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1.
2011年4~5月,研究了温度对花斑副沙鳅(Parabotia fasciata)早期仔鱼的发育、初次摄食时间、群体摄食率及不可逆点(PNR)的影响。结果发现,花斑副沙鳅仔鱼出膜后2 d已开始摄食;初次群体摄食率最高值出现在卵黄囊耗尽后的1~2 d,花斑副沙鳅仔鱼的摄食强度随温度升高而增大。仔鱼抵达PNR的时间随温度升高而缩短:22℃时,仔鱼的PNR出现在出膜后的8.0~9.0 d;26℃时,PNR为7.0 d;28℃时,PNR为5.5 d;30℃时,PNR为5.0 d。最大初次摄食率至PNR之间为不可逆饥饿期,22℃时为3.5 d,30℃时仅为1.5 d,说明温度越高,仔鱼耐受饥饿的能力越差,越不利于仔鱼的存活。研究认为,温度对花斑副沙鳅仔鱼发育、摄食及不可逆点的影响较大;在苗种培育过程中,应根据温度确定投饵时间,适时投饵对仔鱼的成活显得尤其重要。  相似文献   

2.
以人工繁育的俄罗斯鲟仔鱼为对象,采用实验生态学方法,研究了初次摄食时间对生长及存活的影响。结果表明:在水温17.4 ℃下,仔鱼在9~10日龄初次摄食,初次摄食前投喂对俄罗斯鲟仔鱼的生长和存活无显著性影响,延迟2 d以上初次摄食对生长影响明显,存活率在18日龄初次摄食时显著下降,24日龄时饥饿仔鱼全部死亡;23~24日龄时仔鱼如不能建立外源营养即达到饥饿不可逆点(PNR)。人工养殖条件下,俄罗斯鲟仔鱼必须在初次摄食后14 d内建立起主动摄食能力才能保证其仔鱼的正常发育、生长和存活。  相似文献   

3.
稀有鮈鲫仔鱼的摄食和耐饥饿能力   总被引:10,自引:2,他引:8  
研究了室养条件下稀有的鮈鲫的摄食和耐饥饿能力。结果表明,仔鱼一般在孵出后1.5d-2d开口摄食,此时卵黄囊容量约从初孵时的0.1降至0.03mm~3以下,在其后1-1.5d卵黄物质消耗殆尽;饥饿仔鱼的初次摄食率变化型式为:开始较低,然后迅速升高,约在卵黄吸尽时达到最高,最高初次摄食率为100%,保持在80%以上的时间为5d;持续饥饿或延迟开始摄食时间对仔鱼的生长、发育、存活有深刻的影响,饥饿仔鱼全长负生长及饥饿体征明显;初孵仔鱼持续饥饿8-10d达不可逆点(PNR),饥饿仔鱼在PNR前1.5d时存活率低于50%,在PNR后2d全部死亡。  相似文献   

4.
太平洋鳕仔鱼饥饿实验及不可逆生长点的确定   总被引:2,自引:0,他引:2  
李艳秋  姜志强  孙阳  毛明光  孟祥科 《生态学报》2014,34(14):3873-3878
通过研究饥饿胁迫对太平洋鳕仔鱼生长、形态和行为的影响,确定太平洋鳕仔鱼最佳投饵时间及不可逆点,以期为太平洋鳕人工育苗提供科学参考。实验设饥饿组和摄食组进行研究。结果表明,在水温10.0—11.0℃时,太平洋鳕仔鱼在孵化后第5天开始摄食,此时卵黄囊容量约从初孵时的0.2402mm3降至0.0062mm3,卵黄囊体积随仔鱼生长逐渐变小。从第8日龄开始,饥饿仔鱼的全长、体长、肛前长、体高等指标与摄食组差异极显著(P0.01),多项生长指标出现负增长,饥饿组与摄食组仔鱼开鳔率及鳔体积差异明显,表明饥饿对仔鱼生长发育起延迟作用。太平洋鳕仔鱼初次摄食率为30%,第7天初次摄食率达90%,仅保持1d。太平洋鳕仔鱼的耐饥饿能力较差,PNR为9日龄。最佳投饵时间为5—7日龄。  相似文献   

5.
沙氏下鱵鱼仔鱼的摄食能力和营养代谢   总被引:4,自引:0,他引:4  
20 0 0年 6月 18日 14 :2 0时在 35°0 0′N、 12 1°0 0′E海域利用大型浮游生物网采集了大量的沙氏下鱼天然受精卵 ,将受精卵置于新鲜的海水中进行人工孵化 ,7月 1日 8时仔鱼开始孵出 ,0 5h后收集大约 5 0 0尾初孵仔鱼条进行饥饿试验。在培养水温为 2 4 2~ 2 4 8℃条件下 ,沙氏下鱼仔鱼孵化后 1h就建立起巡游模式 ,4h就具有非常高的初次摄食率和摄食强度 ,仔鱼的混合营养期为 2d ,具有初次摄食能力的时间为 3d ,饥饿不可逆转点发生在孵化后大约 3 5d ,不可逆点 (PNR)期仔鱼没有出现胸角这一形态学特征。沙氏下鱼仔鱼这么短的时间建立巡游模式 ,对仔鱼在混合营养期这一有限的时间内顺利地建立起外源性摄食关系 ,在时间上取得了一定的保障作用 ,对种群的繁衍策略具有一定的生态学意义 ,说明在仔鱼的初次摄食阶段 ,自然海区中适合于仔鱼摄食的饵料生物的种类、分布与数量对其早期的成活是至关重要的。PNR期仔鱼是否具有胸角以及胸角是否为仔鱼的饥饿体征因种而异 ,在渔业资源生态调查的仔鱼样品的鉴别工作中 ,应用仔鱼的胸角鉴别健康仔鱼和饥饿仔鱼时应因种而论.  相似文献   

6.
采用软骨-硬骨双染色方法, 对大泷六线鱼仔稚鱼头部骨骼的发育过程进行详细观察与分析。结果显示: 大泷六线鱼初孵仔鱼头部已存在迈克尔氏软骨、腭方骨、舌棒骨和第一基舌软骨等骨骼元件; 当仔鱼4 DPH时, 第二基鳃软骨出现在第一基鳃软骨后端, 缘带向后延伸, 且软骨桥出现, 将头盖骨分为前卤和后卤; 9 DPH时, 3对鳃下骨, 第五对角腮骨可见; 13 DPH时, 迈克尔氏软骨背中部突, 4对鳃上骨、鼻骨、中筛板和侧筛板相继出现; 16—21 DPH时, 基舌骨出现在第一基鳃软骨前方; 23 DPH时, 齿骨开始骨化; 26 DPH时, 前颌骨和上颌骨开始骨化; 至35 DPH时, 前颌骨和上颌骨完成骨化; 50 DPH时, 副蝶骨、前鳃盖骨、缘带、后翼骨、鼻骨和续骨完成骨化; 60 DPH时, 大泷六线鱼头部骨骼, 除舌棒骨外, 基本骨化完成。研究摸清了大泷六线鱼仔稚鱼头部骨骼不同骨元件的发育时序, 阐释了头部骨骼的发育规律及其特殊性, 为大泷六线鱼早期骨骼功能发育研究及头部骨骼畸形鉴定提供了科学依据。  相似文献   

7.
沙氏下(鱼*)鱼仔鱼的摄食能力和营养代谢   总被引:8,自引:0,他引:8  
2000年6月18日14:20时在35°00′N、121°00′E海域利用大型浮游生物网采集了大量的沙氏下(鱼*)鱼天然受精卵,将受精卵置于新鲜的海水中进行人工孵化,7月1日8时仔鱼开始孵出,0.5 h后收集大约500尾初孵仔鱼条进行饥饿试验.在培养水温为24.2~24.8℃条件下,沙氏下(鱼*)鱼仔鱼孵化后1 h就建立起巡游模式,4 h就具有非常高的初次摄食率和摄食强度,仔鱼的混合营养期为2 d,具有初次摄食能力的时间为3 d,饥饿不可逆转点发生在孵化后大约3.5 d,不可逆点(PNR)期仔鱼没有出现胸角这一形态学特征.沙氏下(鱼*)鱼仔鱼这么短的时间建立巡游模式,对仔鱼在混合营养期这一有限的时间内顺利地建立起外源性摄食关系,在时间上取得了一定的保障作用,对种群的繁衍策略具有一定的生态学意义,说明在仔鱼的初次摄食阶段,自然海区中适合于仔鱼摄食的饵料生物的种类、分布与数量对其早期的成活是至关重要的.PNR期仔鱼是否具有胸角以及胸角是否为仔鱼的饥饿体征因种而异,在渔业资源生态调查的仔鱼样品的鉴别工作中,应用仔鱼的胸角鉴别健康仔鱼和饥饿仔鱼时应因种而论[动物学报 49(4):466~472,2003].  相似文献   

8.
饥饿对食蚊鱼仔鱼摄食、生长和形态的影响   总被引:6,自引:0,他引:6  
本文研究了饥饿胁迫下食蚊鱼仔鱼的摄食、生长和外部形态的变化规律.结果表明,在水温(28.5±1.2)℃时,仔鱼产出2h后鳔完成充气即建立巡游模式并开始觅食,摄食比率迅速达到100%,其混合营养期仅有4h.实验期间,投喂组仔鱼的摄食比率一直保持在100%;饥饿组仔鱼在饥饿0-3d内初次摄食比率同样可达到或接近100%,但第4天开始下降,第6天初次摄食比率降至0,抵达饥饿不可逆点(PNR)时间为产出后第5.5天左右.投喂组初产仔鱼对1-2龄期库蚊幼虫的摄食强度为(2.9±1.4)ind/individual·h,摄食强度随日龄显著增长;饥饿组仔鱼在饥饿0-5d内其初次摄食强度也随日龄及饥饿时间的延长显著增长,但均显著低于相应日龄的投喂组仔鱼,其初次摄食比率与初次摄食强度之间并无显著相关关系.饥饿仔鱼在PNR前约1.5d时其累计死亡率已超半数,达(64.4±18.1)%,抵达PNR后数小时内残存个体全部死亡.实验结束(6d)时投喂组仔鱼5项生长指标呈不等速增长,其中体重增长最为显著,瞬时增长率达0.0275/d,此时腹鳍发育基本完备,进入幼鱼期.而同期饥饿组仔鱼形态发育停滞,多项生长指标出现负增长,其中体高负增长最为明显,其瞬时增长率为-0.0511/d;体重次之,体长负增长则不甚明显.饥饿仔鱼在接近或处在PNR期时腹部萎缩呈弧形,体长/体高>5,而同期投喂组仔鱼体长/体高<4.5,两者差异显著,可作为鉴别饥饿仔鱼和健康仔鱼较理想的形态数量指标.  相似文献   

9.
水温23±1℃时,对鲇仔鱼自然光照、持续光照和持续黑暗下的日摄食节律研究表明,3种光照周期下,鲇仔鱼有明显的日摄食节律.持续光照与自然光照的日摄食节律基本一致,但持续黑暗与自然光照的日摄食节律不同;鲇仔鱼在自然及持续光照周期下均属典型的夜晚摄食类型,而在持续黑暗周期下不属于此类型;光照周期的改变对鲇仔鱼日摄食率的影响显著(P<0.05).  相似文献   

10.
在人工饲养条件下鲥鱼仔鱼期开口摄食的观察   总被引:3,自引:0,他引:3       下载免费PDF全文
朱成德 《生态学报》1987,7(4):368-375
受精卵孵化后的仔鱼开口摄食阶段是鱼类早期发育的关健时期,经常引起仔鱼的大量死亡,缺乏充足的适口外源性饵料可能是造成死亡的重要原因之一。1982—1983年,利用赣江产卵场人工授精的鲥鱼受精卵在室内孵化环道中孵出的仔鱼,投喂捞取的天然浮游生物饵料进行了仔鲥有关开口摄食方面的观察,其主要结果如下:仔鱼在孵化后2.5—6.5日为开口摄食期,个体全长为4.5—7.4毫米,仔鱼通常残留多少不等的卵黄物质,为混合性开食营养类型;开口摄食期间的饵料以轮虫,桡足类及其幼体(无节幼体与挠足幼体)为主要种类,适口饵料宽度为仔鱼口宽的39—81%左右,约占仔鱼全长比例的1.5—3.8%;肠内一次饵料量为平均体重的6.72%。  相似文献   

11.
云斑尖塘鳢仔鱼摄食节律的研究   总被引:6,自引:0,他引:6  
对自然光照条件下云斑尖塘鳢仔鱼的昼夜摄食节律和在夜间增加不同强度外光源条件下仔鱼的摄食发生率进行了研究。结果表明,云斑尖塘鳢仔鱼具有明显的昼夜摄食节律,晚上摄食发生率显著高于白天,其摄食主要集中在光线较弱的16:00-00:00;5日龄仔鱼在100-500Lx,8同龄和12同龄仔鱼在10~100Lx光照条件下的摄食发生率要明显高于黑暗或更高光照条件下的摄食发生率。  相似文献   

12.
不同光照强度下乌鳢幼鱼的摄食强度及动力学   总被引:10,自引:0,他引:10  
在103-10-3lx光照强度范围内,乌鳢幼鱼对浮游动物的摄食强度随光照强度的减弱而增强,在10-3lx时达最大值;摄食丰在10-3lx时最高,并随时间的延长而显著降低。  相似文献   

13.
The lake herring (Coregonus artedi) is an important coldwater planktivore in the Laurentian Great Lakes and in smaller inland lakes in portions of Canada and the northern United States. Lake herring cruise the pelagia and feed selectively in both gulping and particulate modes. They are visual predators in environments with adequate illumination. Visual predation by fish consists of a series of discrete steps. We studied the first step in the predation sequence, reaction to prey, at light intensities of 2–1500 Lx in a simulated pelagic environment at 10–13°C. We measured lake herring reactive distances, the distance at which a prey item will be detected and attacked, to live Limnocalanus macrurus, a natural prey of lake herring in Lake Superior. We used the reactive distances and associated angles of bearing and elevation, which described the location of the prey relative to the lake herring, to calculate reactive volume. This reactive volume can be envisioned as an irregular sphere surrounding the fish, within which prey are detected and attacked. All of the attacks on prey occurred in the anterior portions of the sagittal and lateral planes of the lake herring, as would be expected for a pelagic, cruising fish. The reactive volume surrounding the lake herring was generally spherical, but was more irregular than the simple spheres, hemispheres, cylinders, cones or other geometries assumed in previous studies. The reactive distances and the reactive volume changed with light intensity and were significantly smaller at 2–10 Lx than at 40–1500 Lx. At 40–1500 Lx, the reactive volume was expanded over that observed at 2–10 Lx laterally and caudally. Collectively our results indicate that lake herring can visually forage most effectively in environments with light levels >10 Lx.  相似文献   

14.
朱瑞艳  林涛 《微生物学通报》2009,36(12):1939-1943
本研究设计了一种2 L分体式管式光合反应器, 并研究了深红红螺菌(Rhodospirillum rubrum)吸氢酶缺失突变株在该反应器中分别利用人工光源(持续光照与光暗交替)和自然光的产氢规律。结果表明在人工光照条件下R. rubrum的产氢可维持5 d, 持续光照和光暗交替条件下(12 h: 12 h)的氢产量可分别达到5752 mL/PBR ± 158 mL/PBR和5012 mL/PBR ± 202 mL/PBR; 自然光条件下, 最适产氢光照强度为30000 Lux~40000 Lux; 在此光照条件下, R. rubrum产氢可维持6 d~ 10 d, 最高氢产量可达到2800 mL/PBR。尽管利用自然光的氢产量比利用人工光源氢产量低, 但是利用自然光的产氢比较经济, 并且该光合产氢系统操作简单, 该工艺有望开发为低成本的光合细菌产氢技术。  相似文献   

15.
Xue S  Su Z  Cong W 《Journal of biotechnology》2011,151(3):271-277
The growth characteristics of microalgae under different light conditions (continuous or intermittent) are essential information for photobioreactor design and operation. In this study, we constructed a thin-layer (10 mm) flat plate photobioreactor device with a light/dark (L/D) alternation system to investigate the growth of Spirulina platensis under two different light regimes: (1) continuous illumination in a wide range of light intensities (1.00-77.16 mW cm−2); (2) intermittent illumination in medium frequency (0.01-20 Hz). Specific growth rate and light efficiency based on biomass production were determined for each round of experiment. Four regions (light limited region, intermediate region, light saturated region and light inhibition region) were recognized according to the results under continuous illumination. Under intermittent illumination, when L/D frequency increased from 0.01 Hz to 20 Hz, specific growth rate and light efficiency were enhanced. However, the enhancement was different, depending on the applied light intensity and light fraction. The higher the light intensity, the greater the enhancement would be when L/D frequency increased from 0.01 Hz to 20 Hz; and the higher the light intensity, the lower the light fractions is needed to maintain light efficiency as high as that under continuous illumination in light limited region.  相似文献   

16.
使用封闭式箱法,对大豆和玉米两种植物在苗期的N2O释放速率日变化及其同光强、气温的相关性进行了研究,同时对遮光、外加碳源和还原力对N2O释放速率的影响进行了分析.结果表明,两种植物苗期N2O释放速率在日间有两个释放高峰,分别出现在10:30和14:30.遮光处理实验结果证明,遮光后植物的N2O释放速率明显增加;相关性分析表明,苗期大豆在光强低于11345Lx时,N2O释放速率与光强呈正相关关系(R^2=0.7332),光强高于11345Lx时,呈负相关关系(R^2=0.7755),而苗期玉米在光强低于20000Lx时,N2O释放速率与光强呈正相关关系(R^2=0.8711),光强高于11345Lx时,呈负相关关系(R^2=0.8972).加入一定量的碳源(葡萄糖),可使遮光植物N2O的释放速率明显下降,由于同化力(NADH)的介入,在一定程度上影响了N2O的排放通量,同样使得N2O的释放量下降.  相似文献   

17.
The objective of this study was to assess effects of different light intensities on shoot growth, root development and allocation of root-borne solutes via the transpiration stream to various shoot parts of young wheat plants (Triticum aestivum L.). Hydroponic culture allowed direct access to the roots and shoots throughout the experiment. Under low light intensity (100?μmol photons m?2?s?1), shoot growth was restricted, less (but larger) leaves were produced at the main shoot and only a few tillers became visible as compared to plants under high light intensity (380?μmol photons m?2?s?1). The root system was indirectly also affected by the illumination of the aerial parts. A larger number of shorter roots were produced under high light leading to a denser root system, while only a small number of longer roots were present under low light. The distribution of 54Mn (xylem-mobile, but essentially phloem-immobile in wheat) from the roots to the shoot lead to the conclusion that light regime strongly influences the distribution of root-borne solutes within the shoots. Labels introduced into the roots may allow a deeper insight into the transfer of solutes from the root system to the various shoot parts under different light regimes.  相似文献   

18.
Short- and long-term responses of the violaxanthin (V) and lutein epoxide (Lx) cycles were studied in two species of Lauraceae: sweet bay laurel (Laurus nobilis L.) and avocado (Persea americana L.). The Lx content exceeded the V content in shade leaves of both species. Both Lx and V were de-epoxidised on illumination, but only V was fully restored by epoxidation in low light. Violaxanthin was preferentially de-epoxidised in low light in L. nobilis. This suggests that Lx accumulates with leaf ageing, partly because its conversion to lutein is limited in shade. After exposure to strong light, shade leaves of avocado readjusted the total pools of alpha- and beta-xanthophyll cycles by de novo synthesis of antheraxanthin, zeaxanthin and lutein. This occurred in parallel with a sustained depression of F(v)/F(m). In Persea indica, a closely related but low Lx species, F(v)/F(m) recovered faster after a similar light treatment, suggesting the involvement of the Lx cycle in sustained energy dissipation. Furthermore, the seasonal correlation between non-reversible Lx and V photoconversions and pre-dawn F(v)/F(m) in sun leaves of sweet bay supported the conclusion that the Lx cycle is involved in a slowly reversible downregulation of photosynthesis analogous to the V cycle.  相似文献   

19.
This study investigated whether changes in illumination modify perception of day and night conditions in a diurnal species, the Indian weaver bird. Birds were initially subjected to a 12-h light:12-h dark regime (12L:12D; L?=?20 lux, D =?0.5 lux). After every 2 wks, the combinations of light illumination in L and D phases were changed as follows: 20:2 lux, 20:5 lux, 20:10 lux, 20:20 lux, 20:100 lux, and 20:200 lux. Finally, birds were released into dim constant light (0.5 lux) for 2 wks to determine the phase and period of the circadian activity rhythm. They were also laparotomized at periodic intervals to examine the effects of the light regimes on the seasonal testicular cycle. All individuals showed a consistently similar response. As evident by the activity pattern under these light regimes, both in total activity during contrasting light phases and during the 2?h in the beginning and end of first light phase, birds interpreted the period of higher light intensity as day, and the period of lower intensity as the night. During the period of similar light intensity, i.e., under LL, birds free-ran with a circadian period (~24?h). In bright LL (20 lux), the activity rhythm was less distinct, but periodogram analysis revealed the circadian period for the group as 24.46?±?0.41?h (mean?±?SE). However, in dim LL at the end of the experiment, all birds exhibited a circadian pattern with average period of 25.52?±?0.70?h. All birds also showed testicular growth and regression during the 16-wks study. It is suggested that weaver birds interpret day and night subjectively based on both the light intensity and contrast between illuminations during two phases over the 24?h. (Author correspondence: )  相似文献   

20.
传统的大田育秧方式容易受到自然条件的影响,如在连续的阴雨天容易导致烂秧,而采用人工可控的工厂化育秧则有助于解决此类问题。LED光源具有光质纯、光效高以及低能耗等优势,是一种有望在工厂化育秧中应用的人工光源。该研究以生长特性差异明显的水稻天优998(籼稻)和圣稻14(粳稻)为材料,在光强为(60±5)μmol·m~-2·s~-1、光周期为12 h·d~-1的条件下,以450、470和490 nm 3个波长的蓝光LED照射天优998和圣稻14秧苗,考察了不同波长蓝光对两个品种的三叶期和五叶期水稻秧苗生长的影响。结果表明:蓝光处理下两个品种、不同秧龄幼苗的壮苗指数、根系活力和根数增加,体内碳、氮代谢活性增强,抗氧化物酶活性也会增加。3个波长的蓝光对两个品种、不同秧龄水稻秧苗生长的影响存在差异,450 nm照射下水稻秧苗的各项生长指标较优,生产上育秧可根据秧龄选择450 nm或490 nm作为独立和组合光源。  相似文献   

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