2种海洋微藻对氮浓度生长响应的研究

以中肋骨条藻和三角褐指藻为试验材料,探讨2种海洋微藻对氮浓度的生长适应性差异。结果发现2种海洋微藻的生长速率显著受氮浓度的影响。试验结束时,氮质量浓度为0.75、7.5、75 mg/L和150 mg/L时,中肋骨条藻的叶绿素荧光值分别为139.5、816.3、881.9μg/L和868.5μg/L;三角褐指藻的叶绿素荧光值分别为54.3、572.9、974.4μg/L和976.4μg/L,说明高质量浓度氮促进海洋微藻增殖,但超出一定的氮质量浓度范围,促进作用不明显。2种海洋微藻对氮质量浓度的生长响应存在显著差异,中肋骨条藻比三角褐指藻更忍耐低氮质量浓度的胁迫。结果证实氮营养在海洋微藻生长繁殖过程中的重要性,不同微藻对氮营养的生长适应性差异是决定微藻在海洋环境中占据优势程度的一个重要因素。     

富含EPA的海洋微藻的规模化生产

单细胞海洋微藻是人类正在开发的具有极大应用价值的生物资源,在微藻代谢产生的诸多化合物中,二十碳五烯酸（EPA,20：5n-3）尤其引起人们的关注。EPA在预防和治疗人类多种疾病（如心血管疾病、癌症和炎症性疾病）方面有显著作用,而且还能起到延缓衰老的生理作用。如今EPA的唯一商业来源是深海鱼油,但由于味道、气味和稳定性等方面的问题,这种资源不尽人意。此外,鱼油中大量的其他多不饱和脂肪酸使得EPA的提纯更为复杂,导致纯品的价格很高。     

辽宁近海外来赤潮海洋微藻入侵现状

<正>外来海洋生物入侵已成为全球性的环境问题之一,而生物入侵对生态系统稳定性的影响以及经济损失,已经引起科学界和社会公众的广泛关注。20世纪及21世纪初运输船舶压舱水排放等导致外来海洋浮游生物广泛传播。本文主要通过收集中国生物多样性数据库、中国外来入侵物种数据库、中国外来海洋生物入侵数据库、全球入侵物种数据库美国海岸警戒压舱水管理项目数据库资料及相关文献,结合辽宁近海历史与近期的调查资料,综     

氯苯对四种海洋生物的急性毒性研究

采用半静水法研究了氯苯对三疣梭子蟹、黄姑鱼、脊尾白虾和菲律宾蛤仔4种海洋生物的急性毒性作用.试验结果表明,在海水pH 7.9～8.2、水温24.1～24.5 ℃、盐度27.8～29.2条件下,氯苯对三疣梭子蟹、黄姑鱼、脊尾白虾和菲律宾蛤仔的96 h LC50分别为52、15、0.39、91 mg/L.综合氯苯对4种海洋生物的毒性机理和急性毒性数据,氯苯对海洋生物的毒性依次为:脊尾白虾>黄姑鱼>三疣梭子蟹>菲律宾蛤仔.氯苯对三疣梭子蟹、黄姑鱼、脊尾白虾和菲律宾蛤仔的安全质量浓度分别为0.52、0.15、0.0039、0.91 mg/L.     

Acute Toxicity of Copper Sulfate and Chelated Copper to Channel Catfish Ictalurus punctatus

Channel catfish fingerlings Ictalurus punctatus were exposed to copper sulfate or a commercial chelated copper product in a series of static toxicity tests conducted using waters with a wide range of total alkalinity and hardness values. Estimates of mean 96 h LC50 values were 0.05, 0.73, 0.95, and 0.98 mg/L as Cu for copper sulfate and 0.06, 1.51, 1.97, and 1.74 mg/L as Cu for the chelated copper product in waters having total alkalinities of 16, 76, 127, and 240 mg/L CaCO₃ respectively. On a copper basis, the chelated product was significantly ( P < 0.05) less toxic to fish than copper sulfate in all waters except that of the lowest total alkalinity. Highly significant ( P < 0.01) linear relationships were found between LC50 values for copper from copper sulfate and pH, log [total alkalinity], and log [total hardness], of test waters. These results cast doubt on the validity of the formula commonly used to calculate practical copper sulfate pond treatment rates, which is based upon a simple linear relationship between application rate and total alkalinity.     

铜和镉对方格星虫的急性毒性研究

在水温26.5~29.5℃下,采用毒理学试验方法,比较研究了Cu2+和Cd2+对平均体质量(10.17±1.15)g的方格星虫急性毒性效应的差异,为进一步评价重金属离子对方格星虫的毒性效应等提供参考。方格星虫于实验室暂养3~4d后,选用健康和规格一致个体进行试验。Cu2+暴露质量浓度设置为0.120、0.125、0.130、0.135、0.140mg/L,Cd2+暴露质量浓度为30、31.180、32.406、33.680、35.004mg/L。由死亡率和试验质量浓度回归分析可见,Cu2+对方格星虫在24、48、72、96h的半致死质量浓度分别为0.180、0.136、0.122、0.118 mg/L,Cd2+对方格星虫在24、48、72、96h的半致死质量浓度分别为45.754、34.471、29.628、24.328mg/L;Cu2+和Cd2+对方格星虫的安全质量浓度分别为0.00118mg/L和0.24328mg/L。     

微藻高密度培养与冷冻保藏的研究进展

微藻作为水产养殖动物的活饵料,在水产养殖育苗中一直有着重要的地位和广泛的应用.传统的饵料藻培养方法存在着生物量低、藻液保藏困难等问题,以至阻碍了其商业化发展.综述了近年来在水产饵料藻高密度培养及冷冻保藏技术领域的研究进展,以期促进国内水产生物饵料产业化的发展.     

海洋微藻全封闭、连续式培养初步试验

采用连续式微藻培养系统(包括封闭式光合反应器和连续式水处理器)对小球藻和新月菱形藻的生长情况进行研究。结果表明：(1)用该技术培养的微藻生长速度快，培养密度大，培养密度可提高3倍以上。常规培养7—8d所达到的生物量在光合反应器中3d即可完成。(2)在连续培养状态下，每日收获1／5藻液，可使反应器内保持较高密度。因此该反应器具有稳定生产微藻能力。     

4种海洋微藻酸性磷酸酶的分离纯化及其性质的研究

提取、纯化了4种海洋徽藻的酸性磷酸酶,确定了酸性磷酸酶的条件并研究其性质.结果显示,在37℃条件下,塔玛亚历山大藻酸性磷酸酶回收得率低,但酶活最高;确定各徽藻酶促反应初速度均恒定的时间为15 min;三角褐指藻、塔胞藻、塔玛亚历山大藻、海链藻的酸性磷酸酶分别在酶浓度为0.96、0.29、0.25、14.9 mg/mL酶促反应速度达最高;三角褐指藻、塔胞藻、海链藻的酸性磷酸酶最适pH值为3,而塔玛亚历山大藻为4;37℃下各藻产生的酸性磷酸酶米氏常数为:塔玛亚历山大藻＜塔胞藻＜三角褐指藻＜海链藻.试验证实,塔玛亚历山大藻在磷源限制条件下,较其他3种海洋徽藻更易于利用有机溶解磷;塔玛亚历山大藻在利用海洋微藻生产酸性磷酸酶方面极具应用前景.     

两种麻醉剂对罗非鱼的急性毒性及联合毒性研究

根据预试验结果确定最高安全浓度和最低全致死浓度,分别设置5个等对数浓度,进行MS-222和苯唑卡因及其1:1混合药物对罗非鱼(Oreochromis niloticus)的24h和96h毒性试验.结果:MS-222对罗非鱼的24h、96h半致死浓度及95%置信区间分别为88.84 mg/L(86.92～90.81 nag,/L)、76.18 mg/L(73.27～79.21 mg/L);苯唑卡因对罗非鱼的24h、96h半致死浓度及95%置信区间分别为44.49 mg/L(43.76～45.24 mg/L)、22.61 mg/L(20.29～25.20 mg/L);混合药物对罗非鱼的24h、96h半致死浓度及95%置信区间分别为63.35 mg/L(61.00～65.79 mg/L)、30.39 mg/L(29.48～31.34 mg/L).这表明:在同等剂量条件下,苯唑卡因对罗非鱼的毒性比MS-222强;将两种药物等比例混合后,在24h和96h毒性试验中,分别呈现出拮抗作用和协同作用.     

2种水产杀虫剂共同使用对南美白对虾的急性毒性试验

通过试验验证在水体中先后施用不同溶度的杀虫剂（阿维菌素和辛硫磷）在48小时内导致南美白对虾的中毒情况和死亡率。2种药物混合使用对南美白对虾的最低致死浓度范围：阿维菌素1．5～2．25×10^-4mg/L＋辛硫磷1．2-1．8×10^-2mgm,不同浓度的杀虫剂对南美白对虾的致死时间随着浓度的增加而缩短。南美白对虾对阿维菌素中毒症状表现为麻痹、昏迷、死亡,辛硫磷中毒症状表现为抽搐、痉挛、死亡。     

铜、锌离子对尾草履虫的急性毒性试验

试验结果表明,随着离子浓度增高,Cu2 、Zn2 对尾草履虫的毒性增大,且呈现出明显的剂量效应关系。回归分析表明,两种离子的概率单位与浓度对数之间存在着极显著的正相关。Cu2 、Zn2 的1 h半致死浓度(LC50)分别为0.32 mg/L、11.48 mg/L,95%置信区间分别为0.29~0.36 mg/L,8.98~14.88 mg/L。Cu2 对尾草履虫的毒性大于Zn2 的毒性;尾草履虫对Cu2 浓度变化比Zn2 更为敏感。     

硫酸铜对栉孔扇贝急性毒性胁迫研究

探讨了硫酸铜对栉孔扇贝的24、48、72、96 h的毒性,并计算出硫酸铜对栉孔扇贝的24、48、72、96 h的半致死质量浓度(LC50)分别为(0.32±0.099)mg/L、(0.112±0.022)mg/L、(0.074±0.005)mg/L、(0.063±0.005)mg/L,安全质量浓度为0.012 mg/L...     

Acute Toxicity of Copper to Juvenile Freshwater Prawns,Macrobrachium rosenbergii

Abstract

Copper sulfate is an algicide that is commonly used for phytoplankton and filamentous algae control and has been used as a therapeutant in aquaculture. The objectives of this study were to determine the acute toxicity of copper sulfate and the safe level for use in freshwater prawn, Macrobrachium rosenbergii, production ponds in a high calcium and alkalinity environment. Six concentrations of copper sulfate (0, 0.2, 0.4, 0.6, 0.8, 1.0 mg/L) were tested in 8-L glass aquaria for 48 hours with three replicate aquaria per treatment. Concentrations of calcium hardness and alkalinity were set at 100 mg/L using calcium chloride and sodium bicarbonate, respectively. After 48 hours, survival of the control treatment (0% CuSO₄) averaged 97%, which was significantly higher (P< 0.05) than that of all other treatments. The survival in the 0.2 mg/L and 0.4 mg/L (70% and 73%, respectively) concentrations of CuSO₄ were significantly greater (P< 0.05) than higher dose treatments; but were not significantly different from each other (P> 0.05). Treatments containing 0.6, 0.8, and 1.0-mg/L copper sulfate demonstrated a dramatic decrease in prawn survival, which averaged 30, 7, and 0%, respectively. Regression analysis of the data predicted 48-hour LC₅₀ for copper sulfate tobe0.46 mg/L. Since recommended application rates for use of copper sulfate as an algicide are 1.0 mg/L or more for water with alkalinities of 100 mg/L, copper sulfate treatments are not recommended for prawn production ponds.     

Toxicity of Chelated Copper to Juvenile Red Drum Sciaenops ocellatus1

Acute toxicity of chelated copper to juvenile red drum (x?= 3.1 g) was determined in a static test at 25 C and 8 ppt salinity. The 12, 24, 48, 72, and 96 h LC₅₀s were 1.90, 0.84, 0.75, 0.64, and 0.52 mg/L copper, respectively. Effects of temperature and salinity on the 96 h LC₅₀ (0.5 mg/L copper) for juvenile red drum (x?= 5.0 g) were tested at two temperatures, 25 and 30 C, and three salinities, 0.5, 8, and 30 ppt. Temperature significantly affected mortality; mortality in 0.5 and 8 ppt salinities was significantly higher at 30 C than at 25 C. An increase in salinity significantly reduced the mortality of juvenile red drum. Total mortality occurred in 0.5 ppt salinity within 48 h at 25 C and within 12 h at 30 C. Total mortality occurred in 8 ppt salinity within 72 h at 25 C and within 48 h at 30 C. No mortality occurred during 96 h in 30 ppt salinity at 25 C or 30 C.     

Potential of New Strains of Marine and Inland Saline-Adapted Microalgae for Aquaculture

Several problems currently limit the reliability of algal cultivation systems for the production of aquaculture feeds. Many of these problems may be eventually solved through research in culture system design and operation. However, research into the isolation and development of new strains of microalgae may also directly lead to improved system performance.
Through a collection and screening program aimed at isolating microalgae tolerant to high light, high salinity, and high temperatures, we have been able to isolate several new strains with enhanced production potential (30-35 g/m²/d). The overall range of environmental tolerance exhibited by these strains may result in enhanced culture stability, leading to the high production rates.
The estimated costs of producing strains with these high production rates range from $1.18 to S1.71 per kg (unharvested), depending on the size of the production system. Total production costs for harvested algae (15% solids algal cell paste) range from $1.63 to $2.45 per kg. The major costs for producing harvested algae include the cost of CO₂, as well as capital and operating costs for the harvesting systems.     

铜对细鳞鲑幼鱼鳃和肝组织的急性毒性

在水温(16±0.5)℃下,采用静水实验法研究不同浓度的铜离子对体质量(35.8±9.6)g的细鳞鲑Brachymystaxlenok幼鱼鳃和肝脏的急性毒性,铜离子浓度为24h半致死浓度(LC_(50))的1/4倍、1/2倍,及1倍。结果表明:铜胁迫初期细鳞鲑幼鱼的鳃充血而颜色而变暗,后期鳃血管和细胞病变,颜色变浅。鳃丝先弯曲,然后溃烂,最后脱落;肝脏出血、肿大,切片显示肝脏细胞空泡化,后期可以看到坏死的细胞核。铜离子对细鳞鲑幼鱼的鳃和肝脏组织有明显的破坏作用,是铜急性中毒致死的原因之一。     

两种药物对脊尾白虾各期(氵蚤）状幼体的毒性试验

采用静水实验法进行甲醛和孔雀石绿对脊尾白虾 (Exopalaemoncarinicauda)各期状幼体 (Z1～Z6)的急性毒性研究。结果表明 :在pH值为 7 9± 0 5、水温 (2 6 0± 0 5 )℃的条件下 ,甲醛对脊尾白虾Z1～Z6的半致死浓度 (48hLC50 )分别为 176× 10 -6,16 7× 10 -6,15 0× 10 -6,16 7× 10 -6,113× 10 -6,5 5× 10 -6,安全浓度 (Cs)分别为 30× 10 -6,17× 10 -6,32× 10 -6,11× 10 -6,4× 10 -6,9× 10 -6;孔雀石绿对脊尾白虾Z1～Z6的 4 8hLC50 分别为 0 4 5 1× 10 -6,0 4 4 8× 10 -6,0 5 91× 10 -6,0 4 4 0× 10 -6,0 380× 10 -6,0 15 8× 10 -6,Cs分别为 0 0 6 9× 10 -6,0 0 5 8× 10 -6,0 10 2× 10 -6,0 0 90× 10 -6,0 0 71× 10 -6,0 0 34× 10 -6。其中Z5和Z6对以上药物的敏感性较高     

Nutritional Properties of the Marine Rotifer Brachionus plicatilis Fed the Freshwater Microalgae Selenastrum capricornutum

This study examined the effects of storage time on the fatty acid composition of freshwater Selenastrum capricornutum algal paste under 4 C refrigeration, the fatty acid composition of rotifers fed the fresh and stored algal paste, and the toxicological properties of the algal paste. Microalgae were produced in a hydraulically integrated serial turbidostat algal reactor (HIS-TAR), harvested as a paste, refrigerated and analyzed every 2 wk. Fresh Selenastrum capricornutum paste had almost three times greater concentration of unsaturated fatty acids than saturated fatty acids. Over 50% of the unsaturated fatty acids were made up of n-3 and n-6 fatty acids. Total unsaturated, n-3 group and n-6 group fatty acids decreased ( P 0.05) during storage, including the nutritionally important fatty acids (C20:4n6, C20:5n3, C22: 6n3). Rotifers fed 2– and 4-wk-old algal paste had a significantly lower ( P 0.05) total unsaturated fatty acid percentage and significantly greater ( P 0.05) total saturated fatty acids than those fed fresh algae. There were no significant changes in the n-6 group fatty acid level in the 4-wk-old paste feeding study or for the n-3 or n-6 groups in the 2-wk-old paste feeding study as compared to fresh algae. The levels of the three nutritionally important fatty acids (C20:4n6, C20:5n3, C22:6n3) did not differ between rotifers fed fresh and stored algae. Stored algae did not present toxicity to rotifers and Daphnia at the normal feeding concentration. These results indicated that the use of refrigerated freshwater algal paste for production of rotifers results in live feed with adequate nutritional properties for marine larviculture. This could eliminate the costs associated with production of marine algae, which could be replaced with freshwater algae, and may provide an alternative to cryopreservation.