湖北武湖日本沼虾的生长特性   总被引：13，自引：0，他引：13  

刘军  龚世园  何绪刚  张训蒲 《湖泊科学》2003,15(2):177-183

从1998年9月至1999年9月对人工养殖湖泊——武湖日本沼虾生长特性作了研究. 以月龄来研究日本沼虾的生长,研究结果表明日本沼虾在7-1月份(1-7月龄)呈等速生长,在2-6月份(8-12月龄)呈异速生长.日本沼虾体重(W)与体长(L)呈幂函数相关,但在7-1月份时其b值接近于3,而在2-6月份时其b值明显小于3,其关系式如下: 1-7月龄:W♂=0. 0148L3. 2419(r=0. 9978,n=390),W♀=0. 0206L3. 0117(r=0. 9968,n=372); 8-12月龄:W♂=0. 0857L2. 1788(r=0.9854,n=188),W♀=0. 1450L1. 8165(r=0. 9974,n=278). 1-7月龄雄虾的生长规律符合Von Bertalanffy方程,雌虾的生长规律符合Logistic方程;8-12月龄雌雄虾的生长规律都符合Logistic方程.  相似文献   

TBT toxicity on the marine microalga Nannochloropsis oculata     

M. Sidharthan  Kim Shin Young  Lee Hoe Woul  Park Kwan Soon  Hyun Woung Shin   《Marine pollution bulletin》2002,45(1-12)

Commercial antifouling formulations containing TBT are the major source of organotin contamination in coastal waters. In view of the persisting TBT residues (13 ng Sn l⁻¹) in the coastal waters of South Korea, an attempt has been made to evaluate the growth response and biochemical composition of laboratory-cultured Nannochloropsis oculata to TBT toxicity. It is evident that the persisting concentration level of TBT is high enough to cause adverse effect on the microalgal species. The EC₅₀ (24 h) was found to be at 0.89 nM level of TBT for this marine eustigmatophyte N. oculata. Photosynthetic pigment content was significantly affected. At elevated TBT concentrations of 1.0 nM, especially pronounced changes in biochemical composition was found. TBT tolerance of N. oculata and its growth as well as biochemical responses are discussed.  相似文献   

襄十宛增长三角空间结构特征研究     

陈静  郝群会 《云南地理环境研究》2010,22(1):71-75

增长三角作为一种新型的区域经济合作模式,自从出现就获得了迅速发展,引起了广泛关注。襄樊、十堰和南阳3市地处中部地区,通过近些年的发展已经取得了一定的经济成就,但经济水平仍显不足。同时也面临着周边武汉经济圈、中原城市群、成渝都市圈和关中城市群竞争,有被边缘化的危险。因此,襄十宛三角地区做为中部重要区域要想在未来的区域竞争中取得主动权,必须要有所作为。正是这种目的,提出了构建襄十宛增长三角的构想。  相似文献   

中国南亚热带水库敞水区春季轮虫群落结构:基于分类特征和功能性状的分析     

陈旭繁  黄珂  章洁香  黄琦  刘平  韩博平 《湖泊科学》2021,33(5):1490-1499

轮虫是淡水后生浮游动物中种类最丰富的类群,是水体生态系统食物链的关键环节.很多种类的轮虫对环境变化敏感,环境条件的改变能够导致其群落结构的快速变化,因此,轮虫群落的组成与变化可从生态位角度得以解释.物种的功能性状可提供更强的生态适应性信号,轮虫的个体大小是反映其代谢与行为的综合性状,而咀嚼器、防御结构及防御行为则反映了它们对食物利用和应对捕食等方面的功能性状,轮虫群落中物种的这些功能性状组成反映了食物资源和捕食压力等对群落组成的选择作用.为了解我国南亚热带水库轮虫群落的结构特征,于2018年春季(3—5月)采集了我国华南地区43座水库敞水区的浮游动物定性样品和定量样品,同时测定了水温、水深、水体透明度及叶绿素a浓度等指标.共采集到轮虫19属45种,主要为营浮游生活的种类,异尾轮属(Trichocerca)和臂尾轮属(Brachionus)的种类最多,分别有10和7种.在轮虫个体大小上,群落中体长≤150 μm个体的丰度和生物量均占绝对优势(分别为83.11%和53.10%),体现出热带、亚热带地区轮虫群落以小个体种类占优势的一般特征;具有槌型咀嚼器、杖型咀嚼器的轮虫为优势咀嚼器功能群,分别占57.78%和33.14%;具背甲与棘刺的轮虫为主要优势防御结构功能群(66.59%).南亚热带水库春季轮虫群落在食物利用及应对捕食压力上的特点明显,冗余分析表明轮虫群落的种类组成及性状功能群的丰度组成显著地受到食物、温度及竞争的影响.  相似文献   

环境因子对浮游甲壳动物群落功能多样性的影响     

王松波  史昭锦  耿红  吴来燕  曹艳敏 《湖泊科学》2021,33(4):1220-1229

基于功能性状的生物多样性分析是当前生态学研究中的常用方法之一.浮游动物作为水生态系统食物网的重要组成成分,其功能多样性受关注的程度远不如其重要性.本文通过对14个水体浮游甲壳动物群落结构的研究,分析了环境因子对其功能多样性指数,包括功能丰富度(FRic)、功能均匀度(FEve)、功能离散度(FDiv)和功能分散度(FDis),以及功能群分布的影响.结果显示,亲缘关系近的物种(在分类学上相近)由于具有相似的功能性状,均很好地聚为一类.相关分析显示,FRic、FEve和FDiv与环境因子之间不存在显著的相关关系;FDis与总溶解性氮、总溶解性磷、氨氮和悬浮物C/P比存在显著的相关关系.回归分析发现,随着水体总溶解性磷浓度的上升,浮游甲壳动物的物种数表现出下降趋势,功能群数量、功能群Shannon-Wiener指数和FDis均显著下降;另外,FRic和FDis与功能群数量均呈显著正相关.这些结果表明水体富营养化能促进浮游甲壳动物群落功能性状的趋同,环境选择是群落结构变异的主要驱动力之一.  相似文献   

Sublethal effects of a chlorinated and heated effluent on the physiology of the mussel,Mytilus edulis L.: A reduction in fitness for survival?     

《Marine pollution bulletin》2014,78(1-2):123-131

Coastal power stations entrain large volumes of cooling water, requiring biocidal treatment to prevent biological fouling. Discharged effluent is both heated and contaminated with residual traces of biocide and so it is necessary to quantify the impacts of this discharge. Cooling water from Heysham 2 nuclear power station, NW England, UK, is discharged to the intertidal area, via a culvert (to minimise erosion and maximise dilution and dispersion by directing the effluent into the receiving water at all states of the tide) within which the effluent is contained at low water. The culvert and surrounding coastal area support a population of blue mussels (Mytilus edulis). Mussel health was determined along a gradient of exposure, using three physiological indices: Scope for Growth, Gonad Mantle Index and Somatic Condition Index (K Factor). The Mussels within the culvert exhibited reduced physiological index values compared to an external site. A trend was identified down the length of the culvert, representing a gradient of exposure and indicating a potential negative effect on growth and reproductive output.  相似文献   

Growth patterns and dynamics of mud cracks at different diagenetic stages and its geological significance     

Zhen-yu ZHAO  Yan-ru GUO  Yan WANG  Hong LIU  Qing ZHANG 《国际泥沙研究》2014,29(1):82-98

This paper discusses the growth stages,spatial structures,quantitative fitting relationships among various parameters,growth patterns and influencing factors of mud cracks by field survey,core observation and SEM analysis.The study shows that:(1) Mud crack growth can go through three stages,i.e.the syndiagenetic stage,the burial diagenetic stage(including early diagenetic stage,middle-late diagenetic stage) and the epidiagenetic stage.(2) Quantitative fitting relationships among various parameters allow a great significance to describe the spatial structure,the regional distribution and the growth environment of mud cracks.(3) Mud crack growth has three models,such as the unilateral growth model including the linear growth pattern,the curvilinear growth pattern and the bifurcation growth pattern,the multilateral growth model including the inteisectional growth pattern,the join growth pattern and the dispersed growth pattern,and the mixed growth model including the combination of any patterns listed above.(4) Modern mud crack growth usually undergoes four stages.Sand beds in sand-mud rhythmic strata can play a lubricative role on crack growth and provide enough sandy deposits for filling cracks.(5) Mud crack growth usually produces bifurcation and bifurcation angles which are mostly 120° or 90° that are related to sediment heterogeneity and released energy.(6)Factors affecting mud crack growth cover many aspects:clay content and salinity can control the number of mud cracks in different areas;terrain can control mud crack morphology;and different sedimentary cycles can control the growth patterns and filling models of mud cracks.  相似文献   

Population dynamics of cryptogenic calcarean sponges (Porifera,Calcarea) in Southeastern Brazil     

Fernanda F. Cavalcanti  Luís Felipe Skinner  Michelle Klautau 《Marine Ecology》2013,34(3):280-288

The calcarean sponge Paraleucilla magna is classified as being an invasive species on the Mediterranean Sea, where it causes economic damages to mollusc farms. On the Brazilian coast, this species is considered to be cryptogenic, and information on its ecology is scarce. The same is true for Sycettusa hastifera, another calcarean sponge with a worldwide distribution. Data on the ecology of these species could help in elucidating their potential to become a threat if they are found to be exotic species in Brazil. In the present work, we studied habitat selection, growth and mortality of early juveniles of P. magna and habitat selection of S. hastifera in a Marine Reserve from Southeastern Brazil, where these species are abundant in the benthic community. Granite plates were used for habitat selection analysis, varying in substrate inclination (vertical and horizontal) and exposure to light and hydrodynamism (exposed and sheltered). To analyse the growth and mortality rates, sponges were mapped and then measured once a week for 10 weeks. If a monitored sponge was not found in the following week, it was considered to be dead. Our results showed that, although P. magna and S. hastifera are capable of inhabiting substrates exposed to different environmental conditions, they showed habitat preferences. Growth of the juveniles of P. magna seemed not to have damaged any neighbouring invertebrates. The mortality of juveniles of this species was higher during the first 2 weeks of life but its causes could not be elucidated.  相似文献   

高原湖泊鱼类生长特性与形态差异研究   总被引：1，自引：0，他引：1  

费骥慧  邵晓阳 《海洋与湖沼》2012,43(4):789-796

根据2009年8—11月洱海流域采集的2991尾鱼类样本,研究了其生长特性与形态差异。结果表明,洱海流域大部分鱼类表现为匀速生长或近匀速生长,但有两种鱼类(中华青、大理裂腹鱼)呈现强异速生长。肥满度以吃食性鱼类最高(鲫、鲤、团头鲂),滤食性鱼类次之(鲢、鳙)。对主要优势种——麦穗鱼、鲫的形态分析表明,洱海麦穗鱼、鲫种群与西湖、茈碧湖、海西海三个湖泊的麦穗鱼、鲫种群在形态上均无显著差异。西湖、茈碧湖、海西海三个湖泊的麦穗鱼种群之间以及鲫种群之间均存在种群间差异(C.D<1.28),其中茈碧湖、海西海两个湖泊的鲫种群在眼径/头长性状上的差异达到亚种水平(C.D=1.5)。  相似文献   

温度突变对大海马(Hippocampus kuda)幼体生长、组分及酶活力的影响   总被引：1，自引：0，他引：1  

孙彬  陈舜  徐永健  戴广谱 《海洋与湖沼》2012,43(1):67-72

以大海马幼体为实验材料,通过设置不同的温度突变组(温度从23℃突变至15℃、28℃和33℃)的方法,对其生长、生化组分以及酶活力的影响进行了研究。结果表明,实验结束后,28℃温度组的大海马幼体生长指标、蛋白含量、能值显著高于23℃对照组(P<0.05),而15℃、33℃温度组的各项指标则显著低于对照组(P<0.05);此外,温度突变组的大海马幼体的酶活力均有先升后降的趋势,在1d后出现峰值,4—6d各个温度组趋于稳定,到实验第15天时,28℃温度组的SOD、ACP活力和MDA的含量已处于23℃对照组水平(P>0.05),CAT、AKP活力显著高于23℃对照组(P<0.05)。而15℃、33℃温度组的SOD、CAT活力降至低于23℃对照组水平(P<0.05),15℃温度组的ACP、AKP活力则低于23℃对照组水平(P<0.05),MDA的含量在15℃、33℃温度组随时间延长而增加。  相似文献