物理及生物技术在密云水库富营养化防治中的应用

为防治密云水库富营养化问题,应用部分物理和生物技术进行现场试验。吸附性材料净水试验后,试验区内水中氮的浓度和磷的浓度比对照区都有所下降,这将对藻类生长所需的营养物质量起到一定的控制作用。水葫芦净化水体试验说明,试验区内水体的总磷和总氮浓度皆低于对照水体的,这将控制藻类生长所需的营养物质量,即控制藻类的生长速度。机械除藻试验后,水中的叶绿素含量比除藻前下降60%~100%。表底层水体交换试验后,试验区内表、中层水体的温度有所下降,温度降低将抑制表、中层水体中藻细胞的繁殖速率,对水华的发生将起到一定的抑制作用。     

Ontogenetic shifts and temporal changes in the trophic patterns of the deep‐sea red shrimp,Aristaeomorpha foliacea (Decapods: Aristeidae), in the Eastern Ionian Sea (Eastern Mediterranean)

The purpose of this paper is to provide the first detailed data concerning the diet and feeding activity of the giant red shrimp, Aristaeomorpha foliacea, in the Eastern Ionian Sea (Eastern Mediterranean), in relation to season, size class and sex. Feeding activity in A. foliacea was intense, based on its low vacuity index and high prey diversity, with a diet dominated by mesopelagic prey and less frequent occurrence of benthic taxa. Giant red shrimp displayed a highly diversified diet that exhibited slight seasonal fluctuations. The diets of both sexes consisted of 60 different prey categories belonging chiefly to three groups: crustaceans (e.g. decapods, such as Plesionika spp. and Pasiphaeidae, amphipods), cephalopods (mainly Enoploteuthidae) and fishes (Myctophidae, Macrouridae). These three prey categories accounted for 72–82% of the relative abundance and total occurrence for males and 70–88% for females, respectively. Variation in food availability, as well as increased energy demands related to gonad development and breeding activity, appear to be critical factors driving temporal changes in feeding strategy. Feeding activity increased during spring and summer, which coincides with reproductive activities (mating, gonad maturation, egg‐laying). Females seem to be more active predators than males, consuming prey with greater swimming ability. However, ontogenetic shifts in diet were also apparent, despite high dietary overlap among small, medium and large females. Large individuals, which are more efficient predators, selected highly mobile prey (e.g. fishes), whereas small individuals consumed low‐mobility prey (e.g. copepods, ostracods, tanaids and sipunculans).     

脊尾白虾的行为学观察研究

在高密度室内饲养条件下,观察了脊尾白虾(Exopalaemon carinicauda)的摄食、相残、运动、蜕皮、间隔、攻击和防御行为。试验结果表明,脊尾白虾摄食行为活跃,运动行为多样,在饥饿或个体较大差异条件下具有一定程度的相残行为,蜕皮行为表现出一定的特殊性,常经数天多次蜕皮行为特征后才能将旧壳蜕下,间隔行为不明显,攻击频率不高。另外,通过设置不同投喂组和投喂间隔时间观察比较了索饵率和相残率,结果表明,索饵率在第8小时已基本达到最高,相残率随投喂间隔时间的延长和空间密度的增大而升高。     

刺参对不同生境中沉积物粒度的选择

2009年5月26日～6月16日采集日照前三岛海域(90.67g±23.542g)、青岛胶州湾海域(53.96g±14.742g)、烟台养殖围堰(82.99g±32.942g)的刺参(Apostichopus japonicus)。使用CILAS940L型激光粒度仪对刺参肠道内含物及自然沉积物的粒度进行分析。结果表明,野外调查中,刺参肠道内含物与表层沉积物的粒度有显著差异。刺参摄食的颗粒中,90%以上的颗粒粒径为1～80μm。刺参对沉积物颗粒粒度的选择在不同养殖系统中没有差异。正常生长阶段,刺参成体摄食的颗粒大小与刺参的体质量呈负相关。     

方斑东风螺早期发育过程中几种消化酶的活性

将方斑东风螺Babylonia areolata(Link)的早期发育从早期面盘幼体到变态后15d的稚贝分成6个阶段,分别测定各阶段蛋白酶(P)、脂肪酶(L)、淀粉酶(A)和纤维素酶(C)活性。研究结果表明,随着幼体发育的推进,蛋白酶比活力逐渐减小,脂肪酶比活力逐渐增加,淀粉酶和纤维素酶比活力则在变态前逐渐增加,而变态后逐渐减小。比较A/P和(A C)/(P L)两种指标指示方斑东风螺幼体发育过程中的食性变化,提出(A C)/(P L)用于指示方斑东风螺食性变化更合理、准确。综合比较幼体发育各阶段4种消化酶活性,发现在面盘幼体向稚贝变态期间,幼体消化能力最弱,原因与幼体的变态过程有关。实验结果也验证了贝类具有分泌纤维素酶的能力,该酶在东风螺对纤维素分解中占主导地位。     

温度和盐度对两种海洋桡足类动物摄食和代谢的影响

本研究在实验室模拟生态条件下,以两种常见的海洋桡足类动物为受试生物,着重研究了温度和盐度变化对火腿许水蚤(Schmackeria poplesia)和拟长腹剑水蚤(Oithona similis)的滤水率、摄食率、耗氧率和排氨率的影响,统筹分析了两种海洋桡足类响应温度和盐度变化的摄食与代谢策略,以期为两种海洋桡足类的室内培养提供理论支持和技术指导。结果发现:(1)在5—30°C的温度范围内两种桡足类动物的摄食与代谢均呈现随温度升高而先升高后降低的变化趋势,其中火腿许水蚤的摄食率、滤水率、耗氧率和排氨率的最大值均出现在15°C,而拟长腹剑水蚤则在25°C到达峰值,说明拟长腹剑水蚤对温度具有较高的耐受性。(2)当暴露于不同盐度(15—35)时,火腿许水蚤可在低盐度(<25)条件下保持较高的摄食能力,且当盐度为25时其摄食率、滤水率达到峰值,之后便显著下降;拟长腹剑水蚤则在盐度为30时开始下降。前者的代谢能力在盐度为25时开始下降,后者在高盐度(35)时代谢能力依然有回升的趋势,说明拟长腹剑水蚤对盐度的耐受性更强。而火腿许水蚤及拟长腹剑水蚤对低盐度(20—25)有一定的偏好,二者通过强...     

黄海大型底栖动物功能摄食类群的空间格局

本研究根据2000年10月、2001年3月、2003年6月、2004年1月、2011年4月和8月黄海大型底栖动物调查资料(仅2011年4月和8月航次测定水体和沉积物环境数据)对黄海大型底栖动物功能摄食类群的空间格局及其与环境因子的相互关系进行研究。结果表明,黄海大型底栖动物功能摄食类群相对丰度较高的为肉食者、食底泥者和滤食者。黄海大型底栖动物食底泥者和肉食者相对丰度高值出现在2011年8月航次,分别为44.88%和39.04%。黄海大型底栖动物空间分布以黄海冷水团区域为参照,黄海大型底栖动物肉食者主要分布在黄海冷水团边缘靠近海州湾东侧。食底泥者主要分布在黄海近岸及黄海冷水团边缘。滤食者主要分布在黄海冷水团中央区域。运用摄食多样性指数(J′FD)对黄海水域生态质量和底栖群落健康状况进行评价,结果表明,黄海近岸海域生态质量状况较低。对2011年4月和8月航次黄海大型底栖动物功能群与环境因子进行冗余分析,结果表明,底层水温度、盐度、水深和中值粒径是影响黄海大型底栖动物功能摄食类群的主要环境因素。     

阿根廷巴塔哥尼亚陆架拉氏南美南极鱼(Patagonotothen ramsayi)不同组织中脂肪酸分布及食物来源指示

作为南美南极鱼科中数量最为丰富的一个种,拉氏南美南极鱼(Patagonotothen ramsayi)在巴塔哥尼亚海域食物网能量流动中起着重要的传递作用。目前针对该鱼种的营养及摄食生态学研究主要集中于反映短期摄食的传统胃含物分析上。为此,本研究分析了拉氏南美南极鱼3种组织(肌肉、肝脏和性腺)中脂肪酸含量及分布情况,并就3种组织中的脂肪酸是否能表征其食性及食性转换进行了探究。结果表明,拉氏南美南极鱼体内共检测出27种脂肪酸;由于涉及生长、繁殖等因素影响,肝脏、性腺组织对于脂肪酸的储存及使用情况并不适用于指征食性,而肌肉组织更新时间相对较长,故能够较好地反映其对食物中脂肪酸的吸收。对不同体长组拉氏南美南极鱼肌肉组织中脂肪酸分析可知,未成熟拉氏南美南极鱼(100～240 mm)主要摄食浮游性生物;随着体长增加对底栖生物的摄食也随之增加,由浮游性摄食方式转变为浮游-底栖性摄食。另外,因拉氏南美南极鱼摄食一定量的渔业丢弃物,导致腐生食物链和捕食食物链的贡献率特征弱化。研究结果进一步显示,针对大洋性鱼类,与肝脏和性腺相比,肌肉组织脂肪酸更适用于表征食物来源。     

条斑星鲽外部形态特征与内部组织器官的初步研究

采用传统的形态学和解剖学方法,对条斑星鲽(Verasper moseri)人工种鱼的外部形态特征及内部组织器官进行了系统的观测和描述。结果表明:比例性状体长为体高的1.67～2.01倍、为头长的3.47～3.90倍;头长为头高的1.07～1.49倍,为吻长的5.11～8.18倍,为眼径的4.60～6.33倍,为眼间距的11.3～14.3倍;尾柄长为尾柄高的0.51～0.63倍;可数性状背鳍、臀鳍、腹鳍、胸鳍、尾鳍鳍条数分别为75～80、53～56、6、12、19;侧线鳞数88;食道粗短,胃发达且分化明显,肠在腹腔内呈一个盘曲,比肠长(肠长/体长)为0.55～0.64,以上表明条斑星鲽为典型的肉食性鱼类;成熟雌鱼两卵巢形态不对称,其中无眼侧略大;一对"矢耳石"呈椭圆形,薄而透明,对向排列。     

DIETARY PHOSPHORUS REQUIREMENT OF YOUNG ABALONE, HALIOTIS DISCUS HANNAI INO

An experiment was performed to determine the dietary phosphorus requirement of the young abalone,Haliotis discus hannai. Five semi-purified diets were formulated to provide a series of graded levels of dietary total phosphorus (0.23%–1.98) from monobasic potassium phosphate (KH2P04). The brown alga,Laminaria japonica, was used as a control diet. Similar size abalone were distributed in a single-pass, flow-through system using a completely randomized design with six treatments and three replicates each treatment. The abalone were hand-fed to satiation with appropriate diets in excess, once daily at 17:00. The feeding trial was run for 120-d. Survival rate and soft-body to shell ratio (SB/S) were constantly maintained regardless of dietary treatment. However, the weight gain rate (WGR), daily increment in shell length (DISL), muscle RNA to DNA ratio (RNA/DNA), carcass levels of lipid and protein, soft-body alkaline phosphatase (SBAKP), and phosphorus concentrations of whole body (WB) and soft body (SB) were significantly (ANOVA, P<0.05) affected by the dietary phosphorus level. The dietary phosphorus requirements of the abalone were evaluated from the WGR, DISL, and RNA/DNA ratio respectively, by using second-order polynomial regression analysis. Based on these criteria, about 1.0%–1.2% total dietary phosphorus, i.e. 0.9%–1.1% dietary available phosphorus is recommended for the maximum growth of the abalone. Project 39670572 supported by the NSFC.