or other titratable acids during the night. During the day these acids are broken down, releasing free CO2 for C3 pathway photosynthesis.
... Shmuel Carmely,t Miriam Cojocaru,f Yossi Loya,s and Yoel Kashman*+ School of Chemistry, Tel A... more ... Shmuel Carmely,t Miriam Cojocaru,f Yossi Loya,s and Yoel Kashman*+ School of Chemistry, Tel Aviv University, Ramat Aviv 69978, Israel ... 1. On the basis of the hypothesis that all five compounds, 3-7, are formed from a common biosynthetic precursor (Scheme I, m), we suggest ...
Cellular and Molecular Life Sciences Cmls, Jan 2, 1986
Decreases in two physiological processes (reproduction and growth) have been shown to precede the... more Decreases in two physiological processes (reproduction and growth) have been shown to precede the advent of colony death in the branching coral Stylophora pistillata. These diminutions were sometimes detectable even 6 months and more before any first visible sign of tissue mortality was observed.
Coral reefs can experience extreme salinity changes, particularly hypo-salinity, as a result of s... more Coral reefs can experience extreme salinity changes, particularly hypo-salinity, as a result of storms, heavy rainy seasons (e.g., monsoons), and coastal runoff. Field and laboratory observations have documented that corals exposed to hypo-saline conditions can undergo extensive bleaching and mortality. There is controversy in the literature as to whether hypo-saline conditions induce a pathological response in corals, and if there is a relationship between decreasing salinity treatment and pathological responses. To test the hypothesis that hypo-salinity exposure does not have a pathological effect on coral, we used histological and cellular diagnostic methods to characterize the pathology in hypo-salinity-exposed corals. Colonies of Stylophora pistillata were exposed to five salinity concentrations [39 parts per thousand (ppt), 32 ppt, 28 ppt, 24 ppt, and 20 ppt] that may realistically occur on a reef. Histological examination indicated an increasing severity of pathomorphologies associated with decreasing salinity, including increased tissue swelling, degradation and loss of zooxanthellae, and tissue necrosis. Pulse-amplitude modulated chlorophyll fluorimetry kinetics demonstrated a decreasing photosynthetic efficiency with decreasing salinity conditions. Cytochrome P450 levels were affected by even slight changes in salinity concentration suggesting that detoxification pathways, as well as several endocrine pathways, may be adversely affected. Finally, these studies demonstrated that hypo-saline conditions can induce an oxidative-stress response in both the host and in its algal symbiont, and in so doing, may synergistically increase oxidative-stress burdens. As with other types of environmental stresses, exposure to hypo-saline conditions may have long-term consequences on coral physiology.
To understand how regeneration in corals may be aected by intrinsic and extrinsic factors, the pr... more To understand how regeneration in corals may be aected by intrinsic and extrinsic factors, the process of repair of experimentally induced tissue lesions was investigated in the solitary scleractinian coral Fungia granulosa. Three lesion sizes were in¯icted in situ on large, sexually mature individuals (>5.5 cm diameter) and in small sexually immature (<5.0 cm) individuals. Repair was monitored using photography and computerized image analysis. This procedure was carried out in fall (September to November; post-reproductive months), and repeated with a new set of corals in spring (March to May; gametogenic months). Reproductive eort was investigated histologically 1 to 2 months following lesion in¯iction. In ®eld experiments, there was a signi®cant dierence in percent of tissue coverage 8 weeks after lesion in¯iction between spring and fall for all lesion sizes in large corals. During the fall, all lesion sizes in large corals were repaired within 8 weeks. Large lesions in small corals did not undergo repair regardless of season. During the spring, none of the corals underwent complete repair regardless of coral size, and many of the small corals died. In laboratory experiments, 83.3% of the corals kept at 25°C and 16.7% of those kept at 21°C underwent repair during the fall. None of the corals maintained at 21°C and only 16.7% of those corals maintained at 25°C underwent complete repair during spring. Though both fecundity and tissue regeneration were signi®cantly reduced, gametogenesis continued in corals that had previously undergone experimental injury. These results indicate that in fungiid corals, regeneration is aected by intrinsic factors such as size and reproductive state as well as by envi-ronmental factors such as ambient water temperatures. Moreover, it is possible that, following injury, energetic resources are diverted from repair towards the maintenance of reproductive eort.
Aviv Uniurrrity, Ramat Aviv 69978, Tel Aviv, Israel Ass~~~cr.--Six new avarol and avarone derivat... more Aviv Uniurrrity, Ramat Aviv 69978, Tel Aviv, Israel Ass~~~cr.--Six new avarol and avarone derivatives, 3'-hydroxyavarone [3}, 3',6'dihydroxyavarone [4], 6'-hydroxyavarol[5], 6'-acetoxyavarol[61,6'-acetoxyavarone m, and 6'-hydroxy4'-rnethoxyavarone 181, are reported from the Red Sea sponge Dysidu cinma. The structures of the new compounds were determined by spectroscopic data, mainly 1D and 2D n m r measurements. The absolute configurations of 5,6, and 7, and most likely also of 5 4 , and 8, were established on the basis of cd measurements to be the same as that of avarol. Several of the new compounds are cytotoxic, possess antimicrobial activities, and have anti-HIV-1 reverse transcriptase activities; the most active is compound 8.
Echinoid bioerosion is ecologically important as a limiting factor for reef growth. Diadema setos... more Echinoid bioerosion is ecologically important as a limiting factor for reef growth. Diadema setosum and Echinometra mathaei are the most abundant sea urchins in the Gulf of Eilat, Red Sea. Bioerosion by these urchins was estimated from field experiments with urchins placed in underwater chambers. A novel methodology was developed for measuring the CaC03 content of fecal pellets and total gut contents. This method is based on measurement of the amount of gas formed by total acidification of a mixed sample. The population density of the urchins was determined for the reef flat (depth 0.6-l m) and the reef slope (depth 6-8 m). D. setosum, which erodes 3 10 mg individual-' d-', is much less abundant on the reef flat (0.1 individuals mP2) than on the reef slope (6.4 individuals me*). In contrast, E. mathaei, which erodes 120 mg individual-' dP', is more dominant on the reef flat (10.5 individuals m-*) than on the reef slope (3.7 individuals m-*). We estimate that echinoid bioerosion converts to carbonate sediments 7%-1 1% of the total reef flat calcification and 13%-22% of the total reef slope calcification. These findings emphasize the importance of echinoid bioerosion as a structuring force in the coral reef, and its potential importance to the dynamics of reef development. However, they imply that some previous studies may have overestimated the role of echinoid bioerosion, thus possibly underestimating internal bioerosion.
... However, these studies have focused almost entirely on the organisms&amp;#39; trapping el... more ... However, these studies have focused almost entirely on the organisms&amp;#39; trapping elements (but, for effects of body-induced eddies, see Patterson 1984; Shimeta and Jumars 1991). ... Favia doreyensis L L L A C Montipora danae L L L A C Montipora lobulata L L L A C ...
As global warming and climate-change proceeds ever more rapidly, organisms depending on seasonal ... more As global warming and climate-change proceeds ever more rapidly, organisms depending on seasonal cues to synchronize reproduction face an unclear future. Reproduction in Diadema setosum in the Gulf of Aqaba (Red Sea) is seasonal, with mature individuals occurring from July to October. Gonad indexes (GI), in contrast, indicate that spawning occurs from August through December and suggests two main spawning events. Histological analysis, however, indicate that the second peak of GI values cannot be related to spawning, but rather correspond to recovering individuals. In Diadema, examination of GI values alone may thus lead to erroneous conclusions. GI was moderately-strong positively correlated with sea-surface temperatures, but not with chlorophyll-a concentrations or photoperiod. Spawning coincides with the onset of the annual chlorophyll-a increase, however, which might be advantageous for nutrition of the developing larvae. First significant GI increase coincides with the shorteni...
International Journal of Systematic and Evolutionary Microbiology, Jul 1, 2001
The aetiological agent of bleaching of the coral Oculina patagonica was characterized as a new Vi... more The aetiological agent of bleaching of the coral Oculina patagonica was characterized as a new Vibrio species on the basis of 16S rDNA sequence, DNA-DNA hybridization data and phenotypic properties, including the cellular fatty acid profile. Based on its 16S rDNA and DNA-DNA hybridization, the new Vibrio species is closely related to Vibrio mediterranei. The name Vibrio shiloi sp. nov. is proposed for the new coral-bleaching species, the type strain being AK1 T (l ATCC BAA-91 T l DSM 13774 T ).
Background: Many fringing coral reefs are exposed to anthropogenically derived eutrophication. In... more Background: Many fringing coral reefs are exposed to anthropogenically derived eutrophication. In scleractinian corals, this type of pollution induces alterations in complex physiological functions, ranging from changes in growth rates and reproductive effort to reduction in immunity, factors that can have dire effects on coral biodiversity. The complexity of effects of eutrophication on coral physiology can be confusing and additional tools are needed to clarify these effects.
Each summer 80-90% of the colonies of Oculina patagonica undergo bleaching off the Mediterranean ... more Each summer 80-90% of the colonies of Oculina patagonica undergo bleaching off the Mediterranean coast of Israel. To investigate fluctuations through a yearly bleaching cycle, monthly measurements of zooxanthella density, mitotic index and chlorophyll- a concentration were conducted. Results showed (1) a significant negative correlation between sea surface temperature (SST) and zooxanthella density; (2) both significantly lower zooxanthella mitotic index and higher chlorophyll -a per zooxanthella content during the bleaching season compared with the non-bleaching period; (3) prior to bleaching, a lag between the peak of zooxanthella density and chlorophyll- a concentration followed by a similar lag during recovery. Zooxanthella density declined significantly between March and May while chlorophyll- a concentration peaked in April, and then declined. Zooxanthella density increased significantly in November while chlorophyll- a concentration increased significantly in January. We conclude that during bacterial bleaching events, zooxanthellae are severely damaged. However, by the time of the following bleaching event the coral tissues regain their “normal” (pre-bleaching) zooxanthella population density.
The pathways of 14C incorporation into the three major compartments of the coral body were analys... more The pathways of 14C incorporation into the three major compartments of the coral body were analysed in colonies of StSophora pistillata. We used the "optic glass-fiber method" to carry out two sets of experiments: in the first, 11 different colonies were sampled immediately after incubation; in the second, 3 colonies were returned to the reef at the termination of incubation for a further period of 29 h. Within the tissue compartment, significantly more 14C labeled products were incorporated into illuminated tips or bases than into unilluminated sections. Tips located above illuminated bases contained amounts of ~4C products similar to unilluminated tips. Within the organic matrix compartment, illumination of tip or base segments again resulted in increased amounts of ~4C fixation, and again unilluminated tips located above the illuminated bases did not accumulate more ~4C photosynthates than other tips on the same branches. The absence of detectable translocation was also confirmed after a post-incubation period of 29 h, and raises questions as to the validity of the widely accepted theory of "upward translocation". Within the skeletal carbonate compartment, although the results were associated with a high coefficient of variation, significantly more ~4C accumulated in the tips than in the bases. Illumination of tips or bases did not enhance ~4C uptake. A light-independent carbon assimilation (dark fixation) is significant in S. pistillata within the three tested compartments (the tissue, the organic matrix of the skeleton, and the skeletal carbonate). It is suggested that the dark fixation process in corals is a result of accumulation of respiratory CO2 and CO2 from sea water as malate or other titratable acids during the night. During the day these acids are broken down, releasing free CO2 for C3 pathway photosynthesis.
... Shmuel Carmely,t Miriam Cojocaru,f Yossi Loya,s and Yoel Kashman*+ School of Chemistry, Tel A... more ... Shmuel Carmely,t Miriam Cojocaru,f Yossi Loya,s and Yoel Kashman*+ School of Chemistry, Tel Aviv University, Ramat Aviv 69978, Israel ... 1. On the basis of the hypothesis that all five compounds, 3-7, are formed from a common biosynthetic precursor (Scheme I, m), we suggest ...
Cellular and Molecular Life Sciences Cmls, Jan 2, 1986
Decreases in two physiological processes (reproduction and growth) have been shown to precede the... more Decreases in two physiological processes (reproduction and growth) have been shown to precede the advent of colony death in the branching coral Stylophora pistillata. These diminutions were sometimes detectable even 6 months and more before any first visible sign of tissue mortality was observed.
Coral reefs can experience extreme salinity changes, particularly hypo-salinity, as a result of s... more Coral reefs can experience extreme salinity changes, particularly hypo-salinity, as a result of storms, heavy rainy seasons (e.g., monsoons), and coastal runoff. Field and laboratory observations have documented that corals exposed to hypo-saline conditions can undergo extensive bleaching and mortality. There is controversy in the literature as to whether hypo-saline conditions induce a pathological response in corals, and if there is a relationship between decreasing salinity treatment and pathological responses. To test the hypothesis that hypo-salinity exposure does not have a pathological effect on coral, we used histological and cellular diagnostic methods to characterize the pathology in hypo-salinity-exposed corals. Colonies of Stylophora pistillata were exposed to five salinity concentrations [39 parts per thousand (ppt), 32 ppt, 28 ppt, 24 ppt, and 20 ppt] that may realistically occur on a reef. Histological examination indicated an increasing severity of pathomorphologies associated with decreasing salinity, including increased tissue swelling, degradation and loss of zooxanthellae, and tissue necrosis. Pulse-amplitude modulated chlorophyll fluorimetry kinetics demonstrated a decreasing photosynthetic efficiency with decreasing salinity conditions. Cytochrome P450 levels were affected by even slight changes in salinity concentration suggesting that detoxification pathways, as well as several endocrine pathways, may be adversely affected. Finally, these studies demonstrated that hypo-saline conditions can induce an oxidative-stress response in both the host and in its algal symbiont, and in so doing, may synergistically increase oxidative-stress burdens. As with other types of environmental stresses, exposure to hypo-saline conditions may have long-term consequences on coral physiology.
To understand how regeneration in corals may be aected by intrinsic and extrinsic factors, the pr... more To understand how regeneration in corals may be aected by intrinsic and extrinsic factors, the process of repair of experimentally induced tissue lesions was investigated in the solitary scleractinian coral Fungia granulosa. Three lesion sizes were in¯icted in situ on large, sexually mature individuals (>5.5 cm diameter) and in small sexually immature (<5.0 cm) individuals. Repair was monitored using photography and computerized image analysis. This procedure was carried out in fall (September to November; post-reproductive months), and repeated with a new set of corals in spring (March to May; gametogenic months). Reproductive eort was investigated histologically 1 to 2 months following lesion in¯iction. In ®eld experiments, there was a signi®cant dierence in percent of tissue coverage 8 weeks after lesion in¯iction between spring and fall for all lesion sizes in large corals. During the fall, all lesion sizes in large corals were repaired within 8 weeks. Large lesions in small corals did not undergo repair regardless of season. During the spring, none of the corals underwent complete repair regardless of coral size, and many of the small corals died. In laboratory experiments, 83.3% of the corals kept at 25°C and 16.7% of those kept at 21°C underwent repair during the fall. None of the corals maintained at 21°C and only 16.7% of those corals maintained at 25°C underwent complete repair during spring. Though both fecundity and tissue regeneration were signi®cantly reduced, gametogenesis continued in corals that had previously undergone experimental injury. These results indicate that in fungiid corals, regeneration is aected by intrinsic factors such as size and reproductive state as well as by envi-ronmental factors such as ambient water temperatures. Moreover, it is possible that, following injury, energetic resources are diverted from repair towards the maintenance of reproductive eort.
Aviv Uniurrrity, Ramat Aviv 69978, Tel Aviv, Israel Ass~~~cr.--Six new avarol and avarone derivat... more Aviv Uniurrrity, Ramat Aviv 69978, Tel Aviv, Israel Ass~~~cr.--Six new avarol and avarone derivatives, 3'-hydroxyavarone [3}, 3',6'dihydroxyavarone [4], 6'-hydroxyavarol[5], 6'-acetoxyavarol[61,6'-acetoxyavarone m, and 6'-hydroxy4'-rnethoxyavarone 181, are reported from the Red Sea sponge Dysidu cinma. The structures of the new compounds were determined by spectroscopic data, mainly 1D and 2D n m r measurements. The absolute configurations of 5,6, and 7, and most likely also of 5 4 , and 8, were established on the basis of cd measurements to be the same as that of avarol. Several of the new compounds are cytotoxic, possess antimicrobial activities, and have anti-HIV-1 reverse transcriptase activities; the most active is compound 8.
Echinoid bioerosion is ecologically important as a limiting factor for reef growth. Diadema setos... more Echinoid bioerosion is ecologically important as a limiting factor for reef growth. Diadema setosum and Echinometra mathaei are the most abundant sea urchins in the Gulf of Eilat, Red Sea. Bioerosion by these urchins was estimated from field experiments with urchins placed in underwater chambers. A novel methodology was developed for measuring the CaC03 content of fecal pellets and total gut contents. This method is based on measurement of the amount of gas formed by total acidification of a mixed sample. The population density of the urchins was determined for the reef flat (depth 0.6-l m) and the reef slope (depth 6-8 m). D. setosum, which erodes 3 10 mg individual-' d-', is much less abundant on the reef flat (0.1 individuals mP2) than on the reef slope (6.4 individuals me*). In contrast, E. mathaei, which erodes 120 mg individual-' dP', is more dominant on the reef flat (10.5 individuals m-*) than on the reef slope (3.7 individuals m-*). We estimate that echinoid bioerosion converts to carbonate sediments 7%-1 1% of the total reef flat calcification and 13%-22% of the total reef slope calcification. These findings emphasize the importance of echinoid bioerosion as a structuring force in the coral reef, and its potential importance to the dynamics of reef development. However, they imply that some previous studies may have overestimated the role of echinoid bioerosion, thus possibly underestimating internal bioerosion.
... However, these studies have focused almost entirely on the organisms&amp;#39; trapping el... more ... However, these studies have focused almost entirely on the organisms&amp;#39; trapping elements (but, for effects of body-induced eddies, see Patterson 1984; Shimeta and Jumars 1991). ... Favia doreyensis L L L A C Montipora danae L L L A C Montipora lobulata L L L A C ...
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