“鱼虾可乐”对罗氏沼虾育苗水质和效果的影响

为加快水质培育速度,促进藻类快速繁殖,利用藻类降解有害物质,增强水体的自净能力,为幼体提供良好的生态环境,以提高罗氏沼虾育苗成活率[1],我们进行了"鱼虾可乐"对水质和育苗效果的影响试验,对照组不投放"鱼虾可乐"。在相同的技术管理条件下进行罗氏沼虾育苗试验,试验过程中注意观察育苗水体浮游生物的变化情况,定期检测水体中的有害物质的浓度,育苗结束时计算育苗成活率,通过水质培育效果和育苗效果来评估"鱼虾可乐"在罗氏沼虾育苗中的效果。结果显示:试验组水体中氨氮含量降低19.76%,亚硝酸氮含量降低21.43%,溶解氧提高11.93%,有效改善了育苗水质,为幼体生长和活动提供比较稳定的生态环境,使育苗成活率提高了11.29%。表明:"鱼虾可乐"能缩短育苗水质培育时间,有效改善育苗水体环境,是一种营养型水质改良剂。     

云龙湖水库沉水植物净化水质的原位围隔试验

在富营养化水库-----云龙湖水库中建立小型围隔区, 对4种沉水植物及组合进行了净化水质的现场试验研究。沉水植物恢复后, 能够有效提高水体的透明度, 改善水体的溶解氧状况, 对水体中的TN和CODC r、BOD5 有明显的去除作用。在受试的沉水植物中, 狐尾藻对水体透明度的改善效果最好, 金鱼藻对水体的增氧效果最好,苦草对总氮的吸收作用最明显, 狐尾藻去磷效果最好, 狐尾藻和金鱼藻对有机质的去除效果较好, 且不同种类组合具有一定的协同作用。     

云龙湖水库沉水植物净化水质的原位围隔试验

在富营养化水库--云龙湖水库中建立小型围隔区,对4种沉水植物及组合进行了净化水质的现场试验研究.沉水植物恢复后,能够有效提高水体的透明度,改善水体的溶解氧状况,对水体中的TN和CODcr、BOD5有明显的去除作用.在受试的沉水植物中,狐尾藻对水体透明度的改善效果最好,金鱼藻对水体的增氧效果最好,苦草对总氮的吸收作用最明显,狐尾藻去磷效果最好,狐尾藻和金鱼藻埘有机质的左除效果较好,且不同种类组合具有一定的协同作用.     

"解毒净水宝"在水质改良中的应用

"解毒净水宝"为我公司自主合成的水质改良剂,主要通过络合、吸附、转化等多种形式快速降低水体中的重金属、氨氮、硫化氢、余氯及一些残留农药浓度,净水效果十分明显,对重金属的络合能力远高于EDTA,可有效改善鱼虾生长的水体环境,预防水质恶化、药物中毒或暴发性疾病.     

弹性立体填料在水产养殖中的应用研究

为探索弹性立体填料原位使用对水产养殖过程中水质及动物生长的影响。通过在室内3．0 m3的小型养殖池中分别按0 m/ m3（ A组）、0．5 m/ m3（ B组）、1．0 m/ m3（ C组）及3．0 m/ m3（ D组）的使用量挂设弹性立体填料,每组设3个平行。通过定期检测水体中无机氮及碱度含量来评估其对水质的影响,并统计试验结束后的投喂量及增重量,评估其对养殖动物生长的影响。结果表明,弹性立体填料能够有效降低养殖水体中的氨氮、亚硝酸盐氮含量,提高养殖水体硝酸盐氮含量和幅度与弹性立体填料使用量呈正比关系,明显降低水体中的总碱度,并表现为随填料安装密度增加水体总碱度下降速度加快,可以促进养殖动物增重,具有降低饵料系数的趋势。     

去除鱼类土腥味养殖系统的构建技术研究

以团头鲂、鲫鱼为试验对象,构建了一种基于人工生态系统的循环水养殖系统。通过底层陶粒吸附细菌、流水养鱼加快鱼类的代谢、湿地去除氨氮提高鱼的活性、生化箱培养硝化菌和反硝化菌来调控水质并起到控制水流速度的作用等技术手段来去除鱼类土腥味,同时研究不同盐度对其调控效果的影响。结果表明:本养殖系统对水体中的藻类和放线菌以及鱼体中的放线菌有明显的抑制作用。把(土池)池塘内养殖的鱼放入系统中暂养,一个月后土腥味显著降低,3个月后土腥味几乎消失;且随着水体盐度的升高,效果越加明显。     

生物水净化剂对养殖池塘水质的调控作用初探

生物水净化剂是含有芽孢杆菌、酶和营养物质的一种微生态制剂。可以用于集约化水产养殖的各个环节和其它水处理过程。进行了3种不同浓度(2、4、8g／m^3)的生物水净化剂30d的试验。结果表明。生物水净化剂对养殖水体具有以下主要作用及特点：①对水质的改善起到积极作用。增加水体透明度。降解氨氮。降低化学耗氧量;②3个浓度对水质改善都有较理想的结果,其中2g／m^3组最为经济、有效;③对养殖水体的净化作用快,使用后第2天就具有明显效果;作用时间长,净化效果可维持2～3周。     

框架式模块化植物浮床构建及其生态效应

采用PVC管材作框架,并选用银纹金线蒲、金叶菖蒲和血草等3种观赏性植物构建了框架式模块化植物浮床,在上海白莲泾河道内进行水质净化试验.结果表明:这3种植物时去除河道水体中的氮、磷、COD等具有明显效果.银纹金线蒲、金叶菖蒲和血草对白莲泾水体总氮的去除率分别为58.5%、57.9%和56.1%;对总磷的去除率分别为70.1%、25.4%和28.4%;对COD的去除率分别为49.2%、47.9%和51.2%.框架式模块化植物浮床能丰富水域生物多样性,增强水体的净化作用,有效改善河道水体的水质,美化水域生态景观,且维护管理方便.     

小球藻与芽孢杆菌对对虾养殖水质调控作用的研究

通过在凡纳滨对虾养殖水体中添加小球藻和芽孢杆菌,研究其对养殖水质的调控作用。结果表明,小球藻和芽孢杆菌联合处理组对水质的调控效果优于只添加芽孢杆菌组或小球藻组。菌-藻联合处理组能很好地降低水体中氮、磷的含量,对氨氮的作用尤为明显;实验进行的第5天内,NH4 -N含量显著低于对照组(P<0·05),降低率为32·94%,NO2--N降低率为10·29%,PO34--P降低率为36·02%。小球藻 芽孢杆菌组NH4 -N含量平均为0·277mg/L,日均积累速率0·0135mg/L·d,而对照组为0·0472mg/L·d;NO2--N平均含量为0·334mg/L,日均积累速率为0·0617mg/L·d。小球藻在调控水质的同时也向水体释放有机物,从而引起水体COD的上升。     

光合细菌在盐碱地池塘改良水质的研究

研究了光合细菌（ＰＳＢ）在低洼盐碱地池塘围隔中对水化因子和浮游生物的影响。结果表明：ＰＳＢ的施用对水化因子有较大的影响,其中水体中ＤＯ、ＮＯ３－－Ｎ升高,而ＮＨ４－Ｎ、ＮＯ２－－Ｎ、和ＣＯＤ降低,而对ＰＯ４３－－Ｐ影响不明显。当ＰＳＢ浓度高时,可提高水体的ｐＨ值;对浮游生物无明显影响;ＰＳＢ的一次施用量为１０ｐｐｍ,一次效用时间为６天左右,因而ＰＳＢ可达到改良水质,进而改善水质的目的,尤其在水质恶化时,其作用更显重要。     

硫酸铜等4种药物对黄鳝鱼种的急性毒性试验

选用4种常用药物对黄鳝进行急性致毒试验。根据24 h半致死浓度TLm24的大小来判断药物对黄鳝的毒性大小。结果显示,可将其由高到低排列如下:硫酸铜>敌百虫>溴氯海因>二氧化氯。并根据TLm24和TLm48计算了各种药物的使用安全浓度。此4种药物的安全浓度分别为2.1 mg/L,2.27 mg/L,3.07 mg/L,4.6 mg/L。     

五种药物对花鱼苗的急性毒性试验

在水温20~24℃条件下,用硫酸铜、硫醚沙星、溴氯海因、二氧化氯、甲醛对花鱼骨(Hem ibarbus macu-latesB leeker)鱼苗(体长7~10 mm)进行急性毒性试验,并求出这五种药物相应的安全浓度。结果显示,这五种药物48 h的半致死浓度分别为0.23 mg/L、1.61 mg/L、3.48 mg/L、4.59 mg/、l55.96 mg/L,安全浓度分别为0.05 mg/L、0.24 mg/L、0.60 mg/L、1.04 mg/L、3.65 mg/L。表明溴氯海因和二氧化氯可安全使用,硫醚沙星和甲醛需慎用,硫酸铜不适宜在花鱼骨鱼苗的防病中使用。     

冷冻等处理对不同孵化进程的卤虫卵存活率的影响

研究了冷冻、双氧水和干燥处理对处于不同孵化进程中的卤虫卵的存活率(孵化率)的影响。冷冻对未经孵化处理的卵的孵化率影响很小,冷冻1~8周,基本保持不变。孵化进行了3h的卤虫卵,冷冻8周后,其孵化率降低了10个百分点。孵化进行了6h的卤虫卵,冷冻8周后,其孵化率降低了31个百分点。孵化进行了9h的卤虫卵,冷冻8周后,其孵化率降低了40个百分点。处于不同孵化阶段的卤虫卵经冷冻处理8周后,再经3%双氧水处理10min和40℃干燥处理6h,其孵化率表现为不同的特点。未经孵化处理卵的孵化率基本保持不变。孵化进行了3h的卤虫卵,其孵化率再次降低5个百分点。孵化进行了6h的卤虫卵,其孵化率再次降低了20个百分点。孵化进行了9h的卤虫卵,其孵化率再次降低了37个百分点。     

人工养殖栉孔扇贝和海湾扇贝血淋巴中部分免疫因子的比较研究

采用分光光度技术对人工养殖的栉孔扇贝和海湾扇贝血淋巴中部分免疫因子进行了比较研究。结果表明,海湾扇贝血清和血细胞中溶菌酶、非特异性酯酶(NSE)、过氧化氢酶(CAT)、髓性过氧化物酶(MPO)、一氧化氮(NO)、一氧化氮合酶(NOS)、活性氧和H2O2的活力或含量均高于栉孔扇贝,两种扇贝除血清中MPO活力差异不显著外,其他各组均差异极显著或显著。表明人工养殖海湾扇贝较栉孔扇贝的免疫力强。     

Effect of Water Exchange Rate on Waste Production in Semi-Intensive Shrimp Ponds During the Cold Season in New Caledonia

An experiment was conducted in six earthen ponds with 20 shrimp/m² ( Litopenaeus stylirostris ) during the cold season in New Caledonia to determine the effect of water exchange rate on characteristics of effluents and pond sediment. The nitrogen budget was established, taking into account the different forms of nitrogen in the water, sediment, feed, and shrimp. Mean water exchange rates ranged from 10 to 23% per day. Increasing water exchange rate did not cause any significant change in the average quality of the rearing environment (water and sediment) during the whole growout period. However, the results showed that increasing exchange rates boosted primary productivity. Compounds produced by the mineralisation and metabolism of organic matter (feces, uneaten feed) were exported as particulate, rather than soluble matter. The nitrogen budget showed that the amount of exported wastes from the pond into the coastal environment was only 40–50% of nitrogen inputs due to nitrogen accumulation in the pond sediments and/or release to the atmosphere. The highest accumulation of dry material, as well as the highest Δ N (concentration of total N at the end of rearing - concentration of total N before rearing), was observed in ponds with the highest WER.     

菊花心江蓠在网箱养殖区的生物修复作用

2003年8～12月，利用菊花心江蓠(Gracilaria lichenoides)在福建省东山县八尺门网箱养殖区进行生物修复实验。通过定点跟踪监测，定点连续监测，断面监测和平面监测，结果表明，江蓠对受污染的海水具有较好的修复效果。菊花心江蓠能有效提高水中的DO浓度，使修复实验区的DO浓度明显高于非养殖区和网箱养殖区的DO浓度；菊花心江蓠还能降低水中的IN、IP浓度，特别是3种价态的IN中，菊花心江蓠优先吸收铵氮，这对减轻网箱养殖区自身污染的影响更具实际意义。     

An investigation into oxytetracycline residues in Atlantic salmon, Salmo salar L.

Abstract. An outbreak of clinical furunculosis in commercially reared Atlantic salmon, Salmo salar L., broodfish in fresh water was successfully treated with a single intraperitoneal injection of oxytetracycline. The mean serum oxytetracycline residue in these fully mature fish did not decline and, at 8 weeks post-injection, was 3·7 μg/ml. In contrast, the mean serum residues in other fully mature but healthy fish declined during an 8-week experimental period to 1·3 μg/ml. The mean concentration of oxytetracycline in the liver of healthy mature fish was approximately two-fold that of similar aged but non-mature fish, and approximately four-fold the concentration found in post-smolts. Oxytetracycline residues 8 weeks after injection exceeded the minimum inhibitory concentration required for oxytetracycline sensitive Aeromonas salmonicida isolates in all groups, therefore under these circumstances, this antibiotic may be effective at a lower dose than that currently recommended. The histology of the liver from the furunculosis-surviving broodfish showed an increase in tissue lesions when compared with the other mature and non-mature fish in fresh water. The combination of prior infection and the physiological status of fasting broodfish may have influenced the rate at which this antibiotic is removed, and, in cases where these residues persist, there may be further damage to the liver.     

伊维菌素在鲫体内的药代动力学

以0.4 mg/kg的给药剂量进行口灌和肌肉注射给药,研究伊维菌素(IVM)在鲫体内的药代动力学。两种给药方式下,鲫组织中的IVM药—时曲线大都呈现多峰现象。肌肉注射给药后,药动学统计矩参数为Cmax=0.445 mg/L、Tmax=48 h、t1/2z=524.2 h、MRT(0-∞)=788 h、AUC(0-∞)=289.2(mg/L).h;口灌给药后,药动学统计矩参数为Cmax=0.264 mg/L、Tmax=8 h、t1/2z=153.9h、MRT(0-∞)=269.78 h、AUC(0-∞)=83.77(mg/L).h。两种给药方式相比,口灌组鲫对药物的吸收和清除均较快,而肌肉注射组鲫各组织中的药物浓度高,AUC值也较大。两种给药方式下,IVM在鲫各组织中AUC(0-600)值呈现相同的排列顺序,由大到小分别为性腺、血液、肾脏、肝胰脏、肌肉。IVM在鲫性腺和肾脏中均具有一定的蓄积作用,其主要表现为药物浓度高,MRT值大,且清除率低于血药的清除率,其中卵巢的积蓄作用最为明显。25℃的水温条件下,肌肉注射给药后,鲫休药期应不低于25 d;口灌给药后,鲫的休药期应不低于15 d。休药期与水温条件和给药剂量有关,因此在养殖生产过程中的休药期要根据实际情况适当调整。     

Effects of cell-cycle arrest agents on cleavage and development of loach (Misgurnus anguillicaudatus) embryos

The aim of this study was to determine the lowest concentration of nocodazole and colchicine to arrest blastomere division during the cleavage stage of loach embryos and to assess the reversibility and toxicity of the treatments in the treated embryos. Eight-cell loach embryos were incubated for 4, 8, 12, or 16 h in 1/10× Holtfreter supplemented with either nocodazole, an inhibitor of tubulin polymerization, or colchicine, an inhibitor of tubulin assembly. Complete arrest of cell cycle was observed, at a colchicine concentration of 0.996 mM and at a nocodazole concentration of 0.275 μM, respectively (the lowest effective concentration). No major morphological alteration in chromatin was observed. Reversibility and toxicity of both agents were dose and exposure period dependent. For both agents, prolonging cleavage arrest for more than 4 h (at the effective concentrations) is detrimental to development of embryos. Nocodazole treatment was less cytotoxic, whereas the concentrations of colchicine which induce cleavage arrest were detrimental to development beyond the blastula stage. Toxic effects beyond the blastula stage could be minimized for both agents by reducing the period of treatment and concentration. This revised version was published online in August 2006 with corrections to the Cover Date.     

Optimization of triploid induction by the use of 6-DMAP for the oyster Crassostrea gigas (Thunberg)

Abstract. A novel method using 6-dimethylaminopurine (6-DMAP) has recently been demonstrated to be a good triploid inductor for bivalve molluscs. The effects of 6-DMAP concentration, timing of treatment after fertilization, and treatment duration on survival and triploid induction of Crassostrea gigas (Thunberg) embryos were examined. An influence of sperm concentration was also detected and discussed. Survival to D-stage was inversely related to 6-DMAP concentration and the percentage of triploids was shown to be 6-DMAP dose dependent. Two optimal moments for treatment application were determined, corresponding to extrusions of the first and second polar bodies. Optimal treatment of 450μmol/1 6-DMAP beginning 15min after fertilization over a 10min period yielded mean survival to D-stage of 64% with a mean of 85% triploid production. As a comparison, a sample treated with 1 mg/1 of cytochalasin B (CB), 20 min after fertilization over a 15 min period, yielded a mean survival to D-stage of only 36% with a mean of 95% triploid production. The advantages of 6-DMAP over CB are clearly identified: this chemical is not carcinogenic, cheaper than cytochalasin B and much easier to use as it is water soluble.