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1.
《海洋湖沼通报》2017,(6)
本文以海大2号长牡蛎新品种为材料,通过强化亲贝金黄壳色选择和人工升温促熟培育,使海大2号长牡蛎亲贝成熟,利用阴干、升温刺激方法诱导产卵;通过控制幼虫密度、投喂新鲜的单胞藻等技术措施,幼虫快速生长发育到眼点幼虫,投放栉孔扇贝壳进行采苗,眼点幼虫的附着变态率达到48%,成功培育出壳高0.5mm以上的壳色金黄稚贝4.68亿粒,单位水体出苗量达到30×10~4粒/m~3。同时进行与普通牡蛎在亲贝促熟培养、幼虫生长发育方面比较实验,海大2号长牡蛎在亲贝促熟培育方面比普通牡蛎发育慢,但幼虫期在生长速度和成活率表现较明显的生长优势和较高的成活率,显示出海大2号长牡蛎新品种生长的优越性。 相似文献
2.
《中国海洋大学学报(自然科学版)》2016,(11)
采用肾上腺素诱导法和先固着后脱基法,研究了熊本牡蛎(Crassostrea sikamea)单体苗种生产技术,确定了单体苗种的最佳生产方法。研究表明:采用肾上腺素诱导法生产单体熊本牡蛎,诱导效果与肾上腺浓度、诱导时间、幼虫密度有关。浓度实验显示,1×10~(-4) mol/L是单体熊本牡蛎最佳诱导浓度;诱导时间实验显示,1h是单体熊本牡蛎最佳诱导时间;密度实验显示,1 000ind/mL是单体熊本牡蛎最佳诱导密度。采用先固着后脱基法生产单体熊本牡蛎,结果显示:灰色聚乙烯波纹板生产单体牡蛎,幼虫易附着,剥离方便,单体率显著高于筛绢网、塑料薄膜、网衣和聚丙烯扁条(P0.05)。经过25天培育,单体稚贝和固着稚贝壳高分别为(1 953±395)和(1 875±660)μm,单体牡蛎游离状态对生长速度无显著影响(P0.05)。研究结果显示,药物诱导法稚贝中间培育需要特殊设施,不利于生产技术推广;以灰色聚乙烯波纹板作为附着基,利用先固着后脱基法生产单体牡蛎,是一种可行的熊本牡蛎单体苗种生产技术。 相似文献
3.
为了优化蛏苗集约化平面流中间培育技术,研究了不同进水流速和苗种规格对缢蛏中间培育效果的影响,并分析了集约化平面流中间培育系统的水质状况。结果显示,不同进水流速对缢蛏稚贝生长影响显著,稚贝生长速率随进水流速增加而增加,但成活率下降。通过流速与成活率和体质量日增生长量的线性回归分析,估算0.163L/s为适宜的进水流速。在适宜流速和相同放苗重量下,大规格苗种(8万粒/kg)生长速度显著高于小规格苗种(18万粒/kg),但因为小规格组放苗数量多,小规格组单位面积质量较其高出23.72%。除低流速组以外,平面流中间培育过程对叶绿素a和铵态氮有良好的去除效果,去除率分别达到36.99%和3.88%以上,这表明平面流集约化中间培育在利用海水池塘水体进行苗种中间培育的同时,也起到了池塘养殖水体的净化作用。综合认为,在养殖密度0.5kg/m^2、流速0.163 L/s的培育条件下,可以保证水体自污染程度较低,缢蛏苗种生长较快,成活率在73.12%以上。 相似文献
4.
为确定长牡蛎新品种"海大1号"苗种繁育的最适环境条件,研究了盐度对其胚胎发育的影响以及盐度、水温对其幼虫生长、存活率和附着率的影响。结果表明:长牡蛎"海大1号"受精卵孵化的最适盐度为30~35,孵化率最高可达90%。幼虫生长的适宜盐度为20~35,最适盐度为20~30;存活的适宜盐度为20~35,最适盐度为20~25;幼虫附着的适宜盐度为20~35,最适盐度为25~30;对长牡蛎"海大1号"幼虫生长、存活、附着的适宜水温分别为为20~30℃、20~25℃、20~30℃,最适水温分别为30、25、30℃,高温35℃时幼虫全部死亡。综上,长牡蛎"海大1号"苗种培育的适宜盐度为20~35,适宜水温为20~25℃。上述结果为长牡蛎"海大1号"规模化苗种繁育提供了重要的基础资料。 相似文献
5.
采用现场测定方法 ,研究了硬壳蛤稚贝野外中间培育的适宜初始规格以及直接底播、袋中加砂底播、袋中加砂笼养和袋中无砂笼养 4种野外培育模式的效果。结果表明 ,硬壳蛤稚贝进行野外中间培育的适宜规格为壳长大于 2— 4mm。在 4种培育模式中 ,直接底播和袋中加砂底播模式效果比较理想。直接底播的稚贝 ( 30 0 0粒 /m2 )经过 2 8天便可由壳长2 .62mm长到 9.47mm ,达到播种规格 ;经过 62天的培育可以长到 1 7.5 1mm ,成活率可达83.3%。利用袋中加砂底播模式培育的稚贝生长速度略低于直接底播的稚贝 ,但成活率略高于直接底播的稚贝 ,可达到 89.8%— 94.5 %。与上述两种培育模式相比 ,袋中加砂笼养和袋中无砂笼养模式培育的稚贝生长速度较慢 ,其中以袋中无砂笼养模式培育的稚贝生长速度最慢 ,成活率最低。在这两种培育模式中 ,下层稚贝生长最慢 ,其次为中层稚贝 ,再次为上层稚贝 相似文献
6.
2004年11月至2005年1月利用涌流装置和浓缩扁藻进行了大獭蛤(Lutraria(Psam-mophila)maxima)稚贝的中间培育实验。实验所采用的涌流流量为500 mL/min,扁藻密度分别为8 870个/mL±512个/mL和3 368个/mL±557个/mL,稚贝的培育密度分别为20 000,35 000,50 000粒/m2。结果表明,过高的扁藻密度不利于大獭蛤稚贝的摄食,并会造成稚贝的死亡。只有在适当的扁藻密度和涌流流量条件下,大獭蛤稚贝才能正常生长。不同的稚贝培育密度对稚贝的生长存在影响,密度越高,生长越慢;水温低于15℃时,稚贝摄食停止,生长缓慢;稚贝在游离状态下与铺沙条件下的生长基本一致。 相似文献
7.
《中国海洋大学学报(自然科学版)》2020,(Z1)
本研究以黄河三角洲近江牡蛎(Crassostrea ariakensis)为材料,从亲贝性腺促熟培养条件和幼虫培育的盐度、密度、附着基等方面对近江牡蛎规模化苗种繁育技术进行探索,开展近江牡蛎苗种规模化人工繁育。研究发现:采用升温促熟的方式进行黄河三角洲近江牡蛎亲贝促熟培养,经过40 d室内培育,性腺发育成熟;以阴干-升温水刺激方式产卵排精,亲贝精卵排放率达到80%以上;盐度20时,近江牡蛎的受精率、卵裂率和孵化率均最高,达到(96.96±1.91)%、(95.93±1.97)%和(95.87±0.92)%,幼虫生长速度最快,存活率最高且显著高于25和30盐度组(P0.05);与初始密度为10 ind/mL相比,初始密度为6和3 ind/mL时幼虫的生长速度和存活率均较高;牡蛎壳稚贝比扇贝壳稚贝的附着密度稍高,但差异不显著(P0.05)。通过幼虫培育,共获得近江牡蛎稚贝1.98亿粒;平均每个培育池附着基12万片,出苗650万粒;单位水体出苗量达到32.5×10~4粒/m~3,达到规模化苗种生产的要求。 相似文献
8.
为探究在南麂海域进行长牡蛎(Crassostrea gigas)筏式笼养的效果,本研究选用“海大系列”长牡蛎新品种(海大1号、海大2号和海大3号),在南麂海域马祖岙海区开展筏式笼养实验。按月份进行周年跟踪测定该海域的环境因子和长牡蛎个体的生长指标。研究表明：南麂海域周年水温变化范围为10.50～28.12℃,盐度平均为29.14,pH平均为7.93;叶绿素a含量为0.42～6.64μg/L,颗粒有机物含量为2.41～11.32 mg/L;海水中氮磷比范围为2.51～39.06。实验结束时,三个品种中,海大1号和海大3号长牡蛎的湿质量显著高于海大2号(P<0.05),壳高无显著性差异(P>0.05),湿质量的特定生长率均在1月最高,肥满度在6月最高。三个品种的湿质量增加量均与水温、盐度和叶绿素a含量呈正相关关系(P<0.05),与铵盐含量呈负相关关系(P<0.05)。Logistic模型对三个品种的湿质量变化曲线拟合效果最好。本研究结果表明,在南麂海域筏式笼养“海大系列”长牡蛎新品种具可行性,其中,海大1号长牡蛎新品种的养殖效果最好。 相似文献
9.
单体全三倍体太平洋牡蛎育苗技术的研究 总被引：2，自引：0，他引：2
本文利用四倍体太平洋牡蛎雄贝与二倍体雌贝杂交生产出的全三倍体牡蛎,幼虫经常规方法培育至60%出现眼点幼虫时,投放聚乙烯塑料纸、废旧筛绢网和聚乙烯波纹板作附着基,经过附着变态后,当达到2～3 mm时,可脱基生产单体牡蛎,也可中间培育至10 mm边脱基边出售到养殖单位进行养殖,采用此法生产的单体牡蛎方法简便,成本低,脱基致残率极低,是一种生产单体牡蛎好方法之一.2005-2006年在50m3水体中生产单体牡蛎1000万粒 (1cm),单位水体出苗量为20万粒/m3. 相似文献
10.
本文研究了小刀蛏(Cultellus attenuatus)室内人工育苗技术。在繁殖季节选择壳长7.5 cm亲贝,采用铺泥沙蓄养培育,以阴干+维生素浸泡刺激法获得精、卵,幼虫培育中人工控制幼虫密度,D形幼虫到壳顶幼虫前期为5～6个/mL,壳顶幼虫后期为1～2个/mL。进行了不同运输方式和不同底质亲贝蓄养比较试验、不同底质附着基采苗方法试验以及稚贝无底质上升流培育和不同盐度培育试验。研究表明,采用铺细沙加冰的运输方法亲贝成活率最高,干露9 h成活率可达90%;以纯海泥底质蓄养的亲贝肥满度和成活率最高;无底质采苗和铺泥采苗对幼虫变态率的影响没有差异;无底质采苗的稚贝,其生长速度明显慢于铺泥采苗;小刀蛏稚贝不宜用上升流进行培育,宜采用铺泥培育的方法;盐度为15时,稚贝培养效果最好,生长速度快、成活率高,盐度为35时培养效果最差。采用上述技术,成功培育出3 mm以上的商品苗2 000万粒,育苗效果显著。 相似文献
11.
近江牡蛎(Crassostrea ariakensis)规模化人工育苗及养成 总被引：1，自引：0，他引：1
近江牡蛎(Crassostreaariakensis)为广温、广盐分布的河口区大型种,曾在中国南北方河口区都有分布。由于近岸河口环境的变化,在中国北方河口区一度难以寻觅,甚至被认为濒临灭绝。利用黄河三角洲区域滨州、东营主要河口近江牡蛎资源,借助南方丰富的淡水资源,在福建宁德迅速开展了近江牡蛎的规模化人工育苗工作,总计获得了1092万粒种苗。在近江牡蛎原产地滨州进行中间培养及海上养成,在长牡蛎主养海区山东乳山进行转场育肥试养并获得初步成功。与同期养殖的长牡蛎相比,近江牡蛎的氨基酸种类及含量无明显差异,且生长速度快,这些特点将有助于推动其成为我国北方沿海的牡蛎养殖新品种。规模化育苗及养殖还有助于降低对野生近江牡蛎资源的采捕需求,对其资源的保护、牡蛎礁的恢复重构能够起到促进作用。 相似文献
12.
Numerical experiments were carried out to evaluate the physical effects of upwelling/downwelling on the suspended sediment
concentration (SSC) on continental shelves. The results show that (1) because the upwelling or downwelling velocity tends
to be of the same order of magnitude as the settling velocity of suspended sediment, various SSC distribution patterns are
possible, depending on the relative importance of the velocities; (2) the presence of upwelling can enhance the SSC; and (3)
in an upwelling/downwelling system, maximum concentrations may be situated in the middle of the water column, if the settling
velocity is larger than the upwelling velocity. Hence, the physical processes associated with upwelling/downwelling are relevant
to the SSC distribution observed over the mud patch near Cheju Island, East China Sea. Furthermore, a qualitative analysis
indicates that the presence of upwelling/downwelling in the overlying water column increases the accumulation rate at the
seabed. 相似文献
13.
Numerical experiments were carried out to evaluate the physical effects of upwelling/downwelling on the suspended sediment concentration (SSC) on continental shelves. The results show that (1) because the upwelling or downwelling velocity tends to be of the same order of magnitude as the settling velocity of suspended sediment, various SSC distribution patterns are possible, depending on the relative importance of the velocities; (2) the presence of upwelling can enhance the SSC; and (3) in an upwelling/downwelling system, maximum concentrations may be situated in the middle of the water column, if the settling velocity is larger than the upwelling velocity. Hence, the physical processes associated with upwelling/downwelling are relevant to the SSC distribution observed over the mud patch near Cheju Island, East China Sea. Furthermore, a qualitative analysis indicates that the presence of upwelling/downwelling in the overlying water column increases the accumulation rate at the seabed. 相似文献
14.
《African Journal of Marine Science》2013,35(3):501-510
Trends in the abundance, size and growth of newly settled pueruli and early juveniles of the rock lobster Jasus lalandii were determined from samples obtained from mesh bags used for oyster mariculture in Saldanha Bay, South Africa. Totals of 3 842 lobster pueruli and 10 158 juveniles were captured between August 2005 and June 2006, and distinct puerulus settlement events were identified in November and January. Juveniles also peaked during these months as well as in March. The size of newly settled pueruli increased significantly between October and March. The carapace length (CL) of pueruli and juveniles overlapped between 8.5 mm (smallest juvenile) and 10.4 mm (largest puerulus), and 50% of pueruli moulted into juveniles by 9.5–9.6 mm CL. There was a size progression in juveniles, with larger individuals in February and March reflecting an accumulation of juveniles from the earlier settlement events. The estimated growth increment from puerulus to first juvenile instar was 0.5–1.5 mm (4.9–16.1%), increasing to 1.4–2.5 mm (14.4–23.3%) for the second instar. Recruitment of J. lalandii pueruli occurred during periods when strong southerly winds prevailed, which results in a general offshore movement of surface waters along the West Coast and upwelling of cold nutrient-rich bottom waters. However, specific settlement events appeared to coincide with a change in wind direction, reduction in upwelling strength and increase in surface water temperatures, implying that larvae may take advantage of landward movements of surface waters during downwelling, or reversal of upwelling, to return them to shallow coastal waters. 相似文献
15.
长牡蛎 （Crassostrea gigas） 是我国重要的海水养殖贝类，近年其大规模死亡现象频繁发生。为了解长牡蛎的免疫基因在季节上的表达模式变化规律及死亡爆发高峰期的水环境情况，在其主养区山东乳山进行了相关研究。分别在 2018 年 1、 3、5—9 月对该地区牡蛎鳃样品做了免疫基因定量分析，在 6、7、9 月对养殖海域的环境因子 （水温、盐度、pH、溶解氧）、各时间点水体里的浮游植物数量及各采样点牡蛎条件指数的变化进行了研究。结果显示，HSP70 在 7 月份高表达，其余 5 个抗性相关基因在 8 月表达水平达到峰值。在测量的三个月中，7 月水温最高，6 月和 9 月水温略低于 7 月，这一结果和表达模式相关。研究表明近岸的藻类丰度更大。因此，温度是影响长牡蛎存活的各环境因子中的主要因素，温度显著影响到体内抗性基因的表达情况并且间接影响到夏季牡蛎的条件指数。 相似文献
16.
Phiros Shah R. Sajeev K. J. Thara Grinson George Muhammad Shafeeque S. Akash 《Marine Geodesy》2019,42(1):64-84
An attempt has been made to develop a holistic understanding of upwelling and downwelling along the south-west coast of India. The main objective was to elucidate the roles of different forcings involved in the vertical motion along this coast. The south-west coast of India was characterized by upwelling during the south-west monsoon (May to September) and by downwelling during the north-east monsoon and winter (November to February). The average vertical velocity calculated along the south-west coast from the vertical shift of the 26?°C isotherm is 0.57?m/day during upwelling and 0.698?m/day during downwelling. It was concluded that upwelling along the south-west coast of India is driven by offshore Ekman transport due to the alongshore wind, Ekman pumping, horizontal divergence of currents and by the propagation of coastally trapped waves. Whereas downwelling along the coast is driven only by convergence of currents and the propagation of coastally trapped Kelvin waves. Along the west coast of India, the downwelling-favorable Kelvin waves come from the equator and upwelling-favorable waves come from the Gulf of Mannar region. 相似文献
17.
《African Journal of Marine Science》2013,35(1):79-92
A simulation model is used to investigate possible ecological effects of up- and downwelling on nitrogen flows through a kelp-bed food web off the Cape Peninsula, South Africa. The model depicts the flow of nitrogen, which is often limiting in marine ecosystems, from kelps, other macrophytes and phytoplankton, through filter-feeders to carnivores, with a feedback loop via faeces and bacteria to detritus and filter-feeders. When modelled as a closed system, bacteria associated with detritus and animal faeces form a large component of the particulate nitrogen available to filter-feeders, and the faeces feedback loop dominates nitrogen flow. When measured rates of water transport are incorporated into the model, bacteria have little opportunity to accumulate before being transported out of the system. Animal faeces and kelp detritus are the dominant filter-feeder food components under upwelling conditions, whereas phytoplankton is the major contributor to particulate organic nitrogen under downwelling conditions. When realistic pulses of upwelling/downwelling derived from wind indices are used as model input, filter-feeders are shown to decline during the summer upwelling season when much potential food is advected out of the system, and they increase during the winter when downwelling conditions are more prevalent, bringing in nitrogen-rich phytoplankton from the blooms developing offshore. 相似文献
18.
A recent one-dimensional numerical model, the so-called GJ model, neglected horizontal advection and diffusion terms and used
vague physical definition for its boundary conditions. An alternative two-dimensional numerical model, which corrects the
GJ model’s deficiencies, is proposed to evaluate the physical effects of upwelling/downwelling on suspended sediment concentration
(SSC) on continental shelves. The general SSC patterns derived from the two models are similar. However, in the case where
settling velocity is larger than the maximum upwelling/downwelling velocity, the GJ model shows a homogeneous distribution
of SSC, whereas the two-dimensional model identifies a distinct maximum SSC in the middle of the water column in combined
upwelling and downwelling systems, and a SSC gradient in upwelling settings. Furthermore, when the maximum upwelling velocity
is larger than the settling velocity, the GJ model shows a maximum SSC at the water surface, whereas the SSC is lower at the
water surface when using the two-dimensional model. 相似文献
19.
牡蛎是近海生态系统的重要成员,也是世界性海洋主养贝类。我国牡蛎养殖历史悠久,但高质牡蛎产品的长期匮乏已成为新形势下产业转型升级的卡点。在国际海鲜市场,高质牡蛎就意味着品质好、品相优。为实现产业高质量发展,研究了中国经济牡蛎物种组成和地理分布;揭示了温度是不同尺度种性形成的重要环境驱动因子之一;构建了首个贝类全基因组序列精细图谱,发现基因组的高变异性和基因家族的特异性扩张是种性形成的重要遗传基础;对全球27个长牡蛎群体487个个体进行全基因组深度重测序,构建了50M级单核苷酸多态(SNP)资源库并制成190k高密度SNP分型芯片。这些资源基因组学(Resourceomics)研究为高质牡蛎创制奠定了基础。其次进一步查清了牡蛎经济性状的遗传力及表型相关性,锚定糖原含量调控的基因组模块区域,建立品质性状基因模块选育技术,育成"海蛎1号"新品种,糖原含量提高25.37%,比传统育种效率提高65.81%,实现了单一营养物质的定向选育,破解了牡蛎肉质改良的世界性难题。所建立的基因模块育种技术使高质牡蛎遗传创制成为可能。在育成新品种的基础上,还利用牡蛎附着变态阶段的生物学特性及上升流和下降流的物理学原理,创新牡蛎单体种苗制备技术,使种苗单体化率提高3倍;建立设施塑形生态育肥技术,通过壳型重塑并结合养殖水层的增肥调控,优型率达92%,出肉率达20%—23%。单体塑形养殖技术使牡蛎品相也达到国际知名品牌的产品标准。团队建立的高质牡蛎创制技术体系在县域规模进行标准化应用示范,支撑了"乳山牡蛎"成为行业第一品牌,产业经济效益提高2—3倍,实现了牡蛎产业从低质低效到高质高效的嬗变,示范带动了中国牡蛎产业的高质量发展。 相似文献
20.
牡蛎的滤食作用不但能控制浮游植物丰度，还能通过摄食选择性影响群落结构。通过在较高营养水体的围隔实验表明，牡蛎养殖在持续磷限制条件下，促使浮游植物群落由甲藻向小型硅藻优势转变。实验结束时对照组中浮游植物群落由扁压原甲藻主导，占总丰度的77%；而牡蛎养殖组新月柱鞘藻丰度占比达到93%。牡蛎养殖组中，甲藻去除速率随养殖密度增长，但是硅藻最终丰度在高密度牡蛎组最高。研究结果说明大量的贝类养殖能够提升小型链状硅藻的优势度，增加此类赤潮发生风险。 相似文献