单细胞藻类饲养青蛤稚贝的研究

本试验以几种单细胞藻类为饵料,研究青蛤稚贝的生长和成活率。经21天饲养证明,小球藻、扁藻、三角褐指藻、底栖硅藻都是青蛤稚贝的适宜饵料,其成活率均达90％以上,其中又以投喂底栖硅藻生长最快。     

浅谈单细胞藻类的培养及在海水育苗中的不同效果

1种类搭配在育苗生产中,幼体成长的好坏与饵料的营养直接相关。而多种饵料混合投喂是解决营养全面的最佳途径。如鲍的人工育苗中,在提供适量的底栖硅藻的同时,投喂含大量蛋白质的人工合成饵料以促进生长,而人工合成饵料中的相当一部分就是单胞藻,如螺旋藻、海泥中的底栖硅藻等;海参育苗已见的最佳投饵方法就是角毛藻、盐藻混和投喂,尽管使用其一甚至小新月菱形藻也能出苗,但受营养及培养条件(主要是施肥量)的影响,     

怎样提高稚参成活率

１控制培育密度 适宜的培育密度,不仅可提高稚参成活率和参苗质量,而且能加快稚参的生长速度。适宜的密度为０．２～０．４头／ｃｍ２,这个密度再加上管理措施得当,成活率可达５０％以上。２饵料要质好量足 刚变态的稚参,体长在 ０． ２ ｃｍ之前,饵料以底栖硅藻为主,适当投喂海滩表泥及浮泥,增喂一些单细胞藻类沉淀液。稚参体长达到 ０． ２ ｃｍ以后,饵料以鼠尾藻粉为主,日投２～３次,日投量５０～８０Ｘ １０－６。随着体长增长,每 ３～４日加喂一次含蛋白质较高的人工配合饵料。３加强水质管理 采用流水法培育稚参,可保持…     

方格星虫幼体饵料研究

以10种饵料投喂方格星虫幼体进行定性和定量试验,实验用的方格星虫幼体是通过人工催产孵化获得。试验结果表明:9种海产单细胞藻类和面包酵母都是方格星虫幼体的良好饵料,其中以扁藻、等鞭金藻、叉鞭金藻、绿色巴夫藻、牟氏角毛藻和三角褐指藻投喂效果最好,星虫幼体日平均生长率达46～52μm,存活率达80%以上。饵料密度对星虫幼体生长及存活的影响明显。饵料密度过低,星虫幼体生长率和存活率都较低;饵料密度过高时,虽然星虫生长率有所提高,但存活率明显下降。扁藻投喂密度以4000～6000cell ml、金藻、角毛藻密度以15000～20000cell ml为宜。初期幼体投喂金藻和角毛藻时,其生长率大于投喂扁藻的生长率;后期幼体投喂扁藻时,幼体生长率反而大于投喂金藻和角毛藻的生长率。因此,初期幼体宜投喂细胞较小的金藻和角毛藻,后期投喂扁藻。     

缢蛏稚贝饵料和底质的研究

给缢蛏稚贝投以三角褐指藻加钙质角毛藻和叉鞭金藻加钙质角毛藻的饵料效果最佳，稚贝不但生长快(日平均增长壳长82微米)，而且存活率也高(90％)。饵料投放密度为：在培养第1-4天，2．5万个-5万个／毫升；第5-8天，每天增加至10万个／毫升左右；第9天后，可增至20万个／毫升。在稚贝培育初期宜在水底投放细砂或泥质砂，随着稚贝的生长发育，逐渐增加底质中泥土的比例，这样可提高育苗成活率。     

饵料对扁玉螺浮游幼虫存活与生长的影响

采用投喂小球藻、角毛藻、鱼腥藻、螺旋藻以及小球藻和角毛藻5组饵料分别投喂扁玉螺浮游幼虫,每天测定壳宽和存活率,结果表明,8天后,投有角毛藻的2组存活率较高,生长较快。笔者认为,角毛藻是扁玉螺浮游幼虫的适合饵料。     

皱纹盘鲍稚鲍剥离后大量死亡原因研究

针对稚鲍剥离后大量死亡问题，进行稚鲍剥离规格、稚鲍剥离后直接投喂人工合成饵料与继续摄食底栖硅藻的对比试验，结果是：4mm稚鲍剥离死亡率比2mm稚鲍剥离死亡率低得多，稚鲍剥离后投喂人工合成饵料死亡率很高，摄食底栖硅藻，死亡率则很低。     

不同单胞藻饵料培养九孔鲍早期稚贝的研究

以单种培养的6种底栖硅藻和具有底栖习性的亚心形扁藻(Platymoras sp.)为饵料,培养九孔鲍(Haliotis diversi-color supertexta)受精后12 d的早期稚贝并观察其生长和存活,培养期为28 d,目的是筛选能维持早期稚贝高存活率和生长率的藻种。实验结果表明,培养稚贝成活率最高的3个藻种由大到小依次是爪哇曲壳藻亚缢变种(Achnanthes javanica var.)、流水双眉藻(Amphora fluninensis)和亚历山大菱形藻(Nitzschia alexandrina),使稚贝生长最快的3个藻种由大到小依次是流水双眉藻、爪哇曲壳藻亚缢变种和亚历山大菱形藻。研究结果揭示了适宜的底栖硅藻种类对鲍早期稚贝阶段生长和存活的重要性。个体小或者胞外产物量大的藻类很可能对九孔鲍早期稚贝的培养是有利的。     

微藻饵料对紫海胆浮游幼体生长及存活影响的研究

文章采用湛江叉鞭金藻(Dicrateria zhanjiangensis)、纤细角毛藻(Chaetoceros gracilis)、绿色巴夫藻(Pavlova viridis)、扁藻(Platymonas subcordiformis)、小球藻(Chlorella vulgaris)及混合藻(金藻和角毛藻1∶1混合)投喂紫海胆(Anthocidaris crassispina),研究了微藻饵料对紫海胆浮游幼体生长发育的影响。结果表明,不同饵料对紫海胆浮游幼体生长发育的效果有差异,金藻是最佳饵料品种,角毛藻次之,其后分别为巴夫藻、小球藻和混合藻,扁藻不适于作为紫海胆浮游幼体的开口饵料。就饵料种类而言,金藻作为紫海胆浮游幼体饵料的成活率可达(23.12±1.8)%,显著高于其他单胞藻类(P<0.05)。就发育速度而言,以角毛藻和金藻混合喂食的海胆浮游幼体整体发育速度最快,幼体平均体长为(885.25±30.49)μm,显著高于其他5种处理(P<0.05);投喂巴夫藻的浮游幼体前期生长较慢,体长为(337.98±24.56)μm,后期较其他单胞藻类生长快,体长可达(580±32.95)μm,适宜作为紫海胆浮游幼体后期饵料。     

南方紫海胆人工种苗生产技术

本对紫海胆工厂化育苗的主要技术环节以及海胆成熟度鉴别等进行了探讨。2001年4月～6月的生产结果表明：使用0．5mol／LKcl诱导海胆排放。经过人工授精，并进行洗卵措施后，受精卵按1～2个／ml的密度进行孵化。浮游幼体按0．4～0．7只／毫升培育，以牟氏角毛藻为主，单一或混合投喂金藻、扁藻。稚海胆前期以底栖硅藻为食，后期加喂藻浆、江蓠浆或剥离后投喂石莼、江蓠等。如此可达到海胆苗8～10mm，3000粒／m^2的生产水平。整个育苗工艺达到工厂化生产要求。     

青蛤生物学及育苗研究

<正> 青蛤Cyclina sinensin(Gmelin)为亚热带种,是我国南北沿海习见的经济贝类,肉嫩味美,营养丰富。近几年由于生态环境日益破坏,加上人为的滥采酷捕,使青蛤资源急剧下降。为开发利用这一品种,农业部水产司于1987年把青蛤苗种培育作为重点课     

饵料种类、温度和规格对硬壳蛤的同化率的影响

试验结果表明,温度和规格对硬壳蛤同化率的影响不显著(P>0.05);饵料种类对硬壳蛤同化率影响显著(P<0.05).其中小球藻和湛江等鞭金藻的同化率显著高于小新月菱形藻(P<0.05),而小新月菱形藻又显著高于扁藻(P<0.05).     

菲律宾蛤仔幼虫食料和食性的研究

本文叙述了菲律宾蛤仔面盘幼虫初期对饵料大小和活动能力有明显选择性。培养时，能及时投放个体小、幼虫生长快的单胞藻为饵料，可缩短幼虫培养周期和使幼虫变态更一致。试验表明，湛江叉鞭金藻、角毛藻和三角褐指藻是幼虫较理想的饵料。     

Growth of Amazon ornamental fish Nannostomus beckfordi larvae (Steindachner, 1876) submitted to different stocking densities and feeding management in captivity conditions

The study evaluated productive performance of larvae Nannostomus beckfordi submitted to feeding management (Experiment one) and different stock density (Experiment two) in captivity conditions. The first experiment evaluated feeding rate (100 and 200 nauplii of artemia larvae^?1 day^?1) and feeding frequency (2 and 4× per day). Second experiment evaluated different stock density (1, 5, 10, 20, 40 larvae per litre). At the end of 15 days, for both experiment, the survival and productive performance such as total length (TL), final weight (FW), specific development rate (SDR), specific growth rate (SGR), uniformity for weight (UW) uniformity for length (UL) and relative condition factor (Kr) was determined. For the main results, there is no significant difference to the rate and feeding frequency. The stock density has no significant difference for UW, Kr and survival. Nonetheless, a reduction in the TL, FW, SDR, SGR and FW with the increase in density (20 for 40 larvae per litre) was observed. Thus, for this species Nannostomus beckfordi during to initial stage using exogenous feeding, it is recommended 20 larvae per litre fed with 100 nauplii per larvae having two meals per day.     

史氏鲟南移驯养及生物学的研究:Ⅲ.仔鱼的开口摄食

用单一的水蚯蚓、卤虫无节幼体、池塘浮游动物、人工配合饲料投喂及先卤虫无节幼体后人工配合饲料混合投喂等五种方式培育史氏鲟仔鱼。结果为：卤虫无节幼体是史氏鲟最好的开口饵料,可获得高的成活率和生长率;开口摄食后３－５天,即可开始投喂人工饵料进行食性驯化,２０日龄的鱼苗可获得满意的饵料驯化效果。     

Effects of a dry pelleted diet on growth and survival of the Yucatan octopus, Octopus maya

The effect of a dry pelleted diet on growth of the Yucatan octopus (Octopus maya) was determined and compared with crab diet (Callinectes spp). Two groups of 15 wild collected animals were used. Octopuses were placed in isolation, in a flow‐through system composed of 30 circular tanks (80 L), with a bottom of 40 cm in diameter and a water depth of 80 cm. Experiment lasted 40 days, and octopuses were weighed every 10 days to determine growth rates. Octopuses were fed between 7% and 10% body weight (BW) per day, twice a day at 9:00 h and 17:00 h. Uneaten food was removed after 4 h in the tanks and weighed, to determine food ingestion and conversion. No mortality as a result of natural causes was observed. The 15 octopuses fed on frozen crabs and the 15 fed on the artificial diet had similar weights (P > 0.05) at the start of the experiment, of 486.2 ± 214.8 and 472.5 ± 228.3 g, respectively. At the end of the experiment, octopuses fed on frozen crabs weighed 1466.5 ± 484.0 g, and were significantly larger (P < 0.05), than octopuses fed on artificial diets (438.9 ± 202.6 g). Growth rates for the experiment were of 3.3 ± 0.2 and –0.0 ± 0.3% BW per day, for octopuses fed frozen crabs and the artificial diet, respectively. The artificial diet did not promote growth, but animals did not loose weight and more important, ate regularly all the food supplied, with feeding rates higher than reported in the literature for prepared diets. This makes O. maya a good research animal for the development of artificial diets for cephalopods.     

Controlled propagation of the African catfish,Clarias lazera (C. & V.): III. Feeding and growth of fry

The suitability of some common, natural and artificial feedstuffs for the rearing of fry of Clarias lazera (C. & V.) was investigated in 2 experiments.It was found that a dry trout starter, an experimental dry feed and dried inactive yeast were not suitable feeds for rearing C. lazera fry. Neither could ground Clarias fingerlings or frozen zooplankton be used. By contrast, frozen Artemia and especially live Artemia and live zooplankton gave good results. After 4 weeks the fish thus fed had attained an average weight of 0.3 to 1 g and survival ranged from 50 to 96%.Feeding in excess of satiation and feeding 24 h/day gave the fastest growth, although the differences in comparison with feeding Artemia or live zooplankton to satiation 4 times per day were not significant. The specific growth rate (% body weight) of these fish decreased from 68% at the start of the experiment to 9% after 28 days.     

不同藻类及浓度对青蛤滤水率的影响

采用实验生态学方法,在24℃水温下,研究了饵料生物种类及浓度对不同规格青蛤滤水率(FR)的影响。结果表明:(1)青蛤的FR随着体质量的增大而增大,符合幂函数回归关系:FR=0.5725WD0.705 3(R2=0.9987),单位质量的滤水率(FR/WD)随着青蛤规格的增大而减小。(2)FR随着饵料浓度的增大而增大,但当异胶藻浓度达到8×105ind/L时,开始迅速下降。(3)FR受不同饵料种类的影响,青蛤对牟氏角毛藻的平均滤水效果最好,达到0.6左右,滤水效果最差的是异胶藻,平均FR只有0.3左右。