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苏北浅滩中部海域春秋季口足目和十足目虾类分布特征 总被引:1,自引:0,他引:1
根据2010年5月和9月苏北浅滩如东海域虾类调查资料,研究了苏北浅滩中部海域口足目和十足目虾类种类组成和多样性的时空分布,探讨了主要优势种密度对总优势种密度的影响,并结合该海区地形地貌、水文环境等因素对虾类多样性进行了分析。结果表明,在2次调查中,共鉴定出十足目18种,口足目2种。依据相对重要性指数IRI的计算,得出该海域春季主要优势种为葛氏长臂虾(Palaemon gravieri),秋季为哈氏仿对虾(Parapenaeopsis hardwickii)。尽管春季各站位平均种类数稍高于秋季,但秋季虾类种间分布较均匀,致使该海域虾类重量和尾数多样性指数(H')均值秋季(1.59,1.85)皆高于春季(1.13,1.57)。不同生态类群虾类种类变化形成季节更替,更替率为55%。黄海冷水团和长江冲淡水的季节变化是影响该海域虾类种类生态类群和多样性分布的主要水文因素。 相似文献
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A feeding trial was conducted to determine the dietary folic acid requirement of juvenile grass shrimp, Penaeus monodon. Purified basal diets were formulated using vitamin-free casein as the protein source. Graded levels (0, 1, 2, 5, 10, 15, 30, and 60 mg folic acid/kg diet) of folic acid were added to the basal diet, resulting in eight dietary treatments in the experiment. Each diet was fed to three replicate groups of shrimp initially averaging 0.79±0.01 g for 8 weeks. Shrimp fed diets supplemented with 2 mg folic acid/kg diet had greater (P<0.05) weight gain and hepatopancreatic folic acid concentrations than shrimp fed the unsupplemented control diet. Feed efficiency (FE) was highest in shrimp fed the diets supplemented with 2 mg folic acid/kg diet, followed by the groups fed 1 mg/kg, then the control group. Hepatosomatic index (HSI) was highest in shrimp fed the control diet, followed by 1 mg folic acid/kg and lowest in shrimp fed diets supplemented with 2 mg folic acid/kg. Weight gain percentage, hepatopancreatic folic acid concentration and hepatosomatic index of the shrimp analyzed by broken-line regression indicated that the adequate dietary folic acid concentration in growing P. monodon is 1.9–2.1 mg/kg diet. 相似文献
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2003年4~5月利用低盐度(12)河口水在上海崇明进行了轮虫土池培育实验,并对其脂肪酸营养进行了分析和评价。经过33d培养,结果表明,(1)只要管理得当,低盐度、自然水温(平均水温为18.2℃)条件,土池培育轮虫可以实现持续稳定供应,采收时间、每日采收量和亩总产量分别达到28~29d、9.2kg/667m2·d和259kg/667m2,最高密度可达45个/ml;(2)敌害生物和饵料条件是土池培育轮虫持续稳产的关键因素;(3)土池培育轮虫EPA、DHA、AA等HUFA含量高于酵母和微绿球藻培育的轮虫,因此土池培育轮虫的营养价值好,适用于海水苗种培育。 相似文献
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Herwig Waidbacher David M Liti Maria Fungomeli Raphael K Mbaluka Jonathan M Munguti & Michael Straif 《Aquaculture Research》2006,37(6):594-600
The effects of pond fertilization and feeding rate on growth, economic returns and water quality were investigated to develop a low‐cost cage‐cum‐pond integrated system for production of Oreochromis niloticus (L.). Hand‐sexed male fingerlings averaging 19±0.39 and 32±0.69 g were stocked in cages and open ponds at 150 fish cage?1 and 2 fish m?2 respectively. Fish were cultured for 114 days in five triplicate treatments. Cages were installed into ponds and caged fish were fed a 24% protein diet at 3% (T1) and 6% (T2) body weight day?1 (BWD) without pond fertilization, and 6% BWD with pond fertilization (T3). The open water in the fourth treatment (T4) was not stocked but contained caged fish, which were fed 6% BWD for the first 57 days followed by 3% BWD for the remaining period. Ponds in the control (T5) had no cages and were neither fertilized nor open‐pond fish fed. Feeding rate and pond fertilization significantly (P<0.05) affected fish growth, profitability and water quality among treatments. Fish growth, feed utilization, fish yield, water quality and profits were significantly (P<0.05) better in T3 than the other treatments. It was concluded that fish production and economic returns were optimized at 6% BWD in fertilized ponds. 相似文献
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白斑综合征病毒环介导等温扩增快速检测方法的建立 总被引:1,自引:0,他引:1
根据对虾白斑综合征病毒(WSSV)囊膜蛋白VP28基因保守序列,利用Primer Explorerv 4.0软件设计了4条引物,建立了白斑综合征病毒环介导等温扩增快速检测方法,对反应温度和反应时间等参数进行了优化,同时将建立的LAMP检测方法与巢式PCR进行了比较分析。结果表明,LAMP最适反应在64℃恒温条件60min内完成,凝胶电泳呈现梯型条带;反应体系中添加SYBR Green I荧光染料后,绿色的阳性结果明显区别于橙色阴性结果。LAMP方法的最低检出限为100拷贝/μL,灵敏度较巢式PCR高100倍,而且LAMP方法在1h内即可完成检测,操作简单,无需复杂仪器,肉眼可直接观察检测结果。用建立的LAMP方法对临床发病南美白对虾样品进行了检测,结果表明,LAMP方法适合对虾白斑综合征病毒的现场快速检测。 相似文献
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有益微生物对海水养虾池浮游生物生态特征的影响研究 总被引:9,自引:6,他引:9
研究了有益微生物对海水虾池浮游生物生态特征的影响。通过对虾养殖系统中浮游动物与浮游植物进行为期3个月的监测,结果表明试验组虾池的浮游植物密度表现为前期低,中期迅速增长,后期达顶峰,并维持在70×106~160×106cell·L-1的水平,前期种类以硅藻类为主,后期则以绿藻类为主;同时试验池浮游动物的密度也保持稳定增长态势,并在养殖后期维持在顶峰水平,密度达到25×103~30×103ind·m-3,种类以广盐、适低盐的沿岸种为主,但优势种明显;对照池的浮游植物和浮游动物呈现前期低后期高的态势。其变化差异表现为对照组的浮游植物和浮游动物在后期的密度变动起伏较大,且出现较大比例的有害的兰藻类,而试验池的兰藻类只占较少的比例,说明芽孢杆菌群能抑制兰藻类的繁殖,促进有益藻类生长;浮游生物的多样性指数较低,低于自然海区,但种类均匀度则较高,与自然海区相当。 相似文献
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Evaluation of shrimp polyculture system in Thailand based on stable carbon and nitrogen isotope ratios 总被引:1,自引:0,他引:1
HISASHI YOKOYAMA JUNYA HIGANO a KUMIKO ADACHI YUKA ISHIHI YOSHIHIRO YAMADA b 《Fisheries Science》2002,68(4):745-750
ABSTRACT: To quantify the contribution by cocultured animals to waste assimilation in an intensive shrimp farm in Thailand, the food web structures of the macrobenthos in a reservoir pond, a shrimp culture pond and water treatment ponds were examined using the stable C and N isotope ratio technique. Seawater for aquaculture was drawn from a creek, and stored in a reservoir pond, used for farming the banana prawn Fenneropenaeus merguiensis in culture ponds, and then recycled through treatment ponds where the green mussel Perna viridis was cultured to remove organic wastes discharged from the farming. The clam worm Nereididae sp. and the mud creeper Cerithideopsilla cingulata in the culture pond had δ 13 C values of −21.0‰ and −18.4‰, respectively, suggesting that shrimp feed (mean δ 13 C = −20.7‰) was the main food source for these species. The δ 13 C analysis also suggested that sediments (−23.7‰) in the reservoir pond and particulate organic matter (POM) (−24.0‰) and/or sediments (−25.0‰) in the treatment pond supplied carbon for most macrobenthic animals. However, green mussels in the treatment pond had a mean δ 13 C value of −20.5‰, suggesting that shrimp feed was the main food source for this species. 相似文献