三疣梭子蟹与不同虾类混养技术研究

分别利用中国明对虾、凡纳滨对虾、日本囊对虾和脊尾白虾等虾类与三疣梭子蟹进行混养。结果表明:日本囊对虾与三疣梭子蟹混养组三疣梭子蟹养殖单产最高,平均产量1678.5 kg/hm2,其次为凡纳滨对虾与三疣梭子蟹混养组,平均产量1659 kg/hm2。对虾养殖单产以凡纳滨对虾与三疣梭子蟹混养组最高,平均产量990 kg/hm2,其次为中国明对虾与三疣梭子蟹混养组,平均产量952.5 kg/hm2。但考虑到日本囊对虾市场售价为其他混养虾类的两倍,因而日本囊对虾与三疣梭子蟹混养组养殖效益最高。     

三疣梭子蟹单体筐立体养殖技术研究

鉴于传统三疣梭子蟹的土塘养殖由于养殖环境受诸多情况影响,导致养殖成活率低。研究采用单个体筐养设施进行三疣梭子蟹高产立体养殖技术。结果表明:使用新技术后,单体筐养成活率达到71.95%和立体养殖平均产量达到4 500kg/hm2,单位面积产量大幅度提高。     

海水池塘刺参—日本对虾—三疣梭子蟹—菊花心江蓠生态混养技术

为提高刺参养殖池塘水体空间的利用率,增加产量和效益,构建了一种刺参—日本对虾—三疣梭子蟹—菊花心江蓠生态混养模式,试验结果显示,该模式的单产高达3 191.25 kg/hm2,其中刺参(Apostichopus japonicus)单产 1 875 kg/hm2,日本对虾(Penaeus japonicus)504 k...     

三疣梭子蟹人工高密度育苗试验取得初步成功

河北省水产研究所于1986年,采用河蟹人工高密度小水体的育苗技术及工艺,对三疣梭子蟹的人工育苗作了试验,取得了良好的效果:在4只一吨水体的玻璃钢水槽中,经14天的人工培育,共育出三疣梭子蟹苗416,800只,折合重量为2,605g,平均为104,160只,最高单产为307,200只,最高成活率为66%,平均成活率为36.5%。同时对三疣梭子蟹幼体的摄食习性及喂养技术、病     

梭子蟹苗的选购与暂养

1993年对虾发病以来,我区逐步探索出虾、蟹、贝混养的虾池综合利用新路子,梭子蟹已成为虾池养殖的主导种,取代了对虾的养殖地位.1999年,我区养殖梭子蟹800 hm2,实现总产量630 t,利润1 347万元,平均单产787.5 kg/hm2,平均利润16 837.5元/hm2.分析我区1999年养殖情况,90%的养殖户盈利(养成成活率高于12%可盈利),梭子蟹平均养成成活率26%左右,高的达50%,低的不足5%,差异很大.     

梭子蟹土池原池育苗与养殖技术

近年来,随着梭子蟹土池育苗技术的广泛推广,象山县高塘岛乡133 hm2海水池塘推广了梭子蟹土池原池育苗与养殖技术.由于梭子蟹苗种于原池已经适应了池塘环境,因此原池养殖十分顺利,近三年连续获得成功,梭子蟹平均单产达到900～1 125 kg/hm2,再加上混养的脊尾白虾和缢蛏,平均产值达到12万元/hm2左右、利润达到6万元/hm2以上.     

梭子蟹池塘养殖技术的研究

利用不同面积、水深、底质的池塘,设置不同的隐蔽物,采用不同的放养密度,放养不同规格的苗种,调节不同的透明度进行试验。结果表明:梭子蟹养殖池塘以面积在5亩~30亩、水深在1.5m~2.0m、底质为泥沙质和沙泥质,养殖效果较好;幼蟹规格为720只/kg时,亩放养2000只~2500只,单产较高;随着放养密度增大,成活率逐渐降低;放养苗种规格越大,养殖成活率越高,试验条件下,放养规格为1000只/kg的苗种,单产最高;透明度为30 cm~40 cm的池塘,平均单产、成活率均较高,设置隐蔽物对防止梭子蟹互相残杀效果不明显;透明度大于40 cm时,设置隐蔽物的池塘养殖梭子蟹的成活率明显高于对照池塘、     

三疣梭子蟹池塘饲养试验

在面积为1.53hm^2的海水池塘中放养三疣梭子蟹蟹苗(Ⅱ期仔蟹)9万只，经95d的饲养，共收获商品蟹1658kg，平均体重128g，单产1101．3kg／hm^2，盈利34456元。     

池塘集约化养殖日本锦鲤试验

集约化池塘养殖6个月,主养塘共产日本锦鲤2 260 kg,鲢鳙鱼种980 kg,折合单产23 143 kg/hm2,成活率为98%,锦鲤平均规格144 g/尾;混养塘中锦鲤成活率达100%,2号塘锦鲤平均规格为133 g/尾,3号塘锦鲤平均规格为200 g/尾。     

唐山大清河盐场注水池三疣梭子蟹与日本对虾生态混养试验

为持续提高盐田养殖效益,在唐山大清河盐场注水池连续三年进行了三疣梭子蟹(Portunus trituberculatus)与日本对虾(Penaeus japonicus)生态混养,试验结果显示,该模式三疣梭子蟹雄蟹平均产量达到637.5 kg/hm²,雌蟹平均产量达到787.5 kg/hm²,日本对虾平均产量达到236.25 kg/hm²。     

水硬度对七彩神仙鱼幼鱼发育的影响

采用不同硬度的水对七彩神仙鱼幼鱼进行饲养。6周龄幼鱼在硬度为7.94°dH±0.30°dH时饲养84d后,比在硬度为14.71°dH±0.23°dH水中的幼鱼个体大,生长速度快。表明较高硬度的水有利于七彩神仙鱼幼鱼的生长发育。     

Estimation of variation of virulence of Renibacterium salmoninarum by survival analysis of experimental infection of salmonid fish

The variation of virulence of Renibacterium salmoninarum , the causative agent of bacterial kidney disease (BKD) in salmonid fish, was studied by infecting rainbow trout, Oncorhynchus mykiss (Walbaum), with two isolates (strains 325 and 932) from diseased Atlantic salmon, Salmo salar L., and one isolate (strain 4366) from an apparently healthy Atlantic salmon. Coho salmon, Oncorhynchus kisutch (Walbaum), were injected with the strain 932 to estimate difference in fish species resistance. Fish were removed by random sampling for other study purposes, a study design possible with analysis of lifetime distributions incorporating both sampling-, death- and survival-times. At the end of the experiment, the rainbow trout infected with strains 325, 932 and 4366 had a survival probability of 33%, 51% and 72%, respectively. The coho salmon infected with strain 932 had a 26% survival probability. The strain differences were significant according to the log-rank test, and the risk ratio between the strains ranged from 1·8 to 5·4. The strain from the apparently healthy fish was least virulent. The survival of the fish species was different over time. Rainbow trout were more likely to die early in the time course, but high numbers of coho died later, resulting in an overall risk of mortality of 1·4 in favour of rainbow trout. Differences in virulence may reflect changed selective pressure on R. salmoninarum when introduced from feral stocks into the environment of fish farms.     

Characterization of protease inhibitors of seminal plasma of cyprinids

Anti-proteinase activity was demonstrated in the seminal plasma of cyprinid fish species (bream, chub, ide, dace, asp, goldfish, roach, common carp) using electrophoretic techniques combined with a detection method based on inhibition of bovine trypsin. We found species-specific protease inhibitors in the seminal plasma of cyprinids. At least three bands of protease inhibitors with different migration rates could be identified by native PAGE. Higher variability was characterized for bands with slower migration rates. Visualization of inhibitors after SDS-PAGE under non-reducing conditions allowed estimation of their molecular weights. Apparent molecular weights were within the range of 51–59 and 47–54 kDa for the bands with slower and moderate migration rates, respectively. The molecular weight of fast migration bands for roach and common carp were estimated to 23 and 30 kDa, respectively. Inhibitors of common carp seminal plasma differed in their affinity toward serine proteases. Three inhibitors in common carp seminal plasma could be visualized using cod and bovine trypsin, but only two inhibitors (of high molecular weight) were recognized with chymotrypsin. There were differences in anti-proteinase activity and seminal plasma protein concentration in relation to the origin of common carp seminal plasma (breeding lines) and time of milt collection (spawning vs. post-spawning season).     

浅谈船舶干舷的作用

近几年．在唐山沿海发生的渔船海难、海损事故经统计表明呈增多趋势。这与出海作业渔民的安全意识不强有很大关系．渔民为了挣取更多的效益,在海上,超抗风浪等级作业且人为地增加船的不规范载荷．造成船的储备浮力损失,酿成恶果。笔者认为．在渔船设计建造中,留取的干舷对渔船作业的安全性起相当重要的作用,必不可少。 一、储备浮力的重要性 所谓储备浮力就是自船舶设计水线至水密甲板的水密部分体积,其大小与干舷相关．于舷大则储备浮力大,干舷的重要性就在于能够使船在海中保持正常的浮性和安全。再者,在设计建造渔船时,为了改善…     

斑节对虾虾苗活力检测方法

该研究通过肉眼观察、镜检,进行干露、饥饿、盐度突降、福尔马林等抗性试验,并采用病毒检测等方法,以期建立评估斑节对虾（Penaeus monodon）虾苗活力和质量标准。结果表明,斑节对虾健康虾苗具有趋光性、集群性,体表光洁,肌肉透亮,肠胃食物充盈等特性。测试虾苗干露时间以15min为宜,健康虾苗干露后能立即恢复活力,而病弱虾苗多出现死亡、昏迷现象;虾苗的成活率随饥饿时间的延长而降低,随福尔马林浓度升高和时间延长而降低,随盐度突降幅度增加而降低。健康虾苗能忍受100～200μL·L^-1福尔马林溶液30min,成活率近100％;在盐度20～30下虾苗的成活情况较好,而其在淡水中仅能存活1h。对虾苗进行病毒检测,可以避免养殖中因虾苗携带病毒而可能导致的病毒性疾病的暴发。     

金鳟、虹鳟苗种长途运输实例

鳟鱼发眼卵和旨种运输是养鳟生产的重要环节。发眼卵多在冬季和早春运输,苗种多在晚春和夏季运输。苗种运输大多以鱼篓充氧进行短距离汽车运输,长途运输冷水性鱼苗种的实例很少。本文总结了金鳟和虹鳟苗种长途运输方法,以期与养鳟业界共同交流提高。一、包装材料和方法内包装材料是苗种运输专用塑料袋,规格54×104cm,外包装是泡沫塑料箱,规格63.5×45.5×30．5cm,纸箱规格64×46×32．5cm。塑料袋采取双层式,内装苗种和水共12.5kg,其中苗种0.5-1．3kg,100－2000尾。起运前苗种停食1－2天。运鱼用水水温调至6℃,鱼、水入袋后袋内…     

同工酶(Isozyme)分析技术及其在紫菜(Porphyra)研究中的应用

同工酶是基因表达的直接产物,反映了编码蛋白质的DNA序列信息。利用同工酶分析技术不仅能区分紫菜叶状体的不同同工酶特征,而且能表现微型孢子体（丝状体）同工酶特征,利用不同种类和不同品系的紫菜丝状体的同工酶谱进行遗传多样性分析,对紫菜种质鉴定、遗传图谱的构建、寻找紫菜遗传多样性中心地区、筛选优良品种、进行种质改良研究都具有特别重要的意义。     

合浦珠母贝选育家系的遗传多样性分析

该研究选取具有多态性的6对微卫星引物对构建的2批合浦珠母贝(Pinctada fucata)完全双列杂交家系的遗传多样性进行了分析。6个微卫星标记在9个家系360个个体中共检测到32个等位基因,有效等位基因(Ne)为1.758 7~3.586 5,观测杂合度(Ho)为0.144 4~0.488 9,期望杂合度(He)为0.432 0~0.722 2,Shannon指数(I)为0.691 9~1.507 4。9个家系都有单态位点,平均Ho为0.129 2~0.466 7,平均He为0.155 0~0.439 6,平均I为0.248 5~0.712 2。有19个位点(占35.19%)极显著地偏离Hardy-Weinberg平衡。各家系之间的遗传距离为0.109 0~1.137 2,遗传相似性系数为0.320 7~0.896 8。家系L4B46与L4B48的遗传距离最大,与D3D313的遗传距离最小。UPGMA法聚类分析显示,9个家系分为3支,L4B48单独成一支,B4D426、B4D427与D4B445聚成一支,其余家系聚成一支。该研究结果为合浦珠母贝家系选择育种的亲本选择与交配设计提供了科学依据。     

母猪胎衣不下的病因与防治要点

猪的胎盘属于弥散型胎盘,这种胎盘的结构特点和饲养管理的不当,常常导致母猪胎衣不下发生,给生猪的生产繁殖带来极大损失。本文针对母猪胎衣不下发生病因、综合防治进行详细阐述,旨在对预防和治疗胎衣不下能有所帮助。     

A History of the Development of Sensory Methods for the Evaluation of Freshness of Fish

It is well-established in fish technology that freshness should be measured primarily by sensory procedures, though considerable effort has been expended in looking for nonsensory alternatives. A variety of methods for sensory evaluation of freshness has been described and this historical review traces developments of these methods. Much of the source material derives from the research literature such as research journals and reports of research, and the use of sensory methods in commercial quality control has scarcely been documented. There is a brief discussion of possible future developments in sensory evaluation of freshness.