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为研究不同光照时长对尖吻鲈(Lates calcarifer)消化酶活力的影响,作者采用生物化学方法系统测定不同光周期(光照时长分别为13、16、19和24 h)下,对尖吻鲈仔鱼阶段和稚鱼阶段3种消化酶(胃蛋白酶PP、淀粉酶AMS、脂肪酶LPS)活性变化进行对比研究。结果表明, 16 h光照时长PP的活力最高,过长的光照时长会抑制PP的活性;增加光照时长对AMS的活性有抑制作用,而对于LPS的活性呈现先抑制后促进的现象。在24 h光照时长时LPS活性增加;在19 h光照时长时对PP活性抑制;对淀粉酶影响不明显。16h光照时长能有效提高尖吻鲈仔、稚鱼的生长速度,更长的光照时长反而抑制其生长。研究表明,不同光照周期对尖吻鲈同种消化酶的影响不同;同一光照周期对不同消化酶产生的影响不同;尖吻鲈稚鱼阶段消化酶对光照时长变化的反应小于仔鱼期,适当地延长光照时长有助于提高尖吻鲈的生长速度。研究结果有助于选择特定的光周期促进某消化酶的活性,达到提高对特定营养物质的消化吸收能力,提高生产实践中仔、稚鱼的生长速度。 相似文献
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横带髭鲷(Hapalogenys mucronatus)为我国东南沿海具有良好发展前景的养殖鱼类,目前亟待突破其规模化苗种培育的瓶颈技术问题。为探究横带髭鲷仔鱼发育阶段的摄食和生长特性,采用实验生态学方法,在水温(24±0.2)℃、盐度为26的条件下对饥饿仔鱼形态发育、生长、不可逆点及投喂状态下的摄食节律进行研究。结果表明,孵化出膜后的初孵仔鱼,3日龄开口摄食,进入混合营养期,3日龄卵黄囊消耗完毕,油球于8日龄消耗完全,混合营养期为5d。饥饿组仔鱼全长呈先增长后下降趋势,拐点出现在3日龄,在4日龄有畸形仔鱼出现。饥饿仔鱼初次摄食率为10.12%,最高初次摄食率出现在7日龄,为85.06%;PNR出现在7日龄和8日龄之间,至9日龄全部死亡。早期仔鱼(7日龄)的摄食高峰出现在7:00、11:00和15:00,晚期仔鱼(14日龄)在7:00、11:00、15:00和19:00四个时间段,摄食高峰均出现在白天,属于典型的白天摄食类型,随着仔鱼的生长发育,摄食高峰有所延长。横带髭鲷仔鱼最佳开口摄食时间在3日龄,掌握仔鱼的摄食高峰期,在此时间段驯化配合饲料,对于活体饵料向配合饲料的驯食转化具有重要实践意义。 相似文献
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半滑舌鳎(Cynoglossus semilaevis)早期发育阶段的摄食特性及生长研究 总被引：36，自引：2，他引：36
采用实验生态学方法，研究半滑舌鳎早期发育阶段的摄食特性及生长特性。结果表明，半滑舌鳎初孵仔鱼在23℃水温条件下，2—3日龄开口摄食，开口后投喂轮虫。孵化后12日龄，全长达到8—9mm左右，可摄食卤虫无节幼体。随着仔稚鱼的发育及摄食强度的增强，表现出越来越明显的摄食节律。6日龄仔鱼在24h内均有不同程度的摄食，相对来说9：00、12：00、15：00、18：00为其摄食率的高峰。16日龄稚鱼的摄食节律已出现较明显趋势，9：00、15：00为其摄食率的高峰。26日龄营底栖生活后稚鱼，由浮游生活方式变为底栖生活方式，摄食率的高峰出现在18：00、24：00。半滑舌鳎的捕食能力随其生长逐渐增强，6日龄仔鱼的平均摄食强度在摄食率高峰之后的2—3h内达到最高，出现在12：00、18：00；16日龄稚鱼在10：00—17：00期间平均摄食强度相对较大。26日龄稚鱼，捕食能力明显增强，伴随着摄食率高峰的出现，平均摄食强度也分别在18：00和24：00达到高峰。随着生活方式的转变，半滑舌鳎摄食节律有着明显的变化：早期的浮游生活阶段，以白天摄食为主，摄食高峰出现在白天；营底栖生活阶段半滑舌鳎转为夜间摄食，摄食高峰出现在夜间。半滑舌鳎不同发育阶段的日平均摄食率分别为：6日龄仔鱼65％，16日龄稚鱼39．7％，26日龄稚鱼11％。随着仔稚鱼的发育，个体生长表现出越来越明显的差异。 相似文献
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本实验研究了不同光照强度(0lx、50lx、500lx和2000lx)和不同光照周期(24L:0D、14L:10D、10L:14D和0L:24D)对刺参(Apostichopus ja ponicus)浮游幼体存活、生长、发育及附着变态的影响。结果表明:(1)光照强度和光照周期显著影响刺参幼体的生长(P0.05),幼体在不同光照强度下生长速度的高低顺序为:500lx50lx2000lx0lx,不同光照周期下生长速度的高低顺序为:14L:10D10L:14D24L:0D0L:24D。(2)不同光照强度下,幼体的存活率随光照强度的升高而增大;0L:24D光周期下的幼体存活率显著低于其余3个光周期处理(P0.05)。(3)4种光照强度下,500lx处理组的幼体发育最快,9d时樽形幼体的发生率为30.9%,0lx处理组樽形幼体的发生率仅为5.2%,且致畸率高达17.7%,显著高于其他光照强度处理(P0.05);4种光照周期下,10L:14D光照周期下的幼体发育最快,9d时樽形幼体的发生率为34.8%,显著高于其余光周期处理组(P0.05)。(4)幼体在不同光照强度和光照周期下变态率的大小顺序分别为:50lx500lx2000lx0lx,10L:14D14L:10D24L:0D0L:24D,光照强度与光照周期均显著影响幼体的变态(P0.05)。可见,提供一定的光照对刺参浮游幼体的生长发育更为有利。 相似文献
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刺参对筏式养殖海区生物沉积物清除作用的模拟研究 总被引：3，自引：0，他引：3
室内模拟研究了刺参(Apostichopus japonicus)(湿体质量13.94 g±2.92 g),对养殖海区生物沉积物和海带粉不同配比饵料的摄食、吸收及其生长,评价了刺参对筏式养殖海区生物沉积物的清除作用。实验共设5个饵料配比组,即纯海带(A组),25%沉积物 75%海带(B组),50%沉积物 50%海带(C组),75%沉积物 25%海带(D组)以及纯沉积物(E组)。在海水温度6-16℃条件下,刺参摄食率随沉积物含量的增加明显增大,A组与E组分别出现刺参日摄食率的最小值(0.88%/d)和最大值(9.34%/d);D组刺参日瞬时生长率和对饵料的吸收效率最高,分别为:1.67%/d和48.3%;A组刺参吸收效率虽然较高,但摄食率和瞬时生长率最低;E组刺参的吸收效率出现负值,但刺参生长效果明显。研究结果表明利用刺参清除浅海筏式养殖海区生物沉积物生态效果明显。 相似文献
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全缘马尾藻(Sargassum integerrimum)生殖细胞排放规律及人工促排条件 总被引：1，自引：0，他引：1
在全缘马尾藻生殖细胞同步成熟的基础上,研究了生殖细胞的排放规律以及人工促排的条件。结果表明:(1)在温度(25±0.5)°C,光照强度(3000±100)lx,光照周期12h︰12h[光照(L)︰黑暗(D)],盐度33±0.5,pH值8.2±0.2、静置暂养条件下,雄生殖托排放精子与雌生殖托排放卵细胞基本同步;雌生殖托排放卵细胞集中在夜间,为间断式排卵,完成整个排卵过程约需3d;雌生殖托的排卵量与其重量呈正相关,3d内排出卵细胞(14431±1288)个/g;卵细胞在排出后4h内完成受精,得到受精卵8358±734个/g;雌生殖托表面的"挂卵"量约为10000个/g,受精卵的脱落量与排卵量相关。(2)在光照周期0h:24h(L︰D)、pH值8.2培养条件的基础上,最适生殖细胞促排条件分别为温度31°C,盐度33±1,水流速度(6±1)cm/s,在该条件下得到的脱落受精卵量最多,所需促排及排放时间最短。在最适条件下,将雌、雄生殖托混合的重量比例改变为1︰6,受精率可提高至(94.4±0.3)%,相比暂养条件下的排卵过程,排卵提前4d,排卵周期缩短2d。 相似文献
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刺参对不同生境中沉积物粒度的选择 总被引：1，自引：0，他引：1
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。 相似文献
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为研究口虾蛄(Oratosquilla oratoria)仔虾在人工养殖条件下的盐度适应性,作者分别实验分析了盐度突变和渐变对其累积存活率、摄食率和掘穴行为的影响。实验结果表明,仔虾盐度耐受能力较强,突变组的仔虾存活盐度为15~45,渐变组的仔虾存活盐度为5~54;仔虾的适宜盐度为21~33,24 h存活率在80%以上;盐度对口虾蛄的摄食影响较大,突变盐度为21~33时,仔虾摄食较为活跃,低于18或高于42基本不摄食;盐度渐变组摄食活跃范围为19~38,低于9或高于50基本不摄食;盐度突变对口虾蛄仔虾掘穴的影响显著,盐度突变至21和33时,掘穴时间极显著延长。本实验结果可以为口虾蛄的人工养殖和增殖放流提供参考和依据。 相似文献
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UV-B辐射对指状许水蚤效应的初步研究 总被引：2，自引：0，他引：2
探讨UV-B辐射增强对海洋生态系统的影响,通过实验生态学的方法,研究了UV-B辐射对指状许水蚤(Schmacheria inopinus,Burckhardt)雌雄成体的致死率、摄食率和滤水率的影响。结果表明,在实验所设定的辐射剂量下,指状许水蚤雄性成体对UV-B辐射的致死率明显高于雌性成体的致死率;UV-B辐射对雄性成体的24h的半数致死剂量(24h.LD50)为5.77kJ/m2,而对雌性成体48h的半数致死剂量(48h.LD50)为5.04kJ/m2。在较低剂量下(0~1.728kJ/m2),UV-B辐射对雌雄成体的摄食率(F)和滤水率(G)都有明显的抑制作用。 相似文献
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经济海藻繁育、养殖及综合利用是海洋农牧业及工业的重要组成部分。20世纪经过几代人的努力，我国在海带、紫菜、裙带菜及龙须菜的繁育、养殖关键技术等方面成功取得突破，为这些海藻的产业化提供坚实的保障，为我国成为世界海藻大国奠定了基础。海藻养殖产业为人们提供了食品、藻胶及其它丰富的产品，这包括保健品、功能食品、化妆品及药物等。海藻养殖产业也对人类经济、社会的发展起到重要作用，通过吸收环境中的二氧化碳、氮和磷，为海洋生态环境的改善发挥了重要作用。本文对我国海藻繁育、养殖及综合开发的历程进行简要回顾，对当前我国、中国科学院海洋研究海藻研究与应用进行了总结，对海藻研究发展的未来进行了展望；适应海藻产业从量向质的方向转变，同时兼顾生态环境效益，为我国海藻研发及应用提供参考。 相似文献
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为探究肿瘤易感基因101(简称TSG101)对斑节对虾(Penaeusmonodon)的免疫应答作用,了解在细菌刺激下斑节对虾的机体发生的变化机制,本研究以哈维弧菌(Vibrioharveyi)和金黄色葡萄球菌(Staphylococcusaureus)为实验组,以磷酸缓冲液(PBS)为对照组,通过荧光定量分析展开对斑节对虾对菌刺激的免疫应答作用。结果显示,斑节对虾的TSG101在各组织中均有表达,在肝胰腺中的表达量最高。在金黄色葡萄球菌刺激下,斑节对虾的TSG101在肝胰腺中的表达量与对照组相比呈极显著上调(P0.01),第12小时的TSG101 mRNA的表达量达到最大(为对照组的21.60倍);在鳃中的表达量与对照组相比呈极显著上调(P0.01),第6小时斑节对虾TSG101的表达量达到最大值(为对照组的3.64倍)。在注射哈维弧菌第9小时,肝胰腺中的PmTSG101 mRNA表达量极显著上调(P0.01)且达到最大(为对照组的2.50倍)。实验结果初步表明,斑节TSG101参与斑节对虾的先天免疫反应,在金黄色葡萄球菌和哈维弧菌的刺激的情况下,该基因RNA水平的表达情况发生明显变化。 相似文献
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向水体中添加不同浓度的短小芽孢杆菌CGMCC1004（Bacillus pumilus）和胶红酵母菌CGMCC1013（Rhodotorula mucilaginosa）以研究凡纳滨对虾（Litoenaeus vapznamei）体长、体质量、存活率、胃蛋白酶、肝胰腺淀粉酶和肝胰腺脂肪酶的影响，以及需钠弧菌（Vibrio natriegens）的感染效果。结果表明：向水体中添加10^4CFU／mL短小芽孢杆菌能提高对虾体长、存活率，但结果不显著，但对体质量增长率具有显著提高作用；水体中添加10^4CFU／mL短小芽孢杆菌对提高需钠弧菌感染后对虾成活率有一定的提高作用；水体中添加10^4CFU／mL短小芽孢杆菌能显著提高胃蛋白酶活性，但是对肝胰腺淀粉酶活性有一定抑制作用；添加复合菌剂比添加单一菌种的作用要好；亦证明了向水体中添加细菌的方式对凡纳滨对虾的体长、体质量、存活率以及水质指标影响比较小，但是对消化酶具有一定的提高作用。 相似文献
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Eight ophiuroid species, six from the northern Kattegat-eastern Skagerrak and three from the northern Adriatic Sea, were examined for regeneration of arms. The species were separated into groups based upon mode of feeding and habitat. Comparison between groups collected in the northern Kattegat-eastern Skagerrak showed that infaunal suspension- and deposit-feeding species (Amphiura filiformis and A. chiajei) had significantly more scars per arm (mean number 0.78) than epibenthic suspension feeders (Ophiothrix fragilis and Ophiocomina nigra, 0.29) or epibenthic carnivores and deposit feeders (Ophiura ophiura and O. albida, 0.13). Spatial variation in arm regeneration incidence was found between sampling sites in the northern Kattegat-eastern Skagerrak for Amphiura filiformis and in the northern Adriatic Sea for Ophiothrix quinquemaculata. The ash-free dry weight (AFDW) and nitrogen (N) contents were measured in arms of six species of brittle-stars from the northern Kattegat-eastern Skagerrak. Differences between species were found, with highest concentrations of AFDW and N in Amphiura filiformis, intermediate in A. chiajei, Ophiocomina nigra and Ophiothrix fragilis, and lowest in Ophiura ophiura and O. albida. As the infaunal suspension- and deposit-feeding brittle-stars (Amphiura spp.) had the highest proportions of damaged arms and highest AFDW and N contents in their arms in this comparison, it is suggested that selective cropping of arms by demersal fish is the main cause of arm damage on Amphiura spp. in this area. 相似文献
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Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning electron microscopy(SEM) and sequence comparisons of two segments of genes(small ribosomal subunit and large subunit of Rubisco), the species were identified as Navicula perminuta, N. pseudacceptata, N. vara, and N. rhynchocephala. Based on phylogenetic analysis and culture trials, there was a close relationship between N. perminuta and N. vara. Growth of these species was evaluated using measurements of optical density at 680 nm(OD680) under various environmental factors. Results showed that the optimum culture conditions were 25℃, 50–100 μmol photons m-2 s-1, pH 8.0, and salinities from 25 to 30. However, the favorable salinity for N. perminuta was surprisingly high at 35. Nutrient requirement analysis demonstrated that growth of Navicula depended on the availability of SiO32-. Their relative growth rates(RGR) peaked at the highest tested level(0.25 mmol/L). The optimal concentrations of NO3- and PO43- were 3.6 mmol/L and 0.18 mmol/L, respectively. Culture of these Navicula species for abalone or sea cucumber aquaculture should take these factors into consideration. 相似文献
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In order to trace their feeding habits, stable carbon and nitrogen isotope ratios (delta15N and delta13C), as well as trace metal concentrations (Zn, Cd, Fe, Cu, Se and Hg) were analysed in the tissues of five commercial shark species from the Celtic Sea: the tope shark Galeorhinus galeus, the black-mouthed catshark Galeus melastomus, the starry smooth hound Mustelus asterias, the spiny dogfish Squalus acanthias and the lesser-spotted dogfish Scyliorhinus canicula. Our results were compared to previously described stomach contents and isotopic composition of potential preys. Isotopic ratio delta15N suggested that tope sharks fed at a higher trophic level (16.7 per thousand in the muscle) than the other species, reflecting its piscivorous diet. The lower values of spiny dogfish (11.6 per thousand in the muscle) might be explained, amongst other things, by either its migratory behaviour or its preference for preys from lower trophic levels. Cd and Hg were correlated with isotopic ratios delta13C and delta15N, and were shown to be diet-related whereas Zn, Fe and Cu seemed much more linked to species-specific metabolism. Although this multidisciplinary approach is revealed as a useful tool for the study of shark ecology, the lack of known trophic fractionation suggests that isotopic data be compared to traditional diet analyses. 相似文献
19.
The aim of the present study was to investigate seasonal and spatial patterns of soil oxygen consumption, nitrification, denitrification and fluxes of dissolved inorganic nitrogen (DIN) in a tidal salt marsh of the Lagoon of Venice, Italy. In the salt marsh, intact soil cores including overlying water were collected monthly at high tide from April to October in salt marsh creeks and in areas covered by the dominant vegetation, Limonium serotinum. In May, cores were also collected in areas with vegetation dominated by Juncus maritimus and Halimione portulacoides. In laboratory incubations at in situ temperature in the dark, flux rates of oxygen and DIN were monitored in the overlying water of the intact cores. 15N-nitrate was added to the overlying water and nitrification and denitrification were measured using isotope-dilution and -pairing techniques. The results show that highest soil oxygen consumption coincided with the highest water temperature in June and July. The highest denitrification rates were recorded in spring and autumn coinciding with the highest nitrate concentrations. Soil oxygen consumption and nitrification rates differed between sampling sites, but denitrification rates were similar among the different vegetation types. The highest rates were recorded in areas covered with L. serotinum. Burrowing soil macrofauna enhanced oxygen consumption, nitrification and denitrification in April and May. The data presented in this study indicate high temporal as well as spatial variations in the flux of oxygen and DIN, and nitrogen transformations in the tidal salt marshes of the Venice lagoon during the growth season. The results identify the salt marshes of the Venice lagoon as being metabolically very active ecosystems with a high capacity to process nitrogen. 相似文献
20.
Vertical and horizontal distribution of meiofauna in mangrove sediments in Transkei, southern Africa
The depth-distribution profiles of meiofauna in four transects in the Mngazana River, Transkei were studied during summer 1980. Highest densities [±1000(100 cm3)−1] were encountered within the top 10 cm of the sediment. Nematodes dominated (80%) and the remainder was made up of ciliates, oligochaetes, gastrotrichs, and low numbers of polychaetes, copepods, kinorhynchs and various crustacean larvae. Among chemical parameters Eh correlated most consistantly with distribution, particularly at the lower tidal levels. Temperature and pH appeared to be of lesser importance. The maximum estimated depth of penetration was on average 72 cm at the HW levels; 32 at MW and 23 at LW. The mean dry biomass was estimated at 1073 mg m−2; 941 mg m−2 and 196 mg m−2 at these tidal levels respectively. The importance of preliminary studies designed to estimate the depth distribution of meiofauna is discussed. 相似文献