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1.
不同饵料系列对漠斑牙鲆苗种培育效果的影响   总被引:2,自引:0,他引:2  
报道了不同饵料系列对漠斑牙鲆苗种成活率和生长率的影响.32.0万粒的受精卵经57 d培育,共获得全长2.7~5.5 cm的鱼苗16.6万尾.在仔鱼开口后自始至终加投配合饵料的饵料系列组(B组)的成活率比在35日龄才开始驯化配合饵料的饵料系列组(A组)的成活率高.初孵仔鱼至变态伏底时A、B组的成活率分别为58.9%和88.7%,从变态伏底始至出苗时全长平均为3.84 cm的A、B组幼鱼的成活率分别为79.0%和83.6%,从初孵仔鱼至出苗时的A、B组的总成活率分别为46.5%和72.4%,而两组的生长率差异不大.  相似文献   

2.
研究用3种不同质量浓度梯度(分别为T0组:0 mg/L;T4组:400 mg/L;T8组:800 mg/L)牛磺酸强化的轮虫(Brachionus plica tilis)对3~20日龄的眼斑拟石首鱼(Sciaenops ocella tus)仔鱼的投喂效果.结果表明,T8组的仔鱼平均全长((8.5±0.8)mm)和成活率(70.5%)都明显高于T0组(平均全长:(6.3±1.0)mm;成活率:28.4%)和T4组(平均全长:(7.0±0.8)mm;成活率:27.4%),T0组和T4组之间生长和成活率并无显著差异;T8组仔鱼的耐干露及耐高盐度(65)能力明显比T0组和T4组强,即仔鱼的抗应激能力受轮虫强化剂牛磺酸的质量浓度影响显著(P<0.05).  相似文献   

3.
在广西海洋研究所分别进行室内和室外军曹鱼人工繁育试验。从海南、福建挑选亲鱼并育肥,注射激素使亲鱼产生精、卵,让卵自然受精。室内用网箱流水、黑桶充气和苗池充气等方式孵化受精卵,室外在池塘网箱中孵化受精卵,仔鱼开口后将其从网箱放出。仔鱼开口后及时投喂合适的饵料,培育30d后出苗。结果获得优质受精卵158.5万粒,孵化出仔鱼148.8万尾,孵化率93.8%,室内3种孵化方式中,网箱流水效果较好。室内育苗平均成活率12.61%,室外育苗平均成活率7.52%,室内培育比室外培育的平均成活率高5.08%。  相似文献   

4.
大弹涂鱼仔,稚,幼鱼的发育阶段   总被引:3,自引:2,他引:3  
探讨了大弹涂鱼仔、稚、幼鱼发育时间、个体大小及其主要特征,并研究了其生长环节和生态特性。大弹涂鱼仔鱼系属于混合性营养类型,其混合性营养期亦即孵化后2~4日龄的开口摄食期。培育期间水温27.0~32.1℃,盐度10~26‰,仔鱼前期和仔鱼后期的早中期(孵化出膜至孵化后 27日龄)生长较慢,平均日增长量为 0.186 mm;从仔鱼后期的晚期经稚鱼期到幼鱼早期(孵化后 27~42日龄)生长较快,平均日增长量为 0.887 mm。稚鱼期生长速度比仔鱼期快,为异速生长。  相似文献   

5.
在水温为21.0~23.7 ℃,盐度为33.5的条件下,用约7.8×105粒受精卵孵出仔鱼约55万尾,孵化率达70 %左右,再经过79 d的培育,培育出幼鱼2.287×105尾,成活率达到41.5 %.初孵仔鱼平均全长(3.16±0.22)mm;初孵仔鱼至孵化后3日龄为前期仔鱼,冠状幼鳍形成,大部分仔鱼已开口,逐渐建立...  相似文献   

6.
鮸状黄姑鱼人工繁殖与育苗技术的研究   总被引:8,自引:0,他引:8  
鮸状黄姑鱼人工繁殖与育苗技术的研究表明:在网箱内培育3龄以上的亲鱼经激素诱导后可在网箱内自然产卵;催产激素LHRH-A和HCG,催产率达到100%;效应时间公36—40h之内;受精卵在水泥池充气孵化,平均孵化率为85.7%。在水泥池培育仔鱼的平均成活率为52%-75%,培育稚鱼的成活率为35%-45%,培育幼鱼的成活率为11%:使用土池培育早期仔鱼,15d仔鱼,22d稚鱼和27d稚色的成活率分别为8%,19%,30%和45%。在盐度30、水温24.2℃的条件下,从受精卵到孵化出苗需要23h30min,在试验期间海水盐度为20-34,水温18—28℃,DO6.5mg/L以上,pH值为8—8.5。  相似文献   

7.
大弹涂鱼人工繁殖和仔稚鱼培育研究   总被引:12,自引:4,他引:12  
本文报道了大弹涂鱼诱导产卵和仔稚鱼培育的结果.亲鱼在生殖季节(5-9月)用HCG或HCG和LHRH-A混合激素催产.受精卵在水温26.5—29℃(不超过30℃),盐度25-27‰的条件下发育,经历87h孵出仔鱼,孵化率60-80%.仔鱼放养在模拟潮间带生态系的水泥池中,投喂动植物性饵料,第五天开始摄食微型浮游生物,第八天进入稚鱼期,开始摄食轮虫和桡足类幼体,第三十三天达到幼鱼期,成活率为37.5-60%.  相似文献   

8.
为确定半刺厚唇鱼(Acrossocheilius hemispinus)仔鱼的饥饿耐受能力及死亡不可逆点(PNR),采用实验生态学方法研究了饥饿对半刺厚唇鱼仔鱼摄食、生长、存活及发育的影响.结果表明,在(26.5±3)℃的水温条件下:半刺厚唇鱼仔鱼在5 日龄卵黄囊消失并开口摄食,其基本不经历混合营养期,属于极易遭受饥饿胁迫鱼类;仔鱼最高初次摄食率出现在6 ~11 日龄,初次摄食期仔鱼的PNR发生在孵化后第15 d,仔鱼具有摄食能力的时间长达11 d,在到达PNR后部分仔鱼仍能存活3 ~4 d,其耐受饥饿的能力较强;9 日龄饥饿仔鱼全长出现负增长,17 日龄绝大多数个体因饥饿而死亡;仔鱼在PNR期未出现“胸角”,而鳔后室萎缩明显和第六条黑色素纵带发育显著滞后可作为鉴别半刺厚唇鱼饥饿仔鱼的重要特征.  相似文献   

9.
耐温牙鲆分子标记辅助选育研究   总被引:2,自引:0,他引:2  
应用分子标记进行耐温牙鲆的辅助选育.首先应用已知的与耐温性为极显著负相关的牙鲆微卫星引物Po42对50尾牙鲆亲鱼DNA进行PCR分析,根据PCR分析结果将其分成耐温组和非耐温组.经过人工催产,耐温组的产卵量明显大于非耐温组和对照组.耐温组繁育的子代仔鱼变态率明显比非耐温组和对照组子代高.在人工增温的条件下,耐温组仔鱼成活率比非耐温组和对照组的仔鱼显著提高.本研究结果证明,牙鲆微卫星引物Po42可用于耐温牙鲆的分子标记辅助选育,同时也进一步确认其与牙鲆耐温性状具有关联性.  相似文献   

10.
鱼类早期生活史的营养与摄食   总被引:2,自引:0,他引:2  
鱼类早期生活史可划分为胚胎期、仔鱼期和稚鱼期,其营养包括内源性、外源性和混合性三种类型。仔鱼必须在卵黄耗尽前的短时间内建立起外源性摄食,否则,便进入饥饿期。仔鱼的初次摄食率和摄食强度均取决于仔鱼的摄食效率,并随着日龄的增加而增加。摄食节律主要受光照强度的影响。仔鱼对饵料的选择随着日龄的增加而变化,同时与饵料的大小、种类、密度等因素有关。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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