Light-Dependency of Growth and Secondary Metabolite Production in the Captive Zooxanthellate Soft Coral Sinularia flexibilis

The branching zooxanthellate soft coral Sinularia flexibillis releases antimicrobial and toxic compounds with potential pharmaceutical importance. As photosynthesis by the symbiotic algae is vital to the host, the light-dependency of the coral, including its specific growth rate (µ day-1) and the physiological response to a range of light intensities (10–1,000 µmol quanta m-2 s-1) was studied for 12 weeks. Although a range of irradiances from 100 to 400 µmol quanta m-2 s-1 was favorable for S. flexibilis, based on chlorophyll content, a light intensity around 100 µmol quanta m-2 s-1 was found to be optimal. The contents of both zooxanthellae and chlorophyll a were highest at 100 µmol quanta m-2 s-1. The specific budding rate showed almost the same pattern as the specific growth rate. The concentration of the terpene flexibilide, produced by this species, increased at high light intensities (200–600 µmol quanta m-2 s-1)

Effects of reduced dissolved oxygen concentrations on physiology and fluorescence of hermatypic corals and benthic algae.

While shifts from coral to seaweed dominance have become increasingly common on coral reefs and factors triggering these shifts successively identified, the primary mechanisms involved in coral-algae interactions remain unclear. Amongst various potential mechanisms, algal exudates can mediate increases in microbial activity, leading to localized hypoxic conditions which may cause coral mortality in the direct vicinity. Most of the processes likely causing such algal exudate induced coral mortality have been quantified (e.g., labile organic matter release, increased microbial metabolism, decreased dissolved oxygen availability), yet little is known about how reduced dissolved oxygen concentrations affect competitive dynamics between seaweeds and corals. The goals of this study were to investigate the effects of different levels of oxygen including hypoxic conditions on a common hermatypic coral Acropora yongei and the common green alga Bryopsis pennata. Specifically, we examined how photosynthetic oxygen production, dark and daylight adapted quantum yield, intensity and anatomical distribution of the coral innate fluorescence, and visual estimates of health varied with differing background oxygen conditions. Our results showed that the algae were significantly more tolerant to extremely low oxygen concentrations (2-4 mg L(-1)) than corals. Furthermore corals could tolerate reduced oxygen concentrations, but only until a given threshold determined by a combination of exposure time and concentration. Exceeding this threshold led to rapid loss of coral tissue and mortality. This study concludes that hypoxia may indeed play a significant role, or in some cases may even be the main cause, for coral tissue loss during coral-algae interaction processes

Five new coexisting species of copepod crustaceans of the genus Spaniomolgus (Poecilostomatoida: Rhynchomolgidae), symbionts of the stony coral Stylophorapistillata (Scleractinia)

Spaniomolgus is a symbiotic genus of copepods of the poecilostomatoid family Rhynchomolgidae and is known to be associated with shallow-water reef-building hermatypic corals. Three species of this genus were previously found only in washings of Acropora and Stylophora in northern Madagascar. Four coral morphotypes of Stylophorapistillata (Pocilloporidae) were collected by SCUBA at 1 to 28 m depth in five sites in the Saudi Arabian Red Sea in 2013. Copepods found on these colonies were studied using light, confocal and scanning electron microscopy. Five new, and one known, species of the genus Spaniomolgus were discovered in washings and inside the galls of the hermatypic coral S.pistillata. The description of these new species (Spaniomolgusglobussp. n., S.stylophorussp. n., S.dentatussp. n., S.maculatussp. n., and S.acutussp. n.) and a key for the identification of all of its congeners is provided herein

The Copper and Reduced Salinity Effects on Metabolism of Hermatypic Coral Fungia SP

The research determined the physiological responses in Fungia sp that's exposed to combination of copper presence and reduced salinit for 12 h. The changes of primary production rate per chlorophyll-a and respiration per surface area were used to determine the stress occur. The results showed that no significant on the respiration rate in any of treatments between treatments or compared with control. Corals exposed to 10 µg.l-1 copper to reduced salinity were unaffected and did not affect the production rate. Coppers exposed to 30 µg.l-1 copper, reduced salinity, and combination of two stressors significantly decreased the production rate of Fungia sp

Preliminary Studies on Light Adaptation and Response to Ca2+ and pH Changes in Shallow-water Corals

珊瑚礁生态系统拥有很高的初级生产力和生物多样性，是一类具有重要的生态功能且极为特殊的生态系统。同时，珊瑚色彩绚丽，种类多样，也具有极高的观赏价值与经济价值，在水族宠物市场备受关注。由于野外采集珊瑚的不可持续性以及对珊瑚礁生态系统的潜在破坏，目前，国内外越来越多的研究开始关注珊瑚尤其是造礁珊瑚人工养殖的环境影响因素。本文研究了不同珊瑚的光适应性，以及钙离子浓度、pH两个重要环境因子对珊瑚的影响，以便有针对性的优化珊瑚养殖系统，提高珊瑚人工养殖的效率。主要研究内容和结果如下： 1、使用调制叶绿素荧光仪（Pulse-Amplitude-Modulation）对18种常见养殖珊瑚的叶绿素荧光参数（F...Coral reef ecosystem is a type of extremely unique ecosystem in the world, with significant primary productivity, biodiversity and important ecology function. Meanwhile, corals are well known for its gorgeous color and abundant species, so corals are highly concerned in the international ornamental market. Because of the unsustainable of wild collection and potential destruction to the coral reef ...学位：理学硕士院系专业：环境与生态学院_环境科学学号：3312012115164

Evolutionary responses of marine invertebrates to insular isolation in Galapagos

I examine the natural barriers to distribution and colonization that have shaped the Galapagos marine invertebrate biota. While diversity is high for some groups, such as hydroids and bryozoans, it is low for many others. Porcelain crabs and molluscs are examples with reduced or unbalanced representation in Galapagos, resulting from their dependency on dispersal of relatively short-lived planktonic larvae by ocean currents and on habitat limitations in Galapagos. Because Galapagos shorelines are predominantly rocky, without the wide expanses of silt typical of much of the Ecuadorian mainland that are favored by infaunal bivalves, gastropod diversity in Galapagos far exceeds that of bivalves. Nearly all hermatypic corals in Galapagos are members of the Panamic province; none is endemic to Galapagos. This suggests that colonization occurred by larval dispersal from there. The ahermatypic (azooxanthellate) coral fauna of Galapagos, with 43 species, is richer and more diverse than the hermatypic corals, with 29% of the shallow-water ahermatypes endemic and the remainder with Panamic, Indo-Pacific, and cosmopolitan affinities. The 73 verified species of Galapagos shallow-water echinoderms are dominated by Panamic species, with additional affinities to the Indo-Pacific and the California province; 8% are cosmopolitan and 8% endemic. With species richness roughly equivalent to that of Pacific Colombia, Galapagos echinoderm representation is not depauperate, but is sufficiently distinctive to characterize it as an isolated, insular biota. Hydroids and bryozoans, two groups with high diversity in Galapagos, accomplish long-distance transport mainly as adults on floating debris and hulls of ships, rather than by the free-swimming reproductive stage. Endemism among marine invertebrates averages 18.3 %, but varies widely among major taxa, from 0% for reef corals to 71% for gorgonians. Unlike the Galapagos terrestrial biota, in which endemic genera are common, the absence of endemic genera among marine invertebrates may be attributed to low isolation arising from greater dispersal and gene flow in the marine environment