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鹿回头岸礁造礁石珊瑚物种多样性的研究 总被引:9,自引:4,他引:9
定量分析鹿回头岸礁造礁石珊瑚群落的种类组成,选择α-多样性和β-多样性的度量方法,分析了该群落造礁石珊瑚种、属和科的多样性及其与所处生境的关系。结果表明:鹿回头岸礁造礁石珊瑚群落的物种比较丰富,多样性和均匀度指数都较高,但在不同地段之间存在着明显的差异。水深中等的地段(2.4 ̄5.0m)的多样性指数高于较浅(1.5 ̄2.0m)和较深(5.5 ̄6.5m)地段;潮间带与潮下带之间和礁平台与向海斜坡之间 相似文献
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根据石珊瑚物种的总数、石珊瑚覆盖的百分率、物种多样性和均匀度,对鹿回头岸礁造礁石珊瑚群落结构类型所处在演替阶段的时间状态和生境的空间状态进行分析。在中等和深水区物种多样性的时间变异,随演替的发展而有所下降;浅水区不随演替而变化。在不同生境区珊瑚生长的聚群上,与时间的发展无关;每个演替时期,物种多样性的类型与生境的变化有关。 相似文献
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西沙群岛海域造礁石珊瑚物种多样性与分布特点 总被引:5,自引:0,他引:5
2006年3-5月,采用国际通用的截线样带法对海南省西沙群岛主要珊瑚礁海域的18个岛礁造礁石珊瑚进行了实地调查,共记录13科45属188种,其中62个新记录种.整合文献资料,该海域共记录造礁石珊瑚13科50属204种,基本包括分布在我国(不含台湾省)的所有造礁石珊瑚科属和绝大多数种类.造礁石珊瑚以生长速度快的分枝状珊瑚为主.物种多样性最高的是华光礁海域、金银岛海域和永兴岛海域.聚类分析可以把18个调查岛礁分成3个类群:有人类居住的大型环礁群、独立岛礁群和无人居住的大型环礁群(华光礁).为了有效保护珍稀的造礁石珊瑚资源,按照其种类多样性和分布特点重点保护关键海域是十分必要的. 相似文献
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定量分析鹿回头岸礁造礁石珊瑚群落的种类组成,选择α-多样性和β-多样性的度量方法,分析了该群落造礁石珊瑚种、属和科的多样性及其与所处生境的关系。结果表明:鹿回头岸礁造礁石珊瑚群落的物种比较丰富,多样性和均匀度指数都较高,但在不同地段之间存在着明显的差异。水深中等的地段(2.4~5.0m)的多样性指数高于较浅(1.5~2.0m)和较深(5.5~6.5m)地段;期间带与潮下带之间和礁平台与向海斜坡之间的两个过渡地带的生境条件复杂,物种多样性和种类分布的混杂程度都高于其他地段。 相似文献
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造礁石珊瑚是珊瑚礁框架建造者, 具有维持珊瑚礁生态系统功能和稳定性的重要作用, 其分类对于造礁石珊瑚和珊瑚礁的研究与保护至关重要。目前, 随着分子系统学的不断发展, 造礁石珊瑚的分类体系发生改变, 伴随着出现大量同物异名。近年来也出现许多无中文学名的中国造礁石珊瑚新记录种, 这些都给物种认定和命名带来困难, 阻碍了中国造礁石珊瑚的研究与保护工作。为此, 本文收集了中国造礁石珊瑚物种记录文献资料, 采用最新的造礁石珊瑚分类体系, 确认同物异名, 形成中国造礁石珊瑚物种名录, 并对中国造礁石珊瑚物种的中文名进行统一的规范和命名。结果表明, 中国共有造礁石珊瑚2个类群16科77属445种。与《中国动物志·腔肠动物门·珊瑚虫纲·石珊瑚目·造礁石珊瑚》相比, 科级分类阶元新增7个科, 变更5个科; 属级分类阶元新增26属, 变更1属, 合并3属; 种级分类阶元新增291种, 变更13种, 合并20种, 新命名305个物种的中文名。并且筛选出187个同物异名。此外, 由于造礁石珊瑚分类体系现仍有部分争议, 文章也进行了讨论说明。 相似文献
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珊瑚礁是典型的环境敏感性的海洋生态系统之一,其对环境变化的响应及适应机制的相关研究得到越来越多的关注。了解南海广布型物种鹿角杯形珊瑚(Pocillopora damicornis)的遗传特征有利于深入理解南海珊瑚礁的环境适应机制。本研究基于南海2个典型海域4个调查站点共84个鹿角杯形珊瑚样品,使用7个微卫星标记表征其遗传多样性和遗传结构。遗传多样性指标统计结果显示,南海鹿角杯形珊瑚的遗传多样性水平较低(Ho为0.090~0.567,He为0.137~0.458),海南岛海区与西沙海区的遗传多样性水平差别不大,其中海南岛的鹿回头群体的遗传多样性较高,西沙的银屿群体的遗传多样性最低。遗传结构分析结果显示,南海鹿角杯形珊瑚形成2个遗传分离的谱系:(鹿回头群体、七连屿群体、永兴群体)和银屿群体。曼特尔检验结果表明鹿角杯形珊瑚群体间的遗传分化与平均海表温度(sea surface temperature, SST)(R2=0.312 5,P=0.290)、 SST变异度(R2=0.066 8,P=0.680)... 相似文献
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对三亚鹿回头珊瑚岸礁沿垂直岸线的5条断面上84个调查样方观测照相和室内判读分析,鹿回头岸段石珊瑚共有13科24属69种,珊瑚分布不均,少数种类优势明显.石珊瑚优势种为澄黄滨珊瑚,其重要值百分比为36.62%;优势属为滨珊瑚属(43.85%)和鹿角珊瑚属(22.88%).各断面间多样性格局差异明显,并存在明显的垂直分带现象:东北部第1、2断面石珊瑚种类分布较为均匀,多样性指数值高于中南部第3、4、5断面;礁坪为珊瑚稀疏生长带,种类较少且滨珊瑚为绝对优势属(重要值百分比>50%);礁坡为珊瑚密集生长带,种类较多以鹿角珊瑚最占优势(28.33%),滨珊瑚仅次之(26.71%).近年来该岸段珊瑚礁衰退趋势明显,不合理的破坏性人类活动是重要原因.石珊瑚多样性的空间差异除因礁坪礁坡不同的自然环境外,主要与受到不同类型和强度的人类活动有关.礁坪大潮低潮时暴露,环境恶劣,且受人类采挖、践踏活动影响较频繁和明显;礁坡环境适宜,人类活动影响也相对微弱.养殖、捕捞和近岸排污等人类活动在岸段中南部较为突出,对珊瑚多样性的影响比东北部明显.在尊重珊瑚礁发育的自然规律基础上不断加大力度制止养殖、不合理捕捞和近岸排污等破坏性人类活动,才能更好地科学保护和管理该岸段珊瑚礁. 相似文献
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以涠洲岛造礁石珊瑚群落为研究对象,分析其群落物种组成、多样性、Raunkiaer频度和种间Spearman轶相关,探讨群落组成与水环境因子的相关性,并结合近10年来涠洲岛造礁石珊瑚变化情况,找出涠洲岛造礁石珊瑚群落的主导影响因素。结果表明:(1)近10年来涠洲岛造礁石珊瑚覆盖率显著降低,珊瑚形态组成趋于块状化,尽管珊瑚群落多样性较高,但群落分布较松散,群落结构较不稳定,部分优势种种间竞争较激烈。(2)悬浮物含量是影响石珊瑚群落最显著的环境因子。石珊瑚优势种群在不同水深中分布差异显著,泥沙覆盖率、营养盐对不同石珊瑚种群影响差异较大,大型海藻覆盖率在局部区域对优势珊瑚形成较强的竞争关系。(3)营养盐和泥沙沉积物的增加与涠洲岛近海养殖业及生活排污、海岸工程及海岸侵蚀密切相关。 相似文献
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Marine organisms exhibit great variation in reproductive modes, larval types, and other life-history traits that may have major evolutionary consequences. We measured local and regional patterns of genetic variation in corals along Australia's Great Barrier Reef to determine the relative contributions of sexual and asexual reproduction to recruitment and to infer levels of gene flow both locally (among adjacent sites, < 5 km apart) and regionally (among reefs separated by 500-1,200 km). We selected five common brooding species (Acropora cuneata, A. palifera, Pocillopora damicornis, Seriatopora hystrix, and Stylophora pistillata) and four broadcast spawners (Acropora hyacinthus, A. cytherea, A. millepora, and A. valida), which encompassed a wide range of larval types and potential dispersal capabilities. We found substantial genotypic diversity at local scales in six of the nine species (four brooders, two spawners). For these six, each local population displayed approximately the levels of multilocus genotypic diversity (Go) expected for outcrossed sexual reproduction (mean values of Go:Ge ranged from 0.85 to 1.02), although consistent single-locus heterozygous deficits indicate that inbreeding occurs at the scale of whole reefs. The remaining three species, the brooder S. hystrix and the spawners A. valida and A. millepora displayed significantly less multilocus genotypic diversity (Go) than was expected for outcrossed sexual reproduction (Ge) within each of several sites. Acropora valida and A. millepora showed evidence of extensive localized asexual replication: (1) a small number of multilocus (clonal) genotypes were numerically dominant within some sites (Go:Ge values were as low as 0.17 and 0.20): (2) single-locus genotype frequencies were characterized by both excesses and deficits of heterozygotes (cf. Hardy-Weinberg expectations), and (3) significant linkage disequilibria occurred. For the brooding S. hystrix Go:Ge values were also low within each of four sites (x = 0.48). However, this result most likely reflects the highly restricted dispersal of gametes or larvae, because levels of genetic variation among sites within reefs were extremely high (FSR = 0.28). For all species, we detected considerable genetic subdivision among sites within each reef (high FSR-values), and we infer that larval dispersal is surprisingly limited (i.e., Nem among sites ranging from 0.6 to 3.3 migrants per generation), even in species that have relatively long planktonic durations. Nevertheless, our estimates of allelic variation among reefs (FRT) also imply that for all four broadcast spawning species and three of the brooders, larval dispersal is sufficient to maintain moderate to high levels of gene flow along the entire Great Barrier Reef (i.e., Nem among reefs ranged from 5 to 31). In contrast, widespread populations of S. hystrix and S. pistilata (the two remaining brooders) are relatively weakly connected (Nem among reefs was 1.4 and 2.5, respectively). We conclude that most recruitment by corals is very local, particularly in brooders, but that enough propagules are widely dispersed to ensure that both broadcast spawning and brooding species form vast effectively panmictic populations on the Great Barrier Reef. 相似文献
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DNA BARCODING: Barcoding corals: limited by interspecific divergence, not intraspecific variation 总被引:1,自引:0,他引:1
The expanding use of DNA barcoding as a tool to identify species and assess biodiversity has recently attracted much attention. An attractive aspect of a barcoding method to identify scleractinian species is that it can be utilized on any life stage (larva, juvenile or adult) and is not influenced by phenotypic plasticity unlike morphological methods of species identification. It has been unclear whether the standard DNA barcoding system, based on cytochrome c oxidase subunit 1 (COI), is suitable for species identification of scleractinian corals. Levels of intra- and interspecific genetic variation of the scleractinian COI gene were investigated to determine whether threshold values could be implemented to discriminate conspecifics from other taxa. Overlap between intraspecific variation and interspecific divergence due to low genetic divergence among species (0% in many cases), rather than high levels of intraspecific variation, resulted in the inability to establish appropriate threshold values specific for scleractinians; thus, it was impossible to discern most scleractinian species using this gene. 相似文献
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Daisuke Taira Tai Chong Toh Chin Soon Lionel Ng Hai Xin Loke Lutfi Afiq-Rosli Patrick C. Cabaitan 《Marine and Freshwater Behaviour and Physiology》2017,50(5-6):375-385
The recovery of bleached corals is crucial in ensuring the persistence of the coral reef ecosystem function. This study investigated whether relocating bleached Platygyra sinensis colonies was a viable measure to accelerate their recovery. During a mild bleaching event in 2014, eight bleached colonies of P. sinensis were relocated from an affected reef at Sultan Shoal, Singapore, to a reef at Kusu that was less impacted. Another eight colonies at Sultan Shoal were tagged as controls. After five months, 88% of relocated bleached colonies at Kusu showed full recovery whereas only 25% of the control bleached colonies at Sultan Shoal had recovered. The differential coral recovery among the two sites was most likely due to lower seawater temperatures and faster water flow at Kusu, which helped to mitigate the effects of thermal stress on the bleached corals. This relocation study demonstrated that relocating bleached P. sinensis to sites with more favourable environmental conditions is a viable approach to reduce bleaching impacts for this species. 相似文献
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This study examined the dietary habits and functional composition of butterflyfishes in the Chagos Archipelago, central Indian Ocean. Eighteen species of butterflyfishes were recorded in Chagos, including six obligate corallivores (Chaetodon bennetti, Chaetodon guttatissimus, Chaetodon meyeri, Chaetodon trifascialis, Chaetodon trifasciatus and Chaetodon zanzibarensis), five facultative corallivores (Chaetodon auriga, Chaetodon falcula, Chaetodon interruptus, Chaetodon kleinii and Chaetodon madagaskariensis), two non‐corallivores (Chaetodon lunula and Chaetodon xanthocephalus) and a further five species (Chaetodon citrinellus, Chaetodon lineolatus, Heimitaurichthys zoster, Heniochus monoceros and Forcipiger flavissimus), for which local dietary habits were not studied. There were marked differences in the abundance of butterflyfishes among sites and between reef zones, mostly associated with variation in abundance of scleractinian corals. Obligate coral‐feeding species (mostly C. trifascialis) dominated across all sites. This study suggests that coral feeding and high levels of dietary specialization contribute to high population‐level fitness among coral reef butterflyfishes. Despite being more vulnerable to habitat disturbances and coral loss, it appears likely that specialist coral‐feeding butterflyfishes are also much more resilient to occasional disturbances, and therefore dominate in a wide range of coral reef habitats. 相似文献
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Sexual vs. asexual reproduction in an ecosystem engineer: the massive coral Montastraea annularis 总被引:1,自引:0,他引:1
1. Long-lived sedentary organisms with a massive morphology are often assumed to utilize a storage effect whereby the persistence of a small group of adults can maintain the population when sexual recruitment fails. However, employing storage effects could prove catastrophic if, under changing climatic conditions, the time period between favourable conditions becomes so prolonged that the population cannot be sustained solely be sexual recruitment. When a species has multiple reproductive options, a rapidly changing environment may favour alternative asexual means of propagation. 2. Here, we revisit the importance of asexual dispersal in a massive coral subject to severe climate-induced disturbance. Montastraea annularis is a major framework-builder of Caribbean coral reefs but its survival is threatened by the increasing cover of macroalgae that prevents settlement of coral larvae. 3. To estimate levels of asexual recruitment within populations of M. annularis, samples from three sites in Honduras were genotyped using four, polymorphic microsatellite loci. 4. A total of 114 unique genets were identified with 8% consisting of two or more colonies and an exceptionally large genet at the third site comprising 14 colonies. 5. At least 70% of multicolony genets observed were formed by physical breakage, consistent with storm damage. 6. Our results reveal that long-lived massive corals can propagate using asexual methods even though sexual strategies predominate. 相似文献
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造礁石珊瑚对低温的耐受能力及响应模式 总被引:4,自引:0,他引:4
通过实验室生态模拟,研究了低温胁迫下三亚湾5种造礁石珊瑚(十字牡丹珊瑚、佳丽鹿角珊瑚、花鹿角珊瑚、强壮鹿角珊瑚、澄黄滨珊瑚)的耐受性,分析了造礁石珊瑚对低温的响应模式.结果表明:造礁石珊瑚耐受低温能力与其骨骼类型有关,枝状珊瑚最先死亡,块状珊瑚的耐受能力明显高于枝状珊瑚;14 ℃持续3 d是三亚湾枝状造礁石珊瑚的致死低温;14 ℃持续3 d为块状澄黄滨珊瑚的致白化低温;12 ℃持续10 d为叶片状十字牡丹珊瑚的致死温度;块状澄黄滨珊瑚受到低温胁迫时表面形成粘膜,阻止了珊瑚进一步排出共生虫黄藻. 耐高温的珊瑚对低温也表现出较强的耐受能力,珊瑚对低温胁迫的响应模式与对高温的响应模式基本一致, 即珊瑚首先不伸展触手,紧接着不断释放粘液并排出共生藻,最后白化、死亡. 相似文献
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对造礁石珊瑚与其共生藻共生研究现状及其在全球变化下的适应能力进行较全面的综述.造礁石珊瑚与遗传和生理功能独特的共生藻组成内共生关系是成功演化的范例.近年来对珊瑚共生体的分子系统学研究表明共生藻遗传多样性极为丰富,当前认为共生藻属至少包括8个(A-H)各自包含亚系群的世系或系群.珊瑚-共生藻共生功能体对诸如全球变化引起的海水温度上升等环境变化十分敏感.由于珊瑚以及珊瑚礁面临气候变化的严峻挑战,对珊瑚与其共生藻共生关系和共生功体适应能力的研究将是未来重要的研究领域之一. 相似文献
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Sveinn H. Magnusson Kenneth R. N. Anthony Ruth Reef Michael Kühl Ove Hoegh‐Guldberg 《Journal of phycology》2011,47(4):846-860
Adjusting the light exposure and capture of their symbiotic photosynthetic dinoflagellates (genus Symbiodinium Freud.) is central to the success of reef‐building corals (order Scleractinia) across high spatio‐temporal variation in the light environment of coral reefs. We tested the hypothesis that optical properties of tissues in some coral species can provide light management at the tissue scale comparable to light modulation by colony architecture in other species. We compared within‐tissue scalar irradiance in two coral species from the same light habitat but with contrasting colony growth forms: branching Stylophora pistillata and massive Lobophyllia corymbosa. Scalar irradiance at the level of the symbionts (2 mm into the coral tissues) were <10% of ambient irradiance and nearly identical for the two species, despite substantially different light environments at the tissue surface. In S. pistillata, light attenuation (90% relative to ambient) was observed predominantly at the colony level as a result of branch‐to‐branch self‐shading, while in L. corymbosa, near‐complete light attenuation (97% relative to ambient) was occurring due to tissue optical properties. The latter could be explained partly by differences in photosynthetic pigment content in the symbiont cells and pigmentation in the coral host tissue. Our results demonstrate that different strategies of light modulation at colony, polyp, and cellular levels by contrasting morphologies are equally effective in achieving favorable irradiances at the level of coral photosymbionts. 相似文献