海水养虾池浮游动物对浮游植物牧食力的研究

利用常规显微镜直接计数法评估了海水养虾池浮游动物对浮游藻类的牧食力。测得虾池浮游动物对水柱浮游植物的总滤水率为８０．３８ｍｌ／（Ｌ·ｈ）,每个浮游动物的滤水率平均为１１．１３μｌ／（ｉｎｄ·ｈ）,总牧食率为１０．５０μｇ／（Ｌ·ｈ）,即１．２５ｎｇＣ／（ｉｎｄ·ｈ）。浮游动物对水柱原位主要浮游藻类的选食,以隐藻和舟形藻为最多,其次是扁藻和小环藻,６ｈ内对上述４种藻类的选食率分别为９２．６８％、７２．４６％、３６．２２％和３２．５６％,其相应的选择指数依次为０．７３３１、０．６７１７、０．４３４５和０．３９１３。对水柱总体而言,６ｈ内有３５．７２％的主要浮游藻类被选食了。     

THE ELEMENTAL COMPOSITION OF SOME MARINE PHYTOPLANKTON1

We analyzed the cellular content of C, N, P, S, K, Mg, Ca, Sr, Fe, Mn, Zn, Cu, Co, Cd, and Mo in 15 marine eukaryotic phytoplankton species in culture representing the major marine phyla. All the organisms were grown under identical culture conditions, in a medium designed to allow rapid growth while minimizing precipitation of iron hydroxide. The cellular concentrations of all metals, phosphorus, and sulfur were determined by high‐resolution inductively coupled plasma mass spectrometry (HR‐ICPMS) and those of carbon and nitrogen by a carbon hydrogen nitrogen analyzer. Accuracy of the HR‐ICPMS method was validated by comparison with data obtained with ⁵⁵Fe radioactive tracer and by a planktonic reference material. The cellular quotas (normalized to P) of trace metals and major cations in the biomass varied by a factor of about 20 among species (except for Cd, which varied over two orders of magnitude) compared with factors of 5 to 10 for major nutrients. Green algae had generally higher C, N, Fe, Zn, and Cu quotas and lower S, K, Ca, Sr, Mn, Co, and Cd quotas than coccolithophores and diatoms. Co and Cd quotas were also lower in diatoms than in coccolithophores. Although trace element quotas are influenced by a variety of growth conditions, a comparison of our results with published data suggests that the measured compositions reflect chiefly the intrinsic (i.e. genetically encoded) trace element physiology of the individual species. Published field data on the composition of the planktonic biomass fall within the range of laboratory values and are generally close to the approximate extended Redfield formula given by the average stoichiometry of our model species (excluding the hard parts): While clearly this elemental stoichiometry varies between species and, potentially, in response to changes in the chemistry of seawater, it provides a basis for examining how phytoplankton influence the relative distributions of the ensemble of major and trace elements in the ocean.     

海绵生理活性物质研究新进展

本文综述了近三年来从海绵中得到的萜类、生物碱、甾醇、肽类等具有抗菌、抗病毒、抗肿瘤、抗爱滋病及心血管活性等生理活性的物质。     

ECOTOXICOLOGICAL PERSPECTIVES IN MARINE MAMMALOGY: RESEARCH PRINCIPLES AND GOALS FOR A CONSERVATION POLICY1

In integrating ecotoxicology and marine mammalogy two principal themes are conceivable: (1) the impact of contaminants on marine mammals and (2) the feasibility of monitoring marine pollution with marine mammals. Monitoring should be an alert procedure, carried out with a sensitive sensor. Uncertainties in interpreting analyses and the low susceptibility of marine mammals to short-term changes in pollution, make them inappropriate for pollution monitoring at present. To answer the question whether pollutants affect marine mammals, the occurrence of contaminants and the response of the animals to those chemicals have to be assessed. In studying the occurrence of contaminants it is essential that atmospheric and riverine input, geochemical processes, and processes involved with the occurrence of natural compounds are considered. To investigate the mechanisms by which pollutants affect physiological processes the kinetics of contaminants in the animals and their clinical toxicity effects have to be studied. Comparative reference data on physical and chemical blood parameters facilitates checking for hematological disorders, electrolyte imbalance, serum biochemistry and hormonal changes. Following such a concept the retrospective study of pollution effects on marine mammals might be turned into a predictive approach.     

IN VITRO ANTIOXIDANT ACTIVITIES OF THE FERMENTED MARINE MICROALGA PAVLOVA LUTHERI (HAPTOPHYTA) WITH THE YEAST HANSENULA POLYMORPHA1

Microalgae are major primary producers of organic matter in aquatic environments through their photosynthetic activities. Fermented microalga (Pavlova lutheri Butcher) preparation (FMP) is the product of yeast fermentation by Hansenula polymorpha. It was tested for the antioxidant activities including lipid peroxidation inhibitory activity, free‐radical‐scavenging activity, inhibition of reactive oxygen species (ROS) on mouse macrophages (RAW264.7 cell), and inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL60). FMP exhibited the highest antioxidant activity on free‐radical scavenging, inhibitory intracellular ROS, and inhibited MPO activity. MTT [3‐(4,5‐dimethyl‐2‐yl)‐2,5‐diphenyltetrazolium bromide] assay showed no cytotoxicity in mouse macrophages (RAW264.7 cell), human myeloid cells (HL60), and human fetal lung fibroblast cell line (MRC‐5). Furthermore, the antioxidative mechanism of FMP was evaluated by protein expression levels of antioxidant enzyme (superoxide dismutase [SOD] and glutathione [GSH]) using Western blot. The results obtained in the present study indicated that FMP is a potential source of natural antioxidant.     

SYMPATRIC SEA SHELLS ALONG THE SEA'S SHORE: THE GEOGRAPHY OF SPECIATION IN THE MARINE GASTROPOD TEGULA

Uncertainty and controversy surround the geographical and ecological circumstances that create genetic differences between populations that eventually lead to reproductive isolation. Two aspects of marine organisms further complicate this situation: (1) many species possess planktonic larvae capable of great dispersal; and (2) obvious barriers to movement between populations are rare. Past studies of speciation in the sea have focussed on identifying the effects of past land barriers and on biogeographical breakpoints. However, assessing the role such undeniable barriers actually play in the initial divergence leading to reproductive isolation requires phylogenetic studies of recent radiations living in varying degrees of sympatry and allopatry to see which barriers (if any) tend to separate sister species. Here I infer phylogenetic relationship between 23 species of the marine snail Tegula using DNA sequences from two regions of the mitochondrial genome: cytochrome c oxidase I (COI) and the small ribosomal subunit (12S) These snails possess planktonic larvae with moderate dispersal capabilities and have speciated rapidly with over 40 extant species arising since the genus first appeared in the mid-Miocene (about 15 M.Y.B.P.). Trees constructed from the COI and 12S regions (which yielded 205 and 137 phylogenetically informative sites, respectively) were robust with respect to tree-building method, bootstrapping, and the relative weightings of transitions, transversions, and gaps Within clades where all extant species have been sampled, five of six identified sister species pairs broadly coexist on the same side of biogeographical boundaries. These data suggest strong geographical barriers to gene flow may not always be required for speciation in the sea; transient allopatry or even ecological barriers may suffice. A survey of the geographic distributions of marine radiations suggests that coastal distributions may favor the sympatry of sister taxa more than island distributions do.     

昆虫细胞分类学的基本问题及染色体系统发育的重建方法

本文非昆虫细胞遗传学及细胞分类学原理与技术的全面评述;而是从细胞遗传学特征（或称染色体特征）在混虫分类学中的应用入手,重点提出与分析了昆虫细胞分类学中的种类鉴定,研究取材,染色体多态现象,多倍体及核型进化方向等基本问题,并着重总结了目前国际上细胞水平染色体数据的处理方法,即传统法,倒位法,数值法与支序法;最后,作者指出了正确看待细胞分类学重要性的态度。     

台湾海峡鱼类绦虫的分子系统学研究

利用DNA测序技术对台湾海峡部分鱼类绦虫的16S rRNA和18S rRNA基因片段序列进行了分析。使用PAUP4·0b10软件构建的进化树显示,目前关于绦虫二叶目、锥吻目、假叶目、盘头目和四叶目的划分是比较合理的,绦虫进化基本遵循了头节形态从简单到复杂的进化规律。报道了国内首次发现的双叶目绦虫,进化树结果初步支持了巨槽属和棘头属的划分。此外,结果也支持了前孔属绦虫的分类地位。但是,对耳槽属绦虫与阶室属绦虫的形态学划分与分子系统学相矛盾,利用16S rRNA基因对盘头目各种的进化树分析与形态学差异很大,这些问题都需要更多研究来进行深入分析。     

THE PLASMA PROTEINS OF SOME FRESHWATER FISH IN THEIR NATURAL ENVIRONMENT

SUMMARY

The plasma proteins of Cyprinus carpio (carp), Barbus holubi (yellowfish), Labeo umbratus (mudfish) and Labeo capensis (mudfish) were electrophoretically separated on polyacrylamide gels from blood samples obtained from specimens sampled during summer and winter in three different localities. Within a species, differences existed in the summer and winter plasma protein electrophoretograms from the different localities. During winter protein fraction concentration differences were found with a displacement of prominence. The results are compared between different experimental conditions and to previous observations. A genetic trait is present, but there were also alterations as a result of environmental factors.     

我国南方旧石器时代晚期文化的若干问题

本文对我国南方已发现的旧石器时代晚期的文化资料作一简要总结,并对其中的若干问题作了初步的探讨。     

THE EFFECTS OF CONTRASTING MODES OF FERTILIZATION ON LEVELS OF INBREEDING IN THE MARINE INVERTEBRATE GENUS CORELLA

A simple difference in the body design of two species of marine urochordates in the ascidian genus Corella suggested that these species may differ in their mating systems. The two coexisting species share common life-history traits and morphology with the exception of a difference in body design that affects site of fertilization and embryonic development. Corella inflata has internal fertilization and embryonic development, while C. willmeriana has external fertilization and embryonic development. The natural mating system of these two species of solitary ascidians was inferred by comparing the relative survival of selfed and outcrossed fertilizations in the laboratory. Corella inflata, the internal fertilizer, showed no difference in survival between selfed and outcrossed fertilizations at any developmental stage through metamorphosis and early juvenile development. In contrast, self-fertilized crosses of C. willmeriana had significantly lower survival than outcrossed fertilizations even at the earliest scorable developmental stages. These results suggest that C. inflata may inbreed frequently in nature, while viable C. willmeriana offspring are primarily a result of outcrossing. The internally-fertilizing species, C. inflata, showed approximately 10% male sterility in laboratory crosses despite apparent morphological hermaphroditism. The externally-fertilizing, commonly outcrossing species, C. willmeriana, showed no difference in fertility between genders.     

DIEL OSCILLATIONS IN THE PHOTOSYNTHESIS-IRRADIANCE RELATIONSHIP OF A PLANKTONIC MARINE DIATOM1

The amplitude of diel oscillations in photosynthesis as a function of irradiance varied with the growth phase in a marine phytoplankton species. The common centric diatom (Bacillariophyta), Ditylum brightwellii (West) Grun., showed strong periodicity in the photosynthesis-irradiance (P-I) relationship, which damped progressively from early to late exponential and stationary phase. These findings suggest that short-term temporal characteristics of phytoplankton production depend on factors which affect growth, and that the amplitude is most enhanced at maximal growth rates likely to be encountered in the natural environment.     

竹亚科分类的若干方法问题—兼论牡竹属的范畴

中国竹亚科分类自70年代末以来取得了长足进展,但在高山竹类的属名、种类处理,青篱竹属在中国是否存在,以及丛生竹的属级界线等问题上,国内学者间,以及国内学者与国外学者间存在不同意见。读了林万涛关于中国牡竹属的两篇文章后,认为有必要就牡竹属的范畴作一讨论,其中也涉及国内竹亚科分类的若干方法论问题。根据分支系统学的原理,“广义牡竹属”是一个单系类群。参照Clayton对属级分类阶元提出的几条原则,特别是性状的选择,讨论了椅于竹属与碟环慈竹属的归属问题。笔者认为,数量分类学并不探讨类群的起源问题,研究系统发育则需要多学科的证据,因而单从营养体个别性状的相似性来推测系统发育是不可取的。最后本文归并了椅子竹属和碟环慈竹属。     

THE DISTRIBUTION AND ECOLOGY OF TWO MULLET SPECIES IN SOME FRESH WATER RIVERS IN THE EASTERN CAPE,SOUTH AFRICA

SUMMARY

Data on the relative abundance, penetration and breeding biology of the freshwater mullet Mugil cephalus and the flathead mullet Mugil cephalus in the freshwater reaches of some Eastern Cape coastal rivers are described. The differences found between the two species indicate that Myxus capensis is more specialized for a catadromous life history in an unstable riverine environment. Evidence showing the importance of the freshwater phase for the latter species is given and the disastrous effects of the erection of barriers to fish movement are stressed.     

FEEDING ECOLOGY OF THE MARINE OTTER (LUTRA FELINA) IN A ROCKY SEASHORE OF THE SOUTH OF CHILE

The marine otter ( Lutra felina ) lives exclusively along exposed rocky shorelines on the South American Pacific coast from Peru (6°S), to Cape Horn, Chile (56°S), and Isla de los Estados, Argentina. L. felina diet and its relationship to prey availability and energy content was assessed by spraint and prey remains analysis, direct observation, and the use of crab pots and fish traps, at four sites on the Valdivian coast in the south of Chile, between June 1999 and June 2000. Based on spraints analysis, the diet was composed of 25 species; 52% (13/25) of the species identified were crustaceans, 40% (10/25) were fish, and 8% (2/25) were mollusks. Crustaceans were found in 78% of 475 spraints, 100% of 929 prey remains, and 90.8% of prey determined by direct observation, fish in 20% of spraints and 9.0% of prey determined by direct observation, and mollusks in 2% of spraints and 0.2% of prey determined by direct observation. Observed seasonal variation in prey availability was reflected in the otter diet. Fourteen prey species were trapped; 43% (6/14) were crustaceans and 57% (8/14) fish, crustaceans were 93% of 566 trapped individuals, fish 7%. L. felina showed opportunistic feeding behavior, selecting prey seasonally according to their availability rather than to their energy input.