Changes of cnida composition during larval development are described for a scleractinian coral Acropora nasuta. Two types of cnidae, a microbasic b-mastigophore nematocyst and a spirocyst, were observed in planulae; whereas, four types were identified in polyps: microbasic p-mastigophore, holotrichous isorhiza, and the two types of cnidae found in planulae. The cnidae of planulae appeared 3-4 days after fertilization and gradually increased in number until the 8th day. The appearance of cnidae 3-4 days after fertilization and the maximum number of cnidae on the 8th day after fertilization coincided with the period of first settlement and maximum settlement, respectively. On the 15th day of in vitro culture, the number of nematocysts remained, but the spirocysts decreased until they were virtually absent in the larvae. The spirocysts might be used up during the repeated trial of settlement. We supposed that the nematocysts act as a defense against predators, whereas the spirocysts were used for initial attachment to the substrata. The number of cnidae will be a useful indicator to find larval maturity.
{"title":"Changes of cnida composition during planula development of a reef-building coral Acropora nasuta","authors":"T. Hayashibara, T. Kimura, M. Hatta","doi":"10.3755/JCRS.2000.39","DOIUrl":"https://doi.org/10.3755/JCRS.2000.39","url":null,"abstract":"Changes of cnida composition during larval development are described for a scleractinian coral Acropora nasuta. Two types of cnidae, a microbasic b-mastigophore nematocyst and a spirocyst, were observed in planulae; whereas, four types were identified in polyps: microbasic p-mastigophore, holotrichous isorhiza, and the two types of cnidae found in planulae. The cnidae of planulae appeared 3-4 days after fertilization and gradually increased in number until the 8th day. The appearance of cnidae 3-4 days after fertilization and the maximum number of cnidae on the 8th day after fertilization coincided with the period of first settlement and maximum settlement, respectively. On the 15th day of in vitro culture, the number of nematocysts remained, but the spirocysts decreased until they were virtually absent in the larvae. The spirocysts might be used up during the repeated trial of settlement. We supposed that the nematocysts act as a defense against predators, whereas the spirocysts were used for initial attachment to the substrata. The number of cnidae will be a useful indicator to find larval maturity.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132171124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The developmental changes in cnida composition of the coral Pocillopora damicornis was studied. At least two types of microbasic p-mastigophores (type I and type II MpM), large and small holotrichous isorhizas (HI), microbasic b-mastigophores (MbM) and spirocysts were observed in P. damicornis. The nematocyst composition of planulae was similar to that of one or two day old primary polyps, but markedly different from that of adult colonies. The large HI were observed only in planulae and primary polyps. MbM were most abundant in planulae and primary polyps while type I MpM were most abundant in adult colonies. The size of MbM and type II MpM was different between planulae or primary polyps and adult colonies. While large HI were retained at least for one week after settlement, spirocysts appeared to decrease temporarily after settlement. The present observations suggest that large HI are used for defense against predators at early stages of development and spirocysts are used for attachment to the substrate during settlement. The present study showed that the cnida composition and the dimensions of certain types of nematocysts change during the course of development of P. damicornis.
{"title":"Developmental changes in cnida composition of the coral Pocillopora damicornis","authors":"C. Paruntu, K. Hidaka, M. Hidaka","doi":"10.3755/JCRS.2000.23","DOIUrl":"https://doi.org/10.3755/JCRS.2000.23","url":null,"abstract":"The developmental changes in cnida composition of the coral Pocillopora damicornis was studied. At least two types of microbasic p-mastigophores (type I and type II MpM), large and small holotrichous isorhizas (HI), microbasic b-mastigophores (MbM) and spirocysts were observed in P. damicornis. The nematocyst composition of planulae was similar to that of one or two day old primary polyps, but markedly different from that of adult colonies. The large HI were observed only in planulae and primary polyps. MbM were most abundant in planulae and primary polyps while type I MpM were most abundant in adult colonies. The size of MbM and type II MpM was different between planulae or primary polyps and adult colonies. While large HI were retained at least for one week after settlement, spirocysts appeared to decrease temporarily after settlement. The present observations suggest that large HI are used for defense against predators at early stages of development and spirocysts are used for attachment to the substrate during settlement. The present study showed that the cnida composition and the dimensions of certain types of nematocysts change during the course of development of P. damicornis.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"12 8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128864535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coral reefs have been degrading faster than they have been recovering (Done 1992; Ginsburg 1994; Hughes 1994; Grigg and Birkeland 1997; McManus and Vergara 1998; Wilkinson 1993, 1998) and they have been accruing in their degraded states because they achieve alternate stable states of algae instead of corals (Knowlton et al. 1981; Knowlton 1992; Done 1992; Hughes 1994), and because rates of damage are much greater than rates of recovery (Muzik 1985; Birkeland 1997a). With the accumulation of reefs in alternative stable states, the total area of some reefs previously dominated by coral is decreasing over time (Muzik 1985; Knowlton et al. 1981, 1990; Wilkinson 1993), and the balance has been continuously in the negative for corals over the past few decades (LaPointe 1989; Hallock et al. 1993; Birkeland 1997a). Furthermore, human activities are now bringing about environmental changes on a global scale (Smith and Buddemeier 1992; Hoegh-Guldberg 1999; Tsuchiya 1999; Wilkinson et al. 1999) which alter the basic conditions and nature of environmental processes in the domain.
珊瑚礁的退化速度比它们恢复的速度要快(Done 1992;金斯伯格1994;休斯1994;Grigg and Birkeland 1997;McManus and Vergara 1998;Wilkinson 1993,1998)，它们一直在退化状态下积累，因为它们达到了藻类而不是珊瑚的交替稳定状态(Knowlton等人，1981;伟达1992;完成1992;Hughes 1994)，而且因为破坏的速度远远大于恢复的速度(Muzik 1985;Birkeland 1997)。随着交替稳定状态的珊瑚礁的积累，以前由珊瑚主导的一些珊瑚礁的总面积随着时间的推移而减少(Muzik 1985;Knowlton et al. 1981,1990;Wilkinson, 1993)，而在过去的几十年里，珊瑚的平衡一直是负的(LaPointe, 1989;Hallock et al. 1993;Birkeland 1997)。此外，人类活动现在正在全球范围内引起环境变化(Smith和Buddemeier 1992;豪厄格-古尔伯格1999;土屋1999;Wilkinson et al. 1999)，它改变了该领域环境过程的基本条件和性质。
{"title":"The Future of Coral Reefs","authors":"Jc Rs, C. Birkeland","doi":"10.3755/JCRS.2000.13","DOIUrl":"https://doi.org/10.3755/JCRS.2000.13","url":null,"abstract":"Coral reefs have been degrading faster than they have been recovering (Done 1992; Ginsburg 1994; Hughes 1994; Grigg and Birkeland 1997; McManus and Vergara 1998; Wilkinson 1993, 1998) and they have been accruing in their degraded states because they achieve alternate stable states of algae instead of corals (Knowlton et al. 1981; Knowlton 1992; Done 1992; Hughes 1994), and because rates of damage are much greater than rates of recovery (Muzik 1985; Birkeland 1997a). With the accumulation of reefs in alternative stable states, the total area of some reefs previously dominated by coral is decreasing over time (Muzik 1985; Knowlton et al. 1981, 1990; Wilkinson 1993), and the balance has been continuously in the negative for corals over the past few decades (LaPointe 1989; Hallock et al. 1993; Birkeland 1997a). Furthermore, human activities are now bringing about environmental changes on a global scale (Smith and Buddemeier 1992; Hoegh-Guldberg 1999; Tsuchiya 1999; Wilkinson et al. 1999) which alter the basic conditions and nature of environmental processes in the domain.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"210 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134334366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Okinawan coral reefs experienced extensive coral reef bleaching in the summer of 1998 (Fujioka 1999, Taniguchi et al. 1999, Sugihara et al. 1999, Yamazato 1999). Around Sesoko Island (Okinawa, Japan), about 90% of hard corals and soft corals disappeared from the reef flat after the bleaching event (Yamazato 1999). We have been studying early development of zooxanthella-containing eggs of scleractinian corals belonging to the genus Pocillopora since 1997 (Hirose et al. 2000), and studying the incorporation of zooxanthellae into oocytes of Montipora species since 1995 (Hirose et al, in preparation). During the 1999 reproductive season, we tried to observe the early development of Pocillopora verrucosa and Montipora digitata. However, the number of colonies which spawned gametes was low in P. verrucosa, and even when we got a sufficient amount of gametes for fertilization experiments, fertilization rates were extremely low. Szmant and Gassman (1990) reported that corals that remained bleached over an extended period were not able to complete gametogenesis during the reproductive season following the bleaching, while those corals that recovered and regained their zooxanthellae by the next spring were able to follow a normal gametogenic cycle. However, the effects of thermal stress on the reproductive biology of corals are only partly understood (HoeghGuldberg 1999). Here we report preliminary observations on gamete production, the percentage of colonies which spawned gametes, and the fertilization rate of two scleractinian corals, Montipora digitata and Pocillopora verrucosa during the reproductive season following the 1998 bleaching. Both species are hermaphroditic spawners and release zooxanthella-containing eggs (Hirose et al. 2000). While most colonies of P, verrucosa at our collection site died after the 1998-bleaching event, colonies of M, digitata survived, even in shallow waters.
冲绳的珊瑚礁在1998年夏季经历了大面积的珊瑚礁白化(Fujioka 1999, Taniguchi et al. 1999, Sugihara et al. 1999, Yamazato 1999)。在日本冲绳的雪子岛附近，大约90%的硬珊瑚和软珊瑚在白化事件后从礁滩上消失(Yamazato 1999)。我们从1997年开始研究poillopora属硬核珊瑚含虫黄藻卵的早期发育(Hirose et al. 2000)，从1995年开始研究虫黄藻与Montipora种卵母细胞的结合(Hirose et al. in preparation)。在1999年繁殖季节，我们尝试观察了疣状囊孢(Pocillopora verrucosa)和数码囊孢(Montipora digitata)的早期发育。然而，疣藻产生配子的菌落数量很少，即使我们获得了足够数量的配子进行受精实验，受精率也极低。Szmant和Gassman(1990)报告说，长时间保持白化的珊瑚无法在白化后的繁殖季节完成配子发生，而那些在第二年春天恢复并重新获得虫黄藻的珊瑚能够遵循正常的配子发生周期。然而，热应激对珊瑚生殖生物学的影响仅被部分理解(HoeghGuldberg 1999)。本文报道了1998年白化后两种硬核珊瑚(Montipora digitata和Pocillopora verrucosa)繁殖季节配子产量、产生配子的菌落百分比和受精率的初步观察结果。这两个物种都是雌雄同体的产卵者，并释放含有虫黄藻的卵(Hirose et al. 2000)。1998年白化事件发生后，我们收集地点的大部分疣藻都死亡了，而疣藻存活了下来，即使是在浅水区。
{"title":"Reduced reproductive success in scleractinian corals that survived the 1998 bleaching in Okinawa","authors":"M. Hirose, M. Hidaka","doi":"10.3755/JCRS.2000.17","DOIUrl":"https://doi.org/10.3755/JCRS.2000.17","url":null,"abstract":"Okinawan coral reefs experienced extensive coral reef bleaching in the summer of 1998 (Fujioka 1999, Taniguchi et al. 1999, Sugihara et al. 1999, Yamazato 1999). Around Sesoko Island (Okinawa, Japan), about 90% of hard corals and soft corals disappeared from the reef flat after the bleaching event (Yamazato 1999). We have been studying early development of zooxanthella-containing eggs of scleractinian corals belonging to the genus Pocillopora since 1997 (Hirose et al. 2000), and studying the incorporation of zooxanthellae into oocytes of Montipora species since 1995 (Hirose et al, in preparation). During the 1999 reproductive season, we tried to observe the early development of Pocillopora verrucosa and Montipora digitata. However, the number of colonies which spawned gametes was low in P. verrucosa, and even when we got a sufficient amount of gametes for fertilization experiments, fertilization rates were extremely low. Szmant and Gassman (1990) reported that corals that remained bleached over an extended period were not able to complete gametogenesis during the reproductive season following the bleaching, while those corals that recovered and regained their zooxanthellae by the next spring were able to follow a normal gametogenic cycle. However, the effects of thermal stress on the reproductive biology of corals are only partly understood (HoeghGuldberg 1999). Here we report preliminary observations on gamete production, the percentage of colonies which spawned gametes, and the fertilization rate of two scleractinian corals, Montipora digitata and Pocillopora verrucosa during the reproductive season following the 1998 bleaching. Both species are hermaphroditic spawners and release zooxanthella-containing eggs (Hirose et al. 2000). While most colonies of P, verrucosa at our collection site died after the 1998-bleaching event, colonies of M, digitata survived, even in shallow waters.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131669543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated zooxanthellae densities, chlorophyll a and c2 concentrations, and zooxanthellae morphologies in replicate samples of Stylophora pistillata colonies before and during the 1998 coral-bleaching event in Okinawa, Japan. During the bleaching event sea surface temperatures reached 31 °C and Stylophora pistillata colonies supported significantly reduced mean chlorophyll a and c2 concentrations per cm2, and significantly more pale zooxanthellae cells in hospite than before the bleaching. Although the number of healthy zooxanthellae decreased during the coral-bleaching event, the total density of zooxanthellae in S. pistillata colonies (i. e., including the pale zooxanthellae) did not change significantly. Thus, the presence of pale zooxanthellae within colonies numerically compensated for the loss of healthy zooxanthellae. We suggest that pigment degradation in zooxanthellae and subsequent cell shrinkage, rather than zooxanthellae expulsion, was the mechanism involved in S. pistillata bleaching.
{"title":"Changes in zooxanthellae characteristics in the coral Stylophora pistillata during the 1998 bleaching event","authors":"T. Kuroki, R. Woesik","doi":"10.3755/JCRS.1999.97","DOIUrl":"https://doi.org/10.3755/JCRS.1999.97","url":null,"abstract":"This study investigated zooxanthellae densities, chlorophyll a and c2 concentrations, and zooxanthellae morphologies in replicate samples of Stylophora pistillata colonies before and during the 1998 coral-bleaching event in Okinawa, Japan. During the bleaching event sea surface temperatures reached 31 °C and Stylophora pistillata colonies supported significantly reduced mean chlorophyll a and c2 concentrations per cm2, and significantly more pale zooxanthellae cells in hospite than before the bleaching. Although the number of healthy zooxanthellae decreased during the coral-bleaching event, the total density of zooxanthellae in S. pistillata colonies (i. e., including the pale zooxanthellae) did not change significantly. Thus, the presence of pale zooxanthellae within colonies numerically compensated for the loss of healthy zooxanthellae. We suggest that pigment degradation in zooxanthellae and subsequent cell shrinkage, rather than zooxanthellae expulsion, was the mechanism involved in S. pistillata bleaching.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126184425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Kayanne, S. Harii, H. Yamano, M. Tamura, Y. Ide, Fujio Akimoto
Changes in living coral coverage along five transects on Shiraho reef and one transect on Kabira reef, Ishigaki Island, Ryukyu Islands were investigated before and after the 1998 bleaching event. The coverage of living corals after the bleaching decreased by 50% of their original values. Branching types of Montipora, Acropora and Porites were most severely bleached and their mortality was also high. Bleaching was intermediate to high for massive Porites whose recovery was better than branching corals. Heliopora coerulea was less susceptible to bleaching and mortality was low. Higher than 30°C sea surface temperature prevailed over the south sea of Japan, which induced higher than 30°C reef water temperature on the coral reef flat and resulted in coral bleaching.
{"title":"Changes in living coral coverage before and after the 1998 bleaching event on coral reef flats of Ishigaki Island, Ryukyu Islands","authors":"H. Kayanne, S. Harii, H. Yamano, M. Tamura, Y. Ide, Fujio Akimoto","doi":"10.3755/JCRS.1999.73","DOIUrl":"https://doi.org/10.3755/JCRS.1999.73","url":null,"abstract":"Changes in living coral coverage along five transects on Shiraho reef and one transect on Kabira reef, Ishigaki Island, Ryukyu Islands were investigated before and after the 1998 bleaching event. The coverage of living corals after the bleaching decreased by 50% of their original values. Branching types of Montipora, Acropora and Porites were most severely bleached and their mortality was also high. Bleaching was intermediate to high for massive Porites whose recovery was better than branching corals. Heliopora coerulea was less susceptible to bleaching and mortality was low. Higher than 30°C sea surface temperature prevailed over the south sea of Japan, which induced higher than 30°C reef water temperature on the coral reef flat and resulted in coral bleaching.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131088993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The author has witnessed two coral bleaching events taken place at Sesoko and Okinawa islands in 1980 and 1998. Although the final reports of the 1998 event are not accessible, the author tries to make some comparisons among the events according to his own report on the 1980 event (Yamazato 1981) and his personal experiences of the 1998 event. Coral bleaching in 1980 around Sesoko Island, Okinawa, Japan appears to have been a local event, while that of 1998 was much more extensive affecting all islands of the Ryukyu Islands and Southern Kyushu. Abnormally high surface temperatures were observed on the reef flat during daytime low tide in the summer of 1980, while it was observed continuously throughout the summer of 1998, affecting not only coral reef waters but also coastal waters both day and night. In 1980, over 40% of coral colonies bleached once and about 10% died, the rest of the bleached corals recovered by the following January. In the 1998 event, according to visual observations of the author made on the same reef section, almost 90% of corals and soft corals bleached and died, with only a few colonies of a few species that recovered. In addition to these personal observations, some results of new surveys are presented and comparisons between the two events are made.
{"title":"Coral bleaching in Okinawa, 1980 vs 1998","authors":"K. Yamazato","doi":"10.3755/JCRS.1999.83","DOIUrl":"https://doi.org/10.3755/JCRS.1999.83","url":null,"abstract":"The author has witnessed two coral bleaching events taken place at Sesoko and Okinawa islands in 1980 and 1998. Although the final reports of the 1998 event are not accessible, the author tries to make some comparisons among the events according to his own report on the 1980 event (Yamazato 1981) and his personal experiences of the 1998 event. Coral bleaching in 1980 around Sesoko Island, Okinawa, Japan appears to have been a local event, while that of 1998 was much more extensive affecting all islands of the Ryukyu Islands and Southern Kyushu. Abnormally high surface temperatures were observed on the reef flat during daytime low tide in the summer of 1980, while it was observed continuously throughout the summer of 1998, affecting not only coral reef waters but also coastal waters both day and night. In 1980, over 40% of coral colonies bleached once and about 10% died, the rest of the bleached corals recovered by the following January. In the 1998 event, according to visual observations of the author made on the same reef section, almost 90% of corals and soft corals bleached and died, with only a few colonies of a few species that recovered. In addition to these personal observations, some results of new surveys are presented and comparisons between the two events are made.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114267617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A foreword by the President of the Japanese Coral Reef Society","authors":"K. Yamazato","doi":"10.3755/JCRS.1999.1","DOIUrl":"https://doi.org/10.3755/JCRS.1999.1","url":null,"abstract":"","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133210439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We examined whether increased concentration of ammonium or phosphate prevents bleaching in the coral Galaxea fascicularis exposed to a high temperature to test the hypothesis that bleaching occurs when cnidarian hosts fail to supply their symbiotic algae with sufficient inorganic nutrients. Isolated polyps of G. fascicularis were incubated at 32°C for 9 days either in filtered sea water (FSW), 100μM NH4Cl in FSW, or 10μM Na2PO4 in FSW. The density of zooxanthellae and areal concentration of chlorophyll decreased to about a half regardless of when inorganic nutrients were present and absent in the treatments. The present results suggest that the loss of zooxanthellae at a high temperature is not due to a reduction in the supply of inorganic nutrients to zooxanthellae by their host.
{"title":"Does enrichment by inorganic nutrients prevent bleaching in the coral Galaxea fascicularis exposed to high temperature","authors":"M. Hidaka, A. Miyagi","doi":"10.3755/JCRS.1999.3","DOIUrl":"https://doi.org/10.3755/JCRS.1999.3","url":null,"abstract":"We examined whether increased concentration of ammonium or phosphate prevents bleaching in the coral Galaxea fascicularis exposed to a high temperature to test the hypothesis that bleaching occurs when cnidarian hosts fail to supply their symbiotic algae with sufficient inorganic nutrients. Isolated polyps of G. fascicularis were incubated at 32°C for 9 days either in filtered sea water (FSW), 100μM NH4Cl in FSW, or 10μM Na2PO4 in FSW. The density of zooxanthellae and areal concentration of chlorophyll decreased to about a half regardless of when inorganic nutrients were present and absent in the treatments. The present results suggest that the loss of zooxanthellae at a high temperature is not due to a reduction in the supply of inorganic nutrients to zooxanthellae by their host.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131240784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Warning from the coral reefs","authors":"M. Tsuchiya","doi":"10.3755/JCRS.1999.27","DOIUrl":"https://doi.org/10.3755/JCRS.1999.27","url":null,"abstract":"","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114918325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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