Do microbes have macroecology? Large‐scale patterns in the diversity and distribution of marine benthic ciliates

Aim The biogeography and global distribution of protists has long been disputed, with two primary, opposing views. To test these two sets of views in greater detail, we have compiled the available data for marine benthic ciliates and assessed the general patterns of their diversity and distribution compared with Metazoa. Location World‐wide. Methods A comprehensive database (1342 species, over 350 sources) was used to analyse the diversity, distribution, species occurrences and range size distribution of free‐living ciliates that inhabit marine sediments in 17 geographical regions. Results Twenty‐five per cent of the species have been found in a single region only, whereas 18% are widespread (they occur in more than half the regions covering both hemispheres). Only 5–7% of regional faunas are endemic, which is much lower than for macroorganisms. Regional diversity depends neither on total area nor on coastline length and does not show any obvious latitudinal trends, but correlates highly with the investigation effort expended in a region and (negatively) with the average salinity. A comparison of species composition reveals distinctions between the Arctic Area (the White, Barents and Kara seas), Laurasian Area (north Atlantic, north Pacific and European seas), Gondwanian Area (Southern Ocean) and the Antarctic. No clear geographical correlations are found for faunistic composition at the genus or family levels. There is the tendency to narrow the latitudinal ranges for species found at high latitudes (reversal of Rapoport's rule). Main conclusions Undersampling and data insufficiency are the key factors affecting the observed diversity and distribution of microorganisms. Nevertheless, marine benthic ciliates demonstrate certain patterns that generally agree with the ‘moderate endemicity’ model ( Foissner, 2004, 2008 ), but consistently contradict the regularities commonly observed for multicellular taxa. Thus, ciliates do have a biogeography, but their macroecological patterns may be different in some respects from that of macroorganisms.     

Determining Allocation: From Paper to Practice in the Distribution of Fishing Rights Between Countries

This article discusses the allocation problem in international fisheries management, which is critical to effective resource management. A number of cases where allocation problems exist are reviewed and trends identified. It is concluded that power relationships between the states involved are an important determinant of allocation outcomes. While this may seem a frustrating conclusion, it nevertheless reflects the realities of international cooperation.     

The reproductive phenology of nine species of Rhodophyta in the subtidal region of the Isle of Man

Monthly samples of about 40 separate plants of each species were collected from 1 to 3 m below lowest astronomical tide on Port Erin breakwater, Isle of Man, Irish Sea. In three species growing on rock, Plocamium cartilagineum, Cryptopleura ramosa and Callophyllis laciniata, about 90% of the plants were fertile in late summer but less than 10% in spring although some fertile plants were always present. Delesseria sanguinea and Odonthalia dentata, also epilithic, had a winter sporing season, Odonthalia extending into late spring, and all plants were sterile in summer. Three species growing epiphytically, Palmaria palmata, Membranoptera alata and Phycodrys rubens, reproduced maximally in the first half of the year at the time when the stipes of the host species, Laminaria hyperborea, grow fastest. Only Palmaria had a sterile season, late summer. The encrusting Cruoria pellita showed little seasonality. The first three species, which reproduce mainly when the sea temperature is above average, are in the northern part of their geographical range. The remaining species (apart from Cruoria) reproduce mainly at low temperatures and are in the southern half of their ranges. Male plants appear to be in a minority in all species, presumably because they were manifest for a shorter period than carposporic plants. They appeared first after sterile periods and were absent as sporing declined. Plocamium and to a lesser extent Cryptopleura show an extremely high preponderance of tetrasporophytes in the population. This is attributed to perennation and some factor disallowing the survival of most of the tetraspores.     

Complete genome sequence of Desulfocapsa sulfexigens,a marine deltaproteobacterium specialized in disproportionating inorganic sulfur compounds

Desulfocapsa sulfexigens SB164P1 (DSM 10523) belongs to the deltaproteobacterial family Desulfobulbaceae and is one of two validly described members of its genus. This strain was selected for genome sequencing, because it is the first marine bacterium reported to thrive on the disproportionation of elemental sulfur, a process with a unresolved enzymatic pathway in which elemental sulfur serves both as electron donor and electron acceptor. Furthermore, in contrast to its phylogenetically closest relatives, which are dissimilatory sulfate-reducers, D. sulfexigens is unable to grow by sulfate reduction and appears metabolically specialized in growing by disproportionating elemental sulfur, sulfite or thiosulfate with CO₂ as the sole carbon source. The genome of D. sulfexigens contains the set of genes that is required for nitrogen fixation. In an acetylene assay it could be shown that the strain reduces acetylene to ethylene, which is indicative for N-fixation. The circular chromosome of D. sulfexigens SB164P1 comprises 3,986,761 bp and harbors 3,551 protein-coding genes of which 78% have a predicted function based on auto-annotation. The chromosome furthermore encodes 46 tRNA genes and 3 rRNA operons.     

我国海洋细菌新物种鉴定与资源研发进展

近年来国际上对海洋微生物资源的发掘方兴未艾。本文综述了2000年以来我国在海洋细菌新物种鉴定与资源研发方面的进展,统计分析了国内相关单位海洋细菌新物种鉴定发表的数量及多样性,介绍了国内相关科研机构在海洋细菌系统学方面的工作进展,以及国内海洋微生物资源保藏与开发现状。比较了世界范围内海洋细菌系统学研究进展,并探讨了海洋细菌分离培养的主要方法,最后小结了我国海洋细菌资源研究领域存在的问题及未来发展的前景,为其进一步研发利用提供参考。     

Liquid-Saturated Hydrocarbons Resulting from Pyrolysis of the Marine Coccolithophores Emiliania huxleyi and Gephyrocapsa oceanica

Two nanoplanktonic marine coccolithophores, Emiliania huxleyi and Gephyrocapsa oceanica, were grown at 23°C with a 16-hour light and 8-hour darkness regimen. The cells were dried at room temperature and then subjected to pyrolysis at 100° to 500°C under anoxygenic conditions to produce hydrocarbons. Temperature-dependent profiles of the liquid-saturated hydrocarbons (saturates) produced during pyrolysis were very similar for the two strains, although the total amount was higher in E. huxleyi than in G. oceanica. The amount of saturates produced was only 0.05% to 0.15% below 200°C, but about 2.1% to 2.8% at 300°C. Their major components were normal alkanes in a series ranging from nC₁₁ to nC₃₅ with the predominant peak at nC₁₅. At 400° and 500°C most of saturates transformed into gaseous compounds. The major saturates identified in all pyrolysates were normal C₃₁ monounsaturated and diunsaturated alkenes, a series of normal alkanes, phytenes, C₂₈ sterenes, and steranes. Profiles of saturates in gas chromatography–mass spectroscopy varied with increasing pyrolysis temperature and also differed between E. huxleyi and G. oceanica. The two coccolithophores are useful candidates for the production of renewable liquid fuel through pyrolysis—especially E. huxleyi, which has higher production. The results also provide information for further studies on the characterization, source, and paleogeographic distribution of marine sediment. Received October 28, 1998; accepted February 15, 1999     

Antifungal activity of some marine organisms from India,against food spoilage Aspergillus strains

Crude aqueous methanol extracts obtained from 31 species of various marine organisms (including flora land faunal), were screened for their antifungal activity against food poisoning strains of Aspergillus. Seventeen species exhibited mild (+ =zone of inhibition 1–2 mm) to significant (+++ =zone of inhibition 3–5 mm) activity against one or the other strain under experiment. However, extracts of 12 species were active against all the three strains. Organisms like Salicornia brachiata(obligate halophyte), Sinularia leptocladus(Soft coral), Elysia grandifolia (Mollusks),Gorgonian sp. 2 and Haliclona sp. exhibited significant (inhibition zone of 3–5 mm) antifungal activity against one or the other strains. However,extracts of A. ilicifolius, Amphiroa sp.,Poryphyra sp., Unidentified sponge, Suberites vestigium, Sinularia compressa,Sunularia sp., Sinularia maxima, Subergorgia suberosa, Echinogorgia pseudorassopo and Sabellaria cementifera were mild (inhibition zone of 1–2 mm) to moderate(inhibition zone of 2–3 mm) active against the respective strains. The growth of A. japonicuswas significantly inhibited by the extracts ofS. leptocladus (r = 0.992, p < 0.0001)and E. grandifolia (r = 0.989, p < 0.0001).This revised version was published online in October 2005 with corrections to the Cover Date.     

Computer vision-assisted photogrammetry and one-image 3D modeling in marine mammals

Image processing using traditional photogrammetric methods is a labor-intensive process. The collection of photogrammetry images during aerial surveys is expanding rapidly, creating new challenges to analyze images promptly and efficiently, while reducing human error during processing. Computer vision-assisted photogrammetry, a field of artificial intelligence (AI), can automate image processing, greatly enhancing the efficiency of photogrammetry. Here, we present a practical and efficient program capable of automatically extracting the fine-scale photogrammetry of East Asian finless porpoises (Neophocaena asiaeorientalis sunameri). Our results indicated that computer vision-assisted photogrammetry could achieve the same accuracy as traditional photogrammetry, and the results of the comparisons were validated against the direct measurements. Three-dimensional (3D) models using computer vision-assisted photogrammetric morphometrics generated trustworthy body volume estimates. We also explored the one image-based 3D modeling technique, which is less accurate, but still useful when only one image of the animal is available. Although several limitations exist in the current program, improvements could be made to narrow the virtual-reality gap when more images are available for machine learning and training. We recommend this program for analyzing images of marine mammals possessing a similar morphological contour.     

Sodiumd-glucose cotransport in the gill of marine mussels: Studies with intact tissue and brush-border membrane vesicles

Summary Glucose transport was studied in marine mussels of the genusMytilus. Initial observations, with intact animals and isolated gills, indicated that net uptake of glucose occurred in mussels by a carrier-mediated, Na⁺-sensitive process. Subsequent studies included use of brush-border membrane vesicles (BBMV) in order to characterize this transport in greater detail. The highest activity of Na⁺-dependent glucose transport was found in the brush-border membrane fractions used in this study, while basal-lateral membrane fractions contained the highest specific binding of ouabain. Glucose uptake into BBMV showed specificity for Na⁺, and concentrative glucose transport was observed in the presence of an inwardly directed Na⁺ gradient. There was a single saturable pathway for glucose uptake, with an apparentK _t of 3 m in BBMV and 9 m in intact gills. The kinetics of Na⁺ activation of glucose uptake were sigmoidal, with apparent Hill coefficients of 1.5 in BBMV and 1.2 in isolated gills, indicating that more than one Na⁺ may be involved in the transport of each glucose. Harmaline inhibited glucose transport in mussel BBMV with aK _i of 44 m. The uptake of glucose was electrogenic and stimulated by an inside-negative membrane potential. The substrate specificity in intact gills and BBMV resembled that of Na⁺-glucose cotransporters in other systems;d-glucose and -methyl glucopyranoside were the most effective inhibitors of Na⁺-glucose transport,d-galactose was intermediate in its inhibition, and there was little or no effect ofl-glucose,d-fructose, 2-deoxy-glucose, or 3-O-methyl glucose. Phlorizin was an effective inhibitor of Na⁺-glucose uptake, with an apparentK _i of 154nm in BBMV and 21nm in intact gills. While the qualitative characteristics of glucose transport in the mussel gill were similar to those in other epithelia, the quantitative characteristics of this process reflect adaptation to the seawater environment of this animal.