单壁碳纳米管对太平洋牡蛎(Crassostrea gigas)的毒性效应及生物体防御机制研究

碳纳米管的生态安全和健康风险日益受到人们的广泛关注。本文采用典型的海洋底栖生物——太平洋牡蛎(Crassostrea gigas, C. gigas)作为受试生物,研究了单壁碳纳米管(Single-Walled Carbon Nanotubes, SWCNTs)暴露对其造成的毒性效应及牡蛎自身的防御机制,以期为碳纳米管的海洋生态风险评价提供科学依据。在0.1～10 mg·L~(-1)的SWCNTs暴露96 h后,太平洋牡蛎鳃和消化腺中的丙二醛(malondialdehyde, MDA)含量显著增加(P≤0.05),总超氧化物歧化酶(superoxide dismutase, SOD)和过氧化氢酶(catalase, CAT)活性呈现显著的剂量依赖性升高(P≤0.05),cat、hsp70、aox及caspase-7等基因的相对表达量显著上调(P≤0.05)。相比于单独暴露,P-gp蛋白抑制剂Tariquidar与SWCNTs的复合暴露显著增加了鳃和消化腺中MDA含量,产生了更严重的氧化损伤。这些结果表明,SWCNTs暴露对太平洋牡蛎的鳃和消化腺造成了一定程度的氧化损伤,而牡蛎体内的抗氧化系统和多外源性物质抗性机制在防御SWCNTs的过程中起到了至关重要的作用。     

Importance of jumbo squid Dosidicus gigas (Orbigny, 1835) in the pelagic ecosystem of the central Gulf of California

The Humboldt squid is an important predator in the pelagic ecosystem of the central Gulf of California and the commercial catch of this species has increased over the past decade, probable due to a decrease of several top predators (sharks, large pelagic fish and the marine mammals) and the optimal feeding conditions in this area. Its high abundance and important position in the pelagic food web was quantified through two trophic models of the pelagic ecosystem of the central Gulf of California. Models represented conditions in 1980 and 2002, to document the decadal changes in ecosystem structure and function. The models were composed of 18 functional groups, including marine mammals, birds, fish, mollusks, crustaceans, and primary producers. Model results show direct negative effects on principal prey groups such as myctophids and pelagic red crab and positive effects on sharks, marine mammals and specifically sperm whales. It thus appears that the jumbo squid has an important role in the ecosystem and plays a central part in the overall energy flow as main food item for most top predators, and due to its predation of organisms on lower tropic levels.     

Predatory behavior of crowned hawk-eagles (Stephanoaetus coronatus) in Kibale National Park, Uganda

Evaluating the nature and significance of predation on populations of wild primates has been difficult given a paucity of data regarding the phenomenon. Here we addressed this problem in a 37-month study of the predatory behavior of crowned hawk-eagles living at the Ngogo study site in Kibale National Park, Uganda. We collected prey remains underneath the nests of two pairs of eagles and census data on potential prey species to investigate prey selection and the ecological impact of predation on the Ngogo primate population. Results indicate that primates form the vast majority of all prey items. Eagles prey selectively on monkeys according to sex and species. Male primates were taken more often than females, while two species, redtail monkeys and mangabeys, were captured significantly more and less, respectively, than chance expectation. In addition, there was no bias in the age of prey: adult and non-adults were killed in numbers roughly equal to their proportional representations in the forest. Further analyses indicate that a non-trivial fraction of the entire primate population at Ngogo succumbs to crowned hawk-eagle predation each year. These results reveal both parallels and contrasts with those reported previously. Some of the parallels are due to similarities in prey availability, while contrasts are likely related to methodological differences between studies, inter- individual variations in predator hunting styles, and differences in prey abundance, demography, and behavior. Received: 29 March 2000 / Revised: 6 June 2000 / Accepted: 15 October 2000     

Lethal effects of Northwest Atlantic Ocean isolates of the dinoflagellate, Scrippsiella trochoidea, on Eastern oyster (Crassostrea virginica) and Northern quahog (Mercenaria mercenaria) larvae

The thecate dinoflagellate Scrippsiella trochoidea is a cosmopolitan, bloom-forming alga that has been generally considered non-toxic. Here, we report that environmentally relevant cell densities (10⁴ cells mL⁻¹) of Scrippsiella trochoidea strains isolated from the Northwest Atlantic Ocean caused 100% mortality in Eastern oyster (Crassostrea virginica) larvae during 3-day exposures while parallel control larvae exhibited 100% survival. S. trochoidea also exhibited lethal effects on Northern quahog (Mercenaria mercenaria) larvae (70% mortality during 3-day exposure) but were non-toxic to juvenile fish (Cyprinodon variegates). The cultures of S. trochoidea were more lethal to Northern quahog larvae than ten other species of harmful algae, including the highly toxic species Cochlodinium polykrikoides. Scrippsiella trochoidea cultures within later stages of growth were more toxic than exponential growth stages to bivalve larvae, and the toxicity was dose dependent. Furthermore, toxicity was maintained in the cultures that were sonicated, boiled, and frozen as well as in resuspended residues of the culture but was significantly lower in cell-free culture media. Collectively, these results suggest that S. trochoidea causes mortality in bivalve larvae through a physicochemical rather than strictly chemical mechanism, such as clogging of larval feeding apparatuses by materials produced by S. trochoidea (e.g., lipids, extracellular polysaccharides, and/or cell debris) which accumulate as cells in culture or blooms age. This is the first report of the lethal effects of Scrippsiella trochoidea on shellfish larvae.     

环丙沙星(CIP)对鲤鱼早期生长阶段的影响

我们依据经济合作与发展组织的210指导性文件,利用鲤鱼受精卵,进行环丙沙星(CIP)的毒性试验。测试浓度设置为1、100、500、1 000和3 000 μg?L^L-1。我们发现在所有测试组中,暴露于CIP会加速孵化,但在暴露于最高浓度CIP(3000 μg?L^L-1)的测试组,出现了显著的生长下降的现象。在实验的第6天(孵化之后),可以观察到大量增加的肉眼可见的形态异常现象。最高数量肉眼可见的形态异常现象是在自由胚胎和幼虫CIP暴露浓度为100、500、1 000和3 000 μg?L^L-1的测试组中产生的(测试样本的20%~23%)。在所有CIP暴露试验组中,均检测出GST活性的呈逐步降低趋势,但是在CIP浓度为500和3 000 μg?L^L-1的测试组中出现了显著差异(p < 0.01)。其中在大多数测试浓度下,谷胱甘肽过氧化物酶和过氧化氢酶的活性增加(p < 0.01,p < 0.05),而在CIP暴露浓度为500和3 000 μg?L^L-1的测试组,谷胱甘肽还原酶出现活性降低的现象(p < 0.05)。在所有的CIP暴露组中,硫代巴比妥酸活性物质的浓度明显降低(p < 0.01)。可测的CIP最低有效浓度(LOEC)是1 μg?L^L-1。\这些结果表明,孵化过程,早期的个体发育,形态异常的产生,以及鱼类体内的抗氧化和生物转化酶活性和脂质过氧化反应,都会受到CIP影响。
精选自Dana Zivna, Lucie Plhalova, Lucie Chromcova, Jana Blahova, Miroslav Prokes, Misa Skoric, Petr Marsalek, Eva Praskova, Stanislava Stepanova, Zdenka Svobodova. The effects of ciprofloxacin on early life stages of common carp (Cyprinus carpio). Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1733–1740, July 2016. DOI: 10.1002/etc.3317
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3317/full
     

Costs and benefits of home range shifts among vervet monkeys (Cercopithecus aethiops) in Amboseli National Park,Kenya

Summary A decline in the density of trees and the deterioration of the habitat of vervet monkeys (Cercopithecus aethiops) in Amboseli National Park, Kenya, have been accompanied by movement of vervet groups into unfamiliar areas. These home range shifts were documented over a period of 26 months. The largest group moved into the home ranges of neighboring groups and acquired more trees, a resource that had become more limited. The groups whose home ranges were encroached upon did not share their home ranges with the intruders, but instead moved into areas that were unoccupied and had a lower density of trees. The largest group was thus more successful than smaller groups in competition for limited resources. For all but one group, movement into new areas was directly associated with the disappearances of female and immature monkeys. Most of the disappearances were attributable to predation. These results suggest that the cost of predation in unfamiliar areas may contribute to the evolution of philopatry in vervets. However, under unstable conditions, resource competition forces these animals to disperse (in groups) despite the high risk of predation. Offprint requests to: L.A. Isbell     

土壤Cd污染对跳虫Folsomia candida的生态毒性

采矿及冶炼等行为造成了严重的土壤重金属污染,其中Cd污染及其带来的健康风险近年来引起人们的高度重视。利用弹尾目跳虫开展土壤Cd污染的生态毒理研究,对Cd污染土壤的生态风险评价具有重要意义。本研究将跳虫Folsomia candida(F.candida)暴露在不同Cd浓度污染的人工土壤中,利用跳虫存活数量、繁殖数量及回避行为实验来评价重金属Cd污染对跳虫的生态毒性。结果表明,Cd对F.candida的急性毒性LC50值为2 086.93 mg·kg~(-1),慢性毒性的繁殖抑制(28 d)EC50值为224.95 mg·kg~(-1)。此外,Cd对跳虫回避行为影响的EC50(48 h)为721.26 mg·kg~(-1)。可以看出,慢性毒性的EC50值与Cd对回避行为影响的EC50值近似,但远低于急性毒性LC50值。因此,跳虫F.candida的回避行为和繁殖率对Cd污染土壤有较高的灵敏度,可用来表征土壤中Cd的生态毒性。     

Using the ECLPSS software environment to build a spatially explicit component-based model of ozone effects on forest ecosystems

We have developed a modeling framework to support grid-based simulation of ecosystems at multiple spatial scales, the Ecological Component Library for Parallel Spatial Simulation (ECLPSS). ECLPSS helps ecologists to build robust spatially explicit simulations of ecological processes by providing a growing library of reusable interchangeable components and automating many modeling tasks. To build a model, a user selects components from the library, and then writes new components as needed. Some of these components represent specific ecological processes, such as how environmental factors influence the growth of individual trees. Other components provide simulation support such as reading and writing files in various formats to allow inter-operability with other software. The framework manages components and variables, the order of operations, and spatial interactions. The framework provides only simulation support; it does not include ecological functions or assumptions. This separation allows biologists to build models without becoming computer scientists, while computer scientists can improve the framework without becoming ecologists. The framework is designed to operate on multiple platforms and be used across networks via a World Wide Web-based user interface. ECLPSS is designed for use with both single processor computers for small models, and multiple processors in order to simulate large regions with complex interactions among many individuals or ecological compartments. To test Version 1.0 of ECLPSS, we created a model to evaluate the effect of tropospheric ozone on forest ecosystem dynamics. This model is a reduced-form version of two existing models: , which represents an individual tree, and , which represents forest stand growth and succession. This model demonstrates key features of ECLPSS, such as the ability to examine the effects of cell size and model structure on model predictions.     

Differences in somatic and gonadic growth of sea urchins ( Stronglyocentrotus droebachiensis ) fed kelp ( Laminaria longicruris ) or the invasive alga Codium fragile ssp. tomentosoides are related to energy acquisition

The rocky subtidal community off the Atlantic coast of Nova Scotia has historically undergone a cyclical transition between Laminaria-dominated kelp beds and sea urchin-dominated barrens. Since the introduction of the invasive alga Codium fragile ssp. tomentosoides, a third community state has emerged: Codium-dominated algal beds. We conducted a 42-week feeding experiment in the laboratory, which mimicked the quantity and quality of food available to urchins (Strongylocentrotus droebachiensis) in each of these community states. Feeding rate, growth, reproduction, and survival of urchins fed either Laminaria longicruris or C. fragile ad libidum, or L. longicruris 2 days per month, were measured. Although the ad libidum feeding rate on C. fragile was higher than that on kelp, energy intake was lower. Urchins in the ad libidum kelp treatment were larger and had larger gonads than those in the C. fragile treatment. Urchins fed kelp infrequently exhibited little somatic and gonadic growth over the course of the experiment. Regression analysis revealed that urchin performance on these diets was strongly related to energy intake. Diet treatment had no effect on survival or gonad maturation. Although urchins can consume substantial amounts of C. fragile, it appears that they cannot, or do not, feed quickly enough to compensate for its lower nutritional value. Our results suggest that, although urchins feeding on C. fragile are capable of surviving, growing, and reproducing, the replacement of kelp by C. fragile in some areas might negatively affect urchin populations as they continue to repopulate the shallow subtidal zone.     

大型蚤对五价砷抗性选择的响应

金属污染对栖息在该环境中的生物具有强大的选择力,生物若能进化出对该金属的抗性则能在该环境中生存下去,否则将会灭绝。人工模拟的选择方法可以用来研究生物对金属的抗性进化。为了探索大型蚤(Daphnia magna)是否能进化出对五价砷(As(Ⅴ))的抗性,采用多代选择的方法对其进行了As(Ⅴ)诱导的抗性响应研究。依据本实验室大型蚤对As(Ⅴ)的96h半致死浓度(4.25 mg·L~(-1)),试验选取As(Ⅴ)亚致死浓度(8.0 mg·L~(-1))对大型蚤进行选择,每代选择30%~50%对As(Ⅴ)耐受性高的大型蚤转移至不加As(Ⅴ)环境下继续繁殖得到下一代,并重复该选择过程至获得第五代(F5)终止试验。以选择组F5代及对照组F5代大型蚤为测试目标,考察其在As(Ⅴ)继续暴露下的存活时间以期获得具As(Ⅴ)抗性大型蚤。结果显示,在F5代中,选择组大型蚤在As(Ⅴ)(8.0 mg·L~(-1))暴露下的存活时间相比对照组显著延长175%,证实了大型蚤对As(Ⅴ)的进化抗性。进一步研究发现,选择组F5代与对照组F5代相比繁殖力下降19.96%,平均每批产仔量降低15.71%。这表明经过五代人工选择后,大型蚤能够进化出对As(Ⅴ)的抗性,而这种抗性的进化伴随以生物适应性参数的降低为代价。另外,大型蚤对这种抗性的获得机制(对As(Ⅴ)的累积和脱毒机制)仍需进一步研究。     

水体低氧的早期暴露对青鳉(Oryzias latipes)后期的生长、性别比和繁殖能力的影响

水体低氧已是全球性生态问题,常以季节性、偶发性和昼夜间等不同形式存在于不同的水体中。长期低氧可影响鱼类正常的生长和繁殖,但鱼类早期生活阶段暴露于不同形式的低氧后,后期的生长和繁殖是否会受到不利影响,目前研究甚少。本研究在实验室模拟了连续低氧(2.8 mg·L~(-1)DO)(H1)、昼夜低氧(H2)和发生在胚胎器官形成时期的偶发性低氧(H3)等3种情景对青鳉胚胎的发育影响,评估了这一早期暴露对青鳉后期的生长、存活和繁殖的影响。我们发现,3种低氧方式都可以显著延长青鳉胚胎的孵化周期,引起胚胎卵黄囊吸收和鱼鳔发育异常;暴露结束120 d后,H1组青鳉成鱼的畸形率显著升高、存活率和生长速度都显著下降;H1、H2和H3组中成鱼的雌雄比都发生了改变,鱼群中以雄鱼为主,且产卵量和受精率都显著下降。结果表明,鱼类早期胚胎发育阶段所受到的低氧暴露可对后期生长和繁殖产生不利影响,对子代补充和种群稳定产生重要影响;鱼类关键发育期所经历的低氧事件,以及昼夜低氧事件所产生的生态后果不容忽视。     

沉积物中六氯苯对摇蚊幼虫的慢性毒性效应

以淡水底栖动物花翅羽摇蚊(Chironomus kiiensis)幼虫为受试生物,研究了沉积物中六氯苯(HCB)对其28 d的慢性毒性效应,观察摇蚊幼虫的存活情况和活动行为,以死亡率、羽化率和羽化时间为受试终点,计算28 d试验后沉积物中HCB对摇蚊的半数致死浓度(lethal concentration 50,LC50)以及50%羽化时间(50%emergence time,EmT50)。结果表明,HCB对摇蚊28 d的LC50为59.8 mg·kg-1,对摇蚊羽化率的半数效应浓度(half maximal effective concentration,EC50)为59.8 mg·kg-1。与大多数污染物不同,HCB有促进摇蚊幼虫筑巢行为和羽化的作用,随着HCB染毒浓度升高,摇蚊幼虫筑巢行为加强,EmT50缩短。暴露于高浓度HCB(21.6 mg·kg-1)时,摇蚊的EmT50与对照相比明显缩短,尤其对雄性摇蚊影响更大。但与对照相比,HCB对羽化摇蚊的性别比没有很大影响。     

Modeling thermal effect on growth of chinese shrimp, Penaeus chinensis (Osbeck)

A couple of experiments were conducted to estimate the optimal temperature effect on growth of Chinese shrimp (Penaeus chinensis). The equation describing growth-temperature relationship derived from the first experiment with temperature ranging from 16° to 31°C was found linear as the following:

G = -0.005667 + 0.001103 T

,where G and T are daily growth rate and temperature, respectively.The second experiment indicated that the daily growth rate was a quadratic function of temperature at the limits of 27° and 35°C. The equation was

G = -0.339587 + 0.023476 T − 0.000375 T²

.The optimal temperature in terms of maximum growth was 31.26°C.     

Assessing environmental factors in red spruce (Picea rubens Sarg.) growth in the Great Smoky Mountains National Park, USA: From conceptual model, envirogram, to simulation model

This study provides a method for assessing a multiplicity of environmental factors in red spruce growth in the Great Smoky Mountains National Park (GSMNP) of Southeastern USA. Direct and indirect factors in the annual growth increment are first organized into a schematic input-output envirogram (ARIRS), and this information is then used to construct a simulation model (ARIM). The envirogram represents a structured conceptualization of most environmental factors involved in growth, as developed from relevant literature. This interdisciplinary synthesis distinguishes direct vs. indirect factors in growth and takes account of the systems ecology concept that indirect factors may be as important as or more important than direct ones in regulating growth. The ARIRS envirogram summarizes hierarchically organized, within- and cross-scale, local-to-global interactions, and its construction makes it obvious that growth is influenced by many cross-scale spatiotemporal interactions. More research on genecology is still needed to clarify the role of phenotypic plasticity and adaptive capacity in nutrient cycling, global change, and human disturbance.     

Effects of temperature variation on TSD in turtle (C. picta) populations

We formulate a two-sex model of temperature-dependent sex determination (TSD) for a freshwater turtle (C. picta) population. The aim is to understand how environmental temperature variations and nest heat conduction properties affect the long term dynamics of the population. This is a key to understanding how global temperature changes may affect their survival. With stochastic inputs of ambient temperature and solar radiation, the model uses the heat equation to determine the temperature in the egg layer in the nest; in turn, this determines the sex ratio in the egg clutch using a variable degree-day model. Finally, a nonlinear Leslie type, stage-based, two-sex model, is used to determine the long term male and female populations. A two-sex model is required because of different development rates for males and females. The model is flexible enough to enable other researchers to examine the effects of temperature variation variations on other species with TSD, e.g., crocodilians, reptilians, as well as other turtle species. It can be adapted to study effects of nest location, soil type, rain events, different incubation periods, and density effects, for example, the dependence of the mating function on the ratio of males to females and each’s contribution to the sex of hatchlings. Modifications can be easily made to fit a specific life history traits. The model is a beginning step in understanding the long term, high fitness shown by many reptile species with TSD, and it may suggest to experimentalists what data may be relevant to these issues; it can also be useful to wildlife managers in developing strategies for intervention if needed. Among the principal findings are that temperature variability and detailed nest heat conduction properties may buffer projected negative effects on a population.     

Strong maternal effects and extreme heterogeneity of progeny development in the caridean shrimp Sclerocrangon boreas (Crangonidae)

Sclerocrangon boreas is uncommon among marine coastal carideans in having a non-dispersing, abbreviated (2-stage) larval phase. We investigated the implications of this strategy in terms of fecundity, offspring provisioning and brood care in S. boreas from the St. Lawrence Gulf and Estuary in 2009–2010. Fecundity scaled positively to female body size but was low due to the production of large, lipid-rich eggs. Offspring size at all stages of development was positively related to female size. Larval traits and lipid dynamics indicate obligatory lecithotrophic development from hatching to juvenile. The larva becomes a juvenile on the mother and remains associated with her for sometime after. The co-occurrence of early egg stages among many juveniles in some clutches raises the possibility that maternal care of juveniles includes the provisioning of trophic eggs or eggs reclaimed from other females.     

壬基酚、五氯酚及硝基苯对端足类河蜾蠃蜚(Corophium acherusicum)的毒性效应

为检测海洋中环境激素及芳烃类化合物对端足类生物的污染危害,实验选择端足类河蜾蠃蜚(Corophium acherusicum)为受试生物,研究了其在壬基酚、五氯酚、硝基苯三种有机污染物暴露下的96 h急性致死毒性效应和7 d慢性DNA损伤毒性效应。计算获得壬基酚、五氯酚和硝基苯对河蜾蠃蜚的96 h半致死浓度(LC50)分别为70、465、25 000μg·L-1,三种有机污染物对河蜾蠃蜚的毒性强弱顺序为壬基酚五氯酚硝基苯。运用碱解旋法检测壬基酚、五氯酚和硝基苯对河蜾蠃蜚DNA损伤的程度,计算得到7 d半效应浓度(EC50)分别为30、256、11 000μg·L-1。实验结果表明:三种有机污染物浓度的不断加大,引起河蜾蠃蜚DNA损伤程度的不断增加,呈显著的剂量-效应关系。     

The effects of subchronic exposure to NeemAzal T/S on zebrafish (Danio rerio)

The objective of the study was to investigate the subchronic effects of the insecticidal preparation NeemAzal T/S at concentrations of 3, 10 and 30?mg/L on the mortality, growth and histopathology of juvenile zebrafish (Danio rerio), as well as its related effects on selected indices of oxidative stress during a 28-day toxicity test. The juvenile growth toxicity test was performed according to OECD Guidelines 215 (Fish, Juvenile Growth Test). The results of this study indicate that these tested concentrations of NeemAzal T/S (containing 1% of the active ingredient azadirachtin A) affect fish growth and have a negative influence on the indices of oxidative stress in the juvenile stage of zebrafish, as well as cause mild histopathological changes in liver tissue.