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11.
There have been divergent opinions on whether Conophyllia develops synapticulae and dissepiments since its erection in 1849, with different views existing on the morphology of columella in Conophyllia.This paper presents a comprehensive review of Conophyllia, and revises the diagnosis according to new material from the Renacuo area of Gêrzê, Tibet.The revised diagnosis emphasises the following features: solitary coral; abundant radial elements subequal in thickness, lateral faces with granules and synapticulae; parietal, papillar or incompact columella, a few species lacking in columella; developed dissepiments.Individuals of Conophyllia have laminar septa of Triadophyllum type in earlier ontogenetic stages, while their septa in later ontogenetic stages are more fenestrate.The geological and geographical distribution of this genus is discussed, with five species of Conophylliafrom the Renacuo area of Gêrzê, Tibet being described and illustrated, including one new species and two in open nomenclatue. 相似文献
12.
M.S. Pratchett T.J. Schenk M. Baine C. Syms A.H. Baird 《Marine environmental research》2009,67(4-5):230-236
Population outbreaks of crown-of-thorns sea star (Acanthaster planci L.) remain one of the most significant biological disturbances on tropical coral reefs although the increasing attention given to other threats has greatly limited recent progress in understanding the cause and consequences of this phenomenon. In September 2005 dramatic increases in the abundance of A. planci were observed on reefs within Bootless Bay, Central Province, Papua New Guinea, where few crown-of-thorns have previously been reported. Densities of A. planci peaked at 162 sea stars per hectare and caused extensive coral mortality. This outbreak killed upwards of 55% of live corals, reducing overall coral cover from 42.4% in 2005 down to just 19.1% in March 2006. Declines in coral cover were largely driven by widespread mortality of Acropora spp. which dominated reef assemblages prior to the outbreak. The extensive depletion of Acropora spp. greatly altered the coral composition as well as the physical structure of reef habitats. In the absence of any other major disturbances these coral communities are likely to quickly recover, but this outbreak highlights the ongoing contribution of A. planci to degradation of coral reef environments. 相似文献
13.
海南岛西北部海域珊瑚礁造礁石珊瑚种类组成与分布 总被引：1，自引：0，他引：1
调查了海南岛西北部海域造礁石珊瑚种类的多样性及分布.结果表明:共发现50种造礁石珊瑚和1种多孔螅.海南岛西北部造礁石珊瑚优势种为澄黄滨珊瑚(Porites lutea)和丛生盔形珊瑚(Galaxea fascicularis),与历史资料相比优势种发生明显变化;海南岛西北部海域造礁石珊瑚覆盖率急剧下降,是由自然因素和人为活动共同造成;海南岛西北部海域是北部湾、琼州海峡和南海的重要交汇点,可能是造礁石珊瑚幼虫扩散的重要通道,对华南沿岸造礁石珊瑚资源自然恢复起到重要作用.因此,未来的海洋管理应该加强对珊瑚礁的保护力度,开发利用与环境保护并重,这样才能有效保护海南岛西北部海域的珊瑚礁. 相似文献
14.
通过nlsrDNA(nuclear large-subunit ribosomal DNA)及nssrDNA(nuclear small-subunit ribosomal DNA)的PCR-RFLP研究广东徐闻地区8科15属25种62个造礁石珊瑚样本的共生藻。结果表明,共生藻nlsrDNA的RsaI酶切基因型只存在一种,属于C系群共生藻;而nssrDNA的MobⅠ和TaqⅠ两种酶切都存在两种基因型。实验进一步通过PCR直接测序法得到62个造礁石珊瑚样品的共生藻ITS序列,与GenBank上的4种虫黄藻ITS序列构建Neighbor-Joining系统发育树,结果表明该区的造礁石珊瑚共生两种不同种类(亚系群)的共生藻,分别为C1亚系群与C15亚系群共生藻,两个亚系群间的遗传距离为0.019。广东徐闻地区造礁石珊瑚共生藻多样性偏低,暗示该地区珊瑚礁生态系统应对环境变化的能力可能较弱。 相似文献
15.
Osmotic stress represents a limiting physical parameter for marine organisms and especially for sessile scleractinian corals which are known to be basically stenohaline and osmoconformers. The salinity changes may cause important cellular damage since corals lack any developed physiological regulatory system. One mechanism of reaction to deleterious conditions is the rapid increase of the induction of heat shock proteins. This study highlights the modulation of the expression of a mitochondrial heat shock protein, such as the chaperonin Hsp60, in the animal tissues of the scleractinian coral Seriatopora caliendrum under three salinity scenarios (hypersalinity of 45 ppt, hyposalinity of 25 ppt and extreme hyposalinity of 15 ppt). The study was performed during the time course of a 2-day period and accompanied also by the assessment of the coral health condition. For each salinity stress S. caliendrum responds differently at the morphological and cellular levels, since the Hsp60 exhibited specific patterns of expression and the coral showed different tissue appearance. Furthermore, the response reflects the severity and exposure length of the disturbance. However, the results indicate that S. caliendrum seems able to tolerates high salinity better than low salinity. In particular, in extreme hyposalinity conditions, a considerable gradual down-regulation of Hsp60 was detected accompanied by necrosis and degradation of the coral tissues. The study suggests that Hsp60 may be involved in the mechanisms of cellular response to stress caused by exposure to adverse salinity. 相似文献