紫菜养殖中防治杂藻和病害的新方法（二）

紫菜养殖中，在幼苗期、育苗期以及养成期中，把附着有紫菜的网帘等附着器放在pH为1.0-4．0(用无机酸调节pH值)的处理液中浸泡5—60分钟，再放回海水中继续养殖，就能起到防治杂藻和病害的作用。     

硇洲马尾藻人工育苗常见敌害生物及防治初探

本文调查了硇洲马尾藻人工育苗期间的主要敌害生物,并初步探讨了不同物理方法和化学药剂对其敌害生物的清除效果,旨在为人工育苗栽培提供基础资料。调查发现硅藻、刚毛藻、石莼、浒苔等附生藻类对硇洲马尾藻生长影响较大,蓝子鱼、麦秆虫和藻钩虾的摄食是硇洲马尾藻幼苗海区培育的主要危害。苗帘用5%硫酸铵药浴5min可抑制刚毛藻的生长,以2%柠檬酸药浴5min、0.3%醋酸药浴3min、3%硝酸铵药浴5min等均可药杀石莼、浒苔等附生绿藻,用640mg/L敌百虫浸泡10min可杀灭藻钩虾。     

科技与学术动态

降低海水比重对治疗紫菜丝状体的泥红病效果明显江苏省启东市吕东乡海丰育苗室的高建华等同志在紫菜育苗生产实践中总结出利用降低育苗海水比重的方法治疗紫菜丝状体的泥红病效果明显。他们的具体方法就是将有发病的贝壳用纯淡水浸泡2天,再放入培养池培养,没再有发病。     

河蟹生态育苗技术

河蟹生态育苗的特点即在整个育苗过程不加温，从布苗到大眼幼体不使用抗生素等药物。生态育苗培育的蟹苗体质健壮，生命力强，成活率高，从大眼幼体培育至扣蟹的成活率可达２０％左右。１设施与材料１．１育苗池面积２０～４０m２，水深１m，每单元育苗面积５６０m２。育苗池上方用双层塑料薄膜覆盖，中间内隔３０cm，可起到保温作用。１．２人工配制海水布苗前半个月开始配制人工海水，配制海水用的淡水直接从池塘中打入配水池，不用沉淀和过滤。１．３循环过滤系统由蓄水池、育苗池、排水沟、过滤池组成封闭循环系统。１．４幼体培育的饵…     

条斑紫菜人工育苗期预防绿藻的方法

绿藻是条斑紫菜(Porphyta yezoensis)养殖中的主要灾害之一,它严重地降低了紫菜的产量和品级率。目前,已有晒网、柠檬酸浸泡、冷藏网等多种办法除绿藻,均有一定效果。绿藻污染网帘,一般有三条途径。一是紫菜养成前期海水中的绿藻孢子附着于网帘。二是紫菜网帘上前年残留的绿藻。三是采壳孢子苗时,绿藻孢子与壳孢子同时附着于网帘。因此,预防绿藻的产生应从育苗阶段开始,因为在育苗期,海水和果孢子水中的绿藻孢子亦能钻入贝壳,并可以与条斑紫菜营养藻丝一起生长、发育、成熟、放散,至秋季采苗时与壳孢子同时附着干网帘上,成为海区绿藻难以根除的主要原因。近年来,对条斑紫菜育苗中绿藻的预防进行了许多探索,并取得了一定的成绩,现把行之有效的     

文蛤人工育苗技术研究

文蛤亲贝室内人工暂养促熟后，采用自然排放法、阴干升温刺激法和氨海水浸泡法诱导产卵，以等鞭金藻和扁藻为饵料培育幼虫，以细砂和棕帘为附着基立体采苗，采取室内水池流水培育、定期淘砂筛苗法，经１５６天在６ｍ＾２水池中育出壳长３．４￣５．８ｍｍ的文蛤苗种８５．２万粒，单位面积出苗量达到１４．２万粒／ｍ＾２。     

红鳍东方鲀受精卵孵化育苗关键技术

红鳍东方俗称红鳍、东方、河，因其味道鲜美、营养价值高而在国际市场上颇受欢迎，尤其是日本市场，需求量较大。近几年来，我国人工养殖红鳍东方发展迅速，对苗种的需求量不断上升，因此沿海省份纷纷开展人工育苗，由于我国红鳍东方的自然资源不多，多数单位是从日本等地购入受精卵进行育苗，生产很不稳定。现将红鳍东方受精卵人工育苗的关键技术介绍如下：１ 水质控制 海水水质符合《渔业水质标准》，取水区滩涂面积少，海水交换量大，海水比重１．０１５～１．０２５ｐＨ值７．５～８．５。前期育苗用海水需经完全沙滤后使用。２ 受精卵…     

不同光质及胁迫处理对鼠尾藻及附生藻类光合生理的影响

利用鼠尾藻(Sargassun thumbergii)、菱形藻(Nitzschia)、石莼(Ulue pertusa)和绢丝藻(Callithamnion corymbosum)作为研究对象,通过白光、蓝光、红光照射,1%硝酸铵、1%柠檬酸、3%硫酸铵处理不同时间,淡水浸泡不同时间3种杂藻清除方法,系统研究光质、药物和淡水处理对鼠尾藻及杂藻光合生理的影响。结果显示,对于相对生长速率(RGR)、表观光合速率(Pn)及表观光合速率与呼吸耗氧速率(R)的比(Pn/R),鼠尾藻幼孢子体在蓝光下均明显大于在白光和红光下,而菱形藻则在红光下较大,且鼠尾藻幼孢子体与菱形藻在蓝光下的Pn比明显大于其在白光和红光下的Pn比。结果显示,鼠尾藻幼孢子体若与菱形藻进行竞争,在蓝光下相对于在白光和红光下更有优势。硝酸铵、硫酸铵、柠檬酸药物处理对鼠尾藻幼孢子体的生理状态有一定的影响,且这种伤害具有不可逆性;对鼠尾藻嫩芽的伤害较小,且可恢复正常;对石莼的清除效果不明显,对绢丝藻有伤害。淡水处理对鼠尾藻幼孢子体有伤害,对鼠尾藻嫩芽伤害较小,对石莼影响不大,对绢丝藻有伤害。研究表明,在鼠尾藻幼苗早期培育过程中,可增大蓝光的照射或减少红光的照射,在一定程度上能促进鼠尾藻的生长且抑制菱形藻的生长;在鼠尾藻早期幼苗的杂藻清除中,应避免使用1%硝酸铵、1%柠檬酸和3%硫酸铵处理,会对鼠尾藻幼孢子体产生伤害;鼠尾藻育苗早期不宜使用淡水浸泡除去杂藻,鼠尾藻嫩芽每次淡水浸泡30 min,可清除杂藻,且对藻体无伤害。     

益参宝~(TM)海参专用系列饵料使用说明

[稚参配合饵料]适用范围：浮游期结束，上板(附着)后至参苗体长达到1.5cm左右。用法：用适当容器(塑料桶、玻璃钢水槽等)与海水混合浸泡2-3小时，搅匀后，泼洒到苗池中。如参苗较小，浸泡后可用150～200目筛绢过滤，以确保饵料细度。对自备了鲜藻的用户来说，可在磨出的鲜藻浆中掺     

裙带菜常温育苗技术研究

利用对虾育苗空闲设施,进行裙带菜常温育苗,121块苗帘,其中发育较好的36块,中等的75块,较差的10块,最大藻体2.5毫米,平均121株/厘米。     

4-碘苯氧乙酸在海带夏苗培育中的应用

本文报道了4-碘苯氧乙酸(4-IPOAA)在海带夏苗培育中应用的试验结果。4-IPOAA对海带配子体和幼孢子体的生长发育有着明显的影响，高剂量的4-IPOAA(500mg／L)对配子体的发育有明显的抑制作用；解除4-IPOAA对配子体的抑制，配子体在短期内即能正常排卵、排精并受精形成孢子体；低浓度的4-IPOAA（25mg／L以下)能促进幼孢子体的生长。这项试验结果表明，有可能利用4-IPOAA对配子体的抑制特性，来改进目前所采用的低温、自然光条件下培育海带夏苗的工艺。作者建议把海带夏苗培育工艺改为以下步骤：(1)在常温下采苗；(2)在18℃以下水温条件下培育配子体；(3)在配子体成熟前用4-IPOAA处理，使其停止发育，在较高水温(20℃左右)条件下静水培养被抑制的配子体；(4)在计划夏苗出库前40—50天，解除4-IPOAA对配子体的抑制，恢复最适条件下流水培育；(5)肉眼见苗后及时下海暂养。     

野生和养殖牡蛎种群的比较摄食生理研究

１９９５年４～５月在山东省荣成市桑沟湾用模拟现场流水法对该湾野生和养殖太平洋牡垢种群不同大小个体的摄食生理进行了比较研究。实验结果表明，野生和养殖太平洋牡蛎种群在滤水率、选择率和吸收率等方面无明显的差异，但在保留率和摄食率等方面有明显的差异。这说明野生种群能比养殖种群更好地过滤下并摄入海水中的颗粒物。根据实验数据，用计算机模拟得出了野生和养殖牡蛎种群的滤水率与个体体重的关系为：ＦＲω＝２．８８２３Ｗ０．３６４７，Ｒ２＝０．９４２２和ＦＲｃ＝４．０１４４Ｗ０．２６９１，Ｒ２＝０．９０２９。     

不同繁育方式蟹苗对1龄蟹种培育效果的影响

采用♀亲蟹平均规格分别为158.9g、132.8g,♂亲蟹平均规格为180g、150g两种群体繁育的蟹苗培育的1龄蟹种,其群体规格分别为128只/kg、160只/kg。在面积相同、放养密度相同、饲养条件相同的条件下,采用天然海水土池繁育的蟹苗培育的1龄蟹种成活率为5.1%、亩产蟹种8064只;而采用天然海水工厂化繁育的蟹苗,育种成活率为2.24%、亩产蟹种3609只;在蟹苗来源相同、饲养管理相同,培育池面积为19亩的培育池蟹种产量低于面积5亩的池塘。     

Seawater adaptation and growth of post-smolt Atlantic salmon (Salmo salar) of wild and farmed strains

Atlantic salmon smolts (Salmo salar L.) of wild (Namsen) and farmed (AquaGen) strains were transferred to full-strength seawater (33‰) for 0 (initial control group), 0.5, 1, 2, 4, 8, 14, 30, 42 and 60 days at three different temperatures (4.3, 9.4 and 14.3 °C). Freshwater temperature in each tank was adjusted to test conditions 10 days prior to transfer. Physiological adaptation was monitored as changes in plasma growth hormone levels, gill Na⁺,K⁺-ATPase activity, plasma chloride levels and survival in seawater. Overall, smolts from the wild strain were better able to tolerate transfer to seawater than smolts from the hatchery strain. A delay in the osmotic disturbance and a prolonged period of osmotic stress were observed at the low temperature. Circulating GH levels increased transiently in all groups during the first 12–48 h in seawater and long-term GH levels were positively correlated with seawater temperature. Growth rates were influenced by temperature and strain, with the farmed smolts showing a higher growth than the wild smolts. Food Conversion Efficiency (FCE) was higher in smolts from the farmed strain, whereas no differences in daily food consumption were observed. Optimum temperature for FCE was calculated to be 10.5 °C, whereas the optimal temperature for growth in seawater was calculated to be 13.0 °C. We suggest that the observed differences in seawater tolerance, growth and food conversion probably are genetic and may reflect the fact that the hatchery fish have been bred for rapid growth for several generations.     

重金属离子除去装置在中国对虾育苗生产中的应用

自行研制的高分子吸附剂装置，在两处中等规模的中国对虾育苗场进行了应用实验。结果表明，在其他条件一致的情况下，应用装置与使用自然海水育苗对比，卵子的孵化率平均提高１１．８％，无节幼体到蚤状幼体变态率平均提高１０．２％；应用装置与使用ＥＤＴＡ（２．０ｍｇ／Ｌ）比较，卵子的孵化率平均提高７．５％，无节幼体到蚤状幼体的变态率平均提高３．６％。     

条斑紫菜对胶州湾湿地浅海富营养化状况的生物修复效果

对胶州湾湿地海域条斑紫菜Porphyra yezoensis Ueda养殖区水环境进行了现场调查和研究,对紫菜生长吸收N、P营养盐的效果进行了实验研究,在此基础上综合分析了紫菜对富营养化海水的生物修复效果。研究结果表明,条斑紫菜养殖对胶州湾湿地海水中过剩的营养盐有明显的控制作用,养殖区氮、磷营养盐和有机碳含量以及水质营养指数均低于周边对照区。实验条件下,紫菜生长吸收N、P营养盐和降低海水富营养化程度的效果显著。各实验周期水体中的无机氮含量下降幅度为17.15%～21.26%,活性磷酸盐含量下降幅度为55.73%～61.12%,表明紫菜叶状体生长对磷的吸收量明显高于对氮的吸收量。另外,各换水周期实验海水的营养指数值由2.211～2.592降至0.749～0.873,降低幅度为63.32%～69.39%,海水富营养化等级由"中度富营养"降至"贫营养"。根据胶州湾湿地海域的环境条件,通过大规模栽培大型海藻,可大量去除海水中的N、P、C等生源要素,有效降低海水富营养化水平。     

Exterminating Sunamphitoe namhaensis using carbon dioxide in seawater for culturing brown algae Sargassum horneri seedlings

The amphipod Sunamphitoe namhaensis grazes on seedlings of Sargassum horneri in culture. To exterminate S. namhaensis, we immersed them in seawater with dissolved carbon dioxide—a treatment used previously to remove copepods in cultures of abalone and sea cucumber. Experiments were conducted under different CO₂ (aq) concentrations and for different lengths of time. Amphipod mortality was 100% following immersion in CO₂ seawater with a CO₂ (aq) concentration of 26,262 µmol/kg (pH 5.0) for 60 min. When algal seedlings were immersed in CO₂ seawater under these same conditions, their survival rate and growth were not affected.

     

Morphological Traits of Wild and Selected Strains of Cultured Undaria pinnatifida from Galicia (NW Spain)

Wakame, Undaria pinnatifida, is one of the most popular seaweeds used for human consumption in the world. Wakame quality is mainly valued on the basis of its morphological features. Continual inbreeding and directional selection have traditionally been used with economic seaweeds to obtain elite strains with high‐quality forms. In this study, we compared the morphological traits of cultured sporophytes originating from wild and selected strains of U. pinnatifida in Galicia (NW Spain). Seedlings (young sporophytes) of the two strains were cultured at a sheltered site in a coastal bay of Galicia under the same environmental conditions. Sixteen different morphological measurements were taken on cultured sporophytes. We found that the sporophytes of both wild and selected strains were significantly similar in all studied morphological characters. These results suggest that the morphology of cultured strains of U. pinnatifida from Galicia is due to environmental conditions and that specific morphological traits are dependent on the cultivation environment. Consequently, the morphological traits of Galician U. pinnatifida populations are not an important factor in selective breeding for enhanced wakame quality, and hence, for the establishment of a germplasm bank (e.g., gametophyte stocks).     

大型海藻DNA与RNA同步抽提技术比较

海藻含有的多糖、多酚等物质容易与核酸(DNA与RNA)结合形成不溶于水的复合物,干扰了后续的酶反应,制约了海藻核酸抽提。但抽提高质量核酸却是海藻分子生物学研究的第一步,因此比较了2种同步抽提技术对大型海藻DNA与RNA同步抽提的效果。应用TRIZOL法和CTAB+LiCl法同步抽提了3种海藻的DNA与RNA,接着应用紫外吸收、电泳、PCR、RT-PCR和荧光定量RT-PCR等检测核酸质量。结果显示2种方法均能获得较高纯度的总RNA,总RNA质量完全适合后续的反转录等反应;但在DNA抽提方面CTAB+LiCl法能获得更高质量的DNA。CTAB+LiCl法是一项适用于大型海藻的DNA与RNA同步抽提技术。     

Low-Salinity Acclimation of Juvenile Marine Goliath Grouper Epinephelus itajara

The ability of marine goliath grouper to survive in waters of low salinity was investigated by collecting juvenile individuals from the wild in full-strength seawater and either transferring them directly to fresh water or acclimating them over a 96-h period to fresh water. Juvenile goliath grouper (n = 49; mean 23.4 cm SL; SD 4.1; mean 339.1 g; SD 89.3) tolerated transfers from seawater (30 ppt) to freshwater (<1 ppt), and survived thereafter for a period of 28 d in strictly fresh water, with no observed adverse effects. However, the salinity tolerance was influenced by rate of exposure, as no deaths were observed when the fish were given a gradual decrease in salinity, but 60% of the individuals died when transferred abruptly from seawater into fresh water.