Negative Growth and Longevity in the Purple Sea Urchin Strongylocentrotus purpuratus (Stimpson)

Purple sea urchins were tagged, measured, and placed in a tidepool at Sunset Bay, Oregon. After 1 year, many animals had decreased in size. Accordingly, size is not necessarily a reliable index of age in Strongylocentrotus purpuratus; however, it is possible to conclude that these animals are relatively long-lived.     

遮蔽行为对海刺猬摄食、生长和性腺性状的影响

海胆遮蔽行为对于海胆的生长和发育的影响目前还不清楚,在实验室条件下,研究了遮蔽行为对海刺猬(Glyptocidaris crenularis)摄食、生长和性腺性状的影响.实验设两个对照组和一个处理组:对照组为无任何遮蔽条件的空白组和以堆积砖块创造的黑暗空间来满足海胆的掩蔽行为的掩蔽组,遮蔽组则以菲律宾蛤仔(Ruditapes philippinarum)的贝壳作为遮蔽物来满足海胆的遮蔽行为.结果显示:遮蔽组的海胆周摄食量要显著大于掩蔽组(P＜O.05),而空白组与遮蔽组和掩蔽组之间的差异不显著(P＞0.05);各组海胆的存活率没有显著差异(P＞0.05);空白组和遮蔽组海胆的壳径、壳高、体重要显著大于掩蔽组(P＜0.05),而空白组和遮蔽组之间没有显著性的差异(P＞0.05);空白组和遮蔽组的性腺湿重、性腺干重、性腺指数、壳湿重、壳干重、亚氏提灯湿重、亚氏提灯干重要显著大于掩蔽组(P＜0.05),而空白组和遮蔽组之间没有显著性的差异(P＞0.05);空白组的提灯指数要显著小于遮蔽组和掩蔽组(P＜0.05),而遮蔽组和掩蔽组之间没有显著的差异(P＞0.05).结果证明,遮蔽和掩蔽行为对海刺猬生长及发育的影响是有差别的,掩蔽行为对海刺猬的生长与发育造成了负面影响,而遮蔽行为在一定的生活环境条件下不会对其生长造成影响.研究表明,海刺猬的遮蔽行为反映了其对外界不利环境条件的一种适应性,且这种行为对其生长和发育的影响与掩蔽行为有所不同.至于海刺猬遮蔽行为的进化选择压力,目前的研究还不足以下定论,需要进一步深入的研究.     

不同实验生态环境对海刺猬遮蔽行为的影响

研究了较长时间生活在3种不同实验遮蔽条件下海刺猬(Glyptocidaris crenularis)的遮蔽行为特点.结果表明:不同生活环境下海刺猬都保持着遮蔽行为.生活在以贝壳作为遮蔽材料环境下(遮蔽组)和以砖块作为掩蔽材料环境下(掩蔽组)的海刺猬初次遮蔽耗时要显著短于生活在无遮蔽(或掩蔽)材料环境下(空白组)的海刺猬(N=3,P＜0.05).3组海刺猬用于遮蔽的贝壳总数和有遮蔽行为的海刺猬总数都呈现先增加后趋于平稳的趋势.掩蔽组有遮蔽行为的海刺猬总数要显著多于遮蔽组和空白组(P＜0.05),后两者差异不显著.3组海刺猬用于遮蔽的贝壳总数差异不显著(P＞0.05).海刺猬遮蔽时对两种贝壳(菲律宾蛤仔和贻贝)存在显著的选择差异(P＜0.05).生活环境中一段时间内遮蔽物的缺失并不会使其失去这种行为,但是会在一定程度上影响该行为的强度.因此,光照很可能是海刺猬遮蔽行为的一个进化压力,该行为也许只是作为一种避光策略.海刺猬对遮蔽材料具有显著的选择性,这可能与遮蔽材料自身特征和海刺猬的生理状态相关.     

Direct coupling of marine invertebrate spawning with phytoplankton blooms

Spawning of green sea urchins and blue mussels may be triggered by a heat-stable metabolite released by various species of phytoplankton. Mussels require a higher phytoplankton density for a maximum response than urchins, perhaps because mussels are exposed to higher concentrations of phytoplankton as a result of their filtering activity. Phytoplankton as a spawning cue appears to integrate numerous physical and biotic factors indicating favorable conditions for larval growth and survival. Evolution of similar direct coupling of the larval phase with phytoplankton blooms may be common among marine invertebrates.     

升温对不同管足颜色中间球海胆家系和红、白管足中间球海胆免疫相关酶活性及MDA含量影响的初步研究

为研究升温对不同管足颜色中间球海胆家系和红、白管足中间球海胆免疫相关酶活性及MDA含量的影响,实验设置不同温度梯度(15、20、22、24及26℃),分别对不同管足颜色海胆家系和红、白管足海胆体腔液中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、溶菌酶(LZM)及丙二醛(MDA)含量进行测定。结果显示：(1)随着水温升高,RR、RW、WR和WW家系中间球海胆SOD、CAT、POD、LZM活性均呈先升高后降低的趋势。SOD活性范围为2.39 ~4.36U/ml、2.79 ~5.17U/ml、2.71 ~4.97U/ml、3.66 ~5.69U/ml;CAT活性范围为63.02 ~112.76U/ml、62.47 ~169.37U/ml、66.40 ~140.77U/ml、72.29 ~149.20U/ml;POD活性范围为1.65 ~14.59U/ml、0.89 ~13.88U/ml、2.08 ~14.68U/ml、2.49 ~15.62U/ml;LZM活性范围为9.82 ~109.23U/ml、12.10 ~110.37U/ml、7.82 ~112.16U/ml、11.18 ~107.83U/ml;RR、RW、WR家系中间球海胆MDA含量呈先降低后升高的趋势,含量范围为0.97 ~2.34nmol/ml、0.82 ~2.40nmol/ml、0.96 ~2.23nmol/ml,WW家系中间球海胆MDA含量呈缓慢升高的趋势,含量范围为1.55 ~2.60nmol/ml。(2) 红、白管足中间球海胆SOD 、CAT、POD、LZM活性也均呈先升高后降低的趋势,红管足海胆MDA含量呈先降低后升高的趋势,白管足海胆MDA含量则呈升高的趋势。(3) 随着水温升高,RR家系海胆SOD活性对升温胁迫响应早于WW家系海胆;RW家系海胆CAT活性高于WW家系海胆;RR家系海胆MDA含量低于WW家系海胆MDA含量;红管足海胆SOD、POD活性均高于白管足海胆,其中POD活性变化差异显著(P<0.05);26℃时,红管足海胆MDA含量显著低于白管足海胆MDA含量 (P<0.05)。以上结果表明,以红管足海胆为亲本培育的海胆家系对升温响应更灵敏、更耐高温。     

Effects of fish in river food webs

Experimental manipulations of fish in a Northern California river during summer base flow reveal that they have large effects on predators, herbivores, and plants in river food webs. California roach and juvenile steelhead consume predatory insects and fish fry, which feed on algivorous chironomid larvae. In the presence of fish, filamentous green algae are reduced to low, prostrate webs, infested with chironomids. When the absence of large fish releases smaller predators that suppress chironomids, algal biomass is higher, and tall upright algal turfs become covered with diatoms and cyanobacteria. These manipulations provide evidence that the Hairston, Smith, Slobodkin-Fretwell theory of trophic control, which predicts that plants will be alternately limited by resources or herbivores in food webs with odd and even numbers of trophic levels, has application to river communitics.     

黑嘴病及生殖对虾夷马粪海胆五种生理生化指标的影响

对虾夷马粪海胆(Strongylocentrotus intermedius) 患“黑嘴病”及生殖后体腔液中5种生理生化指标进行了检测,结果表明病理情况下的虾夷马粪海胆过氧化氢含量和丙二醛含量明显高于对照组,而过氧化氢酶活性、超氧化物歧化酶活性和总抗氧化能力明显低于对照组,其中,过氧化氢含量、总抗氧化能力和超氧化物歧化酶活性差异显著（P<0.05）,丙二醛含量、过氧化氢酶活性差异极显著（P<0.01）。生殖后除过氧化氢含量外其他4种生理生化指标均降低,其中总抗氧化能力和丙二醛含量差异显著（P<0.05）,过氧化氢酶和超氧化物歧化酶活性差异极显著（P<0.01）。研究表明以海胆体腔液中丙二醛含量和过氧化氢酶活性作为海胆黑嘴病发生的监测指标是可行的。     

海胆营养生理研究进展

为深入开发海胆专用人工配合饲料,围绕海胆摄食生理和营养需求研究,综述了海胆主要经济养殖种类,投喂频率、养殖密度、环境因子(水温、溶氧、光线、氨氮)等因素对海胆摄食量的影响,以及海胆对蛋白质、碳水化合物、脂肪、脂肪酸、胆固醇、维生素和矿物元素的需求量,并在此基础上,探讨了在该领域未来研究的重点,以期为海胆人工配合饲料的开发提供帮助。     

The control of oxidant stress at fertilization.

Metazoan eggs alter their coats after fertilization to protect the early embryo. In sea urchins, this modification consists of a rapid, coordinated set of noncovalent macromolecular assembly steps that are stabilized by protein cross-linking. The sea urchin egg uses an oxidative cross-linking reaction that requires hydrogen peroxide and a secreted peroxidase and thus faces the challenge of oxidant stress at the beginning of its development. Protection from the deleterious effects of this oxidative mechanism is afforded by regulation of the production and utilization of oxidizing species. This regulation requires a specific protein kinase C-activated oxidase and ovothiol, an intracellular antioxidant.     

雌二醇对中间球海胆生长、性腺发育及胆固醇代谢的影响

为探讨雌二醇(estradiol)对体质量为(13.58±0.79)g的中间球海胆Strongylocentrotus intermedius性腺发育的调控机制,在室内水槽(200 L)中进行为期60 d的注射试验。试验分对照组、雌二醇(5μg/m L)注射组和他莫昔芬(tamoxifen)(25μg/m L)注射组,每3 d注射1次,并于第30天和第60天时两次取样测定海胆增重率(WGR)、性腺指数(GSI)、性类固醇激素含量和胆固醇合成相关基因的表达量。结果表明:注射雌二醇或他莫昔芬并未显著影响海胆的生长速率,却显著影响试验末期海胆的性腺指数,雌二醇组海胆性腺指数显著高于对照组和他莫昔芬组(P0.05);试验结束时,雌二醇组和他莫昔芬组海胆体腔液中雌二醇含量和性腺中胆固醇含量均显著高于对照组(P0.05),雌二醇组海胆性腺中雌二醇含量最高,显著高于对照组和他莫昔芬组(P0.05);雌二醇组海胆性腺和消化道中主要卵黄蛋白(MYP)基因均高于对照组,但均未有显著性差异(P0.05);雌二醇组和他莫昔芬组海胆性腺和消化道中性类固醇激素合成关键基因CYP17和胆固醇合成关键基因CYP51表达量均显著高于对照组(P0.05);他莫昔芬组海胆性腺中CYP17和CYP51基因表达量均低于雌二醇组(P0.05)。研究表明,注射雌二醇显著提高了中间球海胆性腺指数、体内雌二醇含量和雌二醇合成相关基因的表达量,这可能是雌二醇促进海胆性腺发育的调控机制。     

Brachiopods versus Mussels: Competition, Predation, and Palatability

Unlike other shell-enclosed marine invertebrates, articulate brachiopods are repellent to predators. Fish, sea stars, snails, and crabs all prefer bivalve molluscs such as mussels to articulates. The mussels tested are mobile and out-compete immobile articulates when space is limited. In subtidal field experiments, mussels alone and predators alone each reduced the survivorship of articulates. However, adding mussels to articulates in the presence of ambient predation increased brachiopod survivorship by diverting predation from the brachiopods to the mussels. Competition from mussels (or mussel-like bivalves) is a plausible cause of the post-Paleozoic decline of articulates.     

海水希瓦氏菌(Shewanella aquimarina)PCR检测方法

海水希瓦氏菌（Shewanella aquimarina）是虾夷马粪海胆的一种致病菌。为建立海水希瓦氏菌PCR快速检测方法,根据海水希瓦氏菌gyrB基因的高变区序列设计3对引物,随后进行了其特异性和灵敏度分析。结果显示引物SA-9可扩增出片段大小为815 bp的海水希瓦氏菌特异片段。引物可检测的最低细菌量为4.6×103 cfu/mL,最低DNA含量为3.15×10-4 ng/μL。表明以SA-9为引物的PCR检测方法特异性强,灵敏度高。 另外以该方法对海胆及其生境样品进行初步检测,发现健康海胆、养殖海水及投喂海带为阴性,而自然海域的海水具有一定量的海水希瓦氏菌。     

Topographically controlled fronts in the ocean and their biological influence

Headlands, islands, and reefs generate complex three-dimensional secondary flows that result in physical and biological fronts. Mixing and diffusion processes near these reefs and headlands are quite different from these processes in the open sea, and classical advection-diffusion models that were developed for the open sea are not valid near shore. Topographically generated fronts affect the distribution of sediments, and they aggregate waterborne eggs, larvae, and plankton. This aggregation influences the distribution and density of benthic assemblages and of pelagic secondary and tertiary predators.     

Alarm Response of Diadema antillarum

Diadema antillarum possesses a sensitive escape response to juices of crushed conspecific sea urchins. Stimulation usually results in urchins moving rapidly downcurrent. Strong species specificity of the response suggests that it is an adaptation to reduce predation. Diadema antillarum also responds with a running response to contact with Cassis tuberosa, a known predator.     

棘皮动物体腔细胞的研究进展

棘皮动物是在脊索动物后分布在海洋中的第二大后口动物。体腔细胞是棘皮动物机体免疫防御的重要组成部分,发挥着重要的免疫防御作用,具有吞噬包裹、氧化杀灭、创伤修复和凝集等多种防御功能。从体腔细胞类型、功能和发生来源3个方面综述了海星、海胆和海参3种主要棘皮动物的体腔细胞研究进展,以期为棘皮动物体腔细胞免疫防御机制研究提供参考。     

不同地区野生大豆生物学特性的比较分析

对吉林省和外地收集的野生大豆进行生物学特性调查,并对其成分进行分析.结果表明:1)大部分吉林野生大豆的花色为紫色,外来野生大豆的花色为白色;2)吉林野生大豆的种子有泥膜、无光泽,平均百粒重为2.06 g,属典型的野生大豆;而外来野生大豆的种子无泥膜、有光泽,平均百粒重为5.45 g,属半野生大豆;3)吉林野生大豆种子的蛋白质平均含量为45.75%,高于外来野生大豆的平均含量44.63%;4)吉林野生大豆种子的油分平均含量为19.72%,低于外来野生大豆的平均含量20.59%.     

Rates of DNA sequence evolution differ between taxonomic groups

The mutation rates of DNA sequences during evolution can be estimated from interspecies DNA sequence differences by assaying changes that have little or no effect on the phenotype (neutral mutations). Examination of available measurements shows that rates of DNA change of different phylogenetic groups differ by a factor of 5. The slowest rates are observed for higher primates and some bird lineages, while faster rates are seen in rodents, sea urchins, and drosophila. The rate of DNA sequence change has decreased markedly during primate evolution. The contrast in rates of DNA sequence change is probably due to evolutionary variation and selection of biochemical mechanisms such as DNA replication or repair.     

Extinctions and introductions in the new zealand avifauna: cause and effect?

New Zealand, like many other islands, has suffered extinctions of native species and successful introductions of exotic species. It has been uncertain whether the introductions caused the extinctions or whether the extinctions permitted the introductions. On New Zealand's Hauraki Gulf islands, which are unusual in their near lack of introduced mammalian predators and complete lack of mammalian browsers, exotic bird species abundant in mainland New Zealand forest and reaching these islands are virtually absent from unmodified forest. Exotic bird species disappeared from Cuvier Island's forest after elimination of mammalian predators and browsers. Hence extinctions of native species were not due to competition from introduced species but to other factors (such as mammalian predators and habitat alteration). Only after decimation of native species and forest alteration by browsing mammals could exotic birds invade forest.     

基于DEM和NDVI的南京紫金山国家森林公园雨洪影响研究

城市丘陵型森林公园因其特殊地形地貌所带来的雨洪问题,严重影响着城市周边雨洪安全。以南京紫金山国家森林公园为例,基于数字高程模型(DEM)和归一化植被指数(NDVI)分别对其雨洪产生因素进行分析,模拟地表径流,得出易受雨洪影响的区域,并从源头、途径层面分析易受雨洪影响区域的形成原因。结果表明,利用DEM与NDVI构建的数据模型模拟的径流渠道和高雨洪风险区域与实际相符,可为雨洪管控提供理论依据。并针对源头、途径、终端三个层面提出全过程雨洪管控策略,强调源头控制与过程管控,从而充分发挥紫金山国家森林公园雨洪调控功能,完善城市生态安全格局,保障城市雨洪安全。     

海刺猬和中间球海胆性腺的组织学和组织化学

对海刺猬Glyptocidaris crerularis和中间球海胆Stronylocentrotus intermedius性腺的组织学和组织化学进行了比较研究。结果表明,两者性腺结构均为滤泡型,滤泡由生殖细胞和营养细胞组成,随着生殖细胞的发育成熟,营养细胞中颗粒逐渐减少,当生殖细胞排放后,营养颗粒的数量逐渐增加,且中间球海胆的营养颗粒数量较海刺猬多。观察和分析了海刺猬和中间球海胆的雌、雄生殖细胞、营养颗粒、滤泡细胞的DNA、RNA、多糖、蛋白质和结合脂类的分布、数量及其变化,发现中间球海胆滤泡中营养颗粒的多糖和蛋白质含量比海刺猬高,其它指标两者都很相近。