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31.
对虾皮下及造血组织坏死杆状病毒的精细结构、核酸、多肽及血清学研究 总被引:26,自引:3,他引:26
对纯化的对虾皮下及造血组织坏死杆状病毒(HHNBV)进行了超微结构、紫外吸收、核酸类型及多肽SDS-PAGE的研究。同时用单克隆抗体对HHNBV的两分离株和MBV进行了血清学比较研究。用TMV作为内标定物测得病毒粒子大小为150nm×450nm,其衣壳为两个帽状物端夹13圈螺旋对称的园柱体结构。病毒在260nm处吸光系数为0.117mg/mL/OD260。病毒核酸为双链DNA,分子量大于35×106d。病毒囊膜有12种主要多肽。病毒衣壳有两种主要多肽。从寿光(HHNBV—937)和青岛(HHNBV—938)分离到的病毒种在SDS—PAGE和抗HHNBV—937单抗ELISA反应上没有显著差异。HHNBV与斑节对虾杆状病毒(MBV)在抗原决定簇上存在差别。 相似文献
32.
Rajabdeen Jannathulla Vanjiappan Rajaram Rajamohamed Kalanjiam Kondusamy Ambasankar Moturi Muralidhar Jagabattulla Syama Dayal 《Aquaculture Research》2019,50(12):3493-3506
Fishmeal is being trusted as the most reliable protein source due to its nutritional quality in terms of attractability, palatability, digestibility, excellent nutrient profiles to fulfil the dietary requirement of aquatic species. The aquaculture sector consumes >70% of global fishmeal, though aqua feeds constitute only 4% in total industrial feed production (900–1,000 Mt in 2018). The global fishmeal production has shown a downward trend of 26.50% during 2000 to 2018 due to the occurrences of El Niño–Southern Oscillationsand other climatic events, which in turn increased the fishmeal price from 452 USD/t (2000) to 1596.54 USD/t (2018). The increasing trend of aquaculture production along with reduced fish‐in/fish‐out ratios (0.63 in 2000 to 0.33, 0.22 in 2010 and 2015 respectively) indicates the resilience of the aquafeed sector for fishmeal replacement. The wide availability, reasonable price and reliable nutrient content made an interest in plant protein sources, but their utilization was limited due to poor digestibility, imbalanced profiles of essential nutrients and the presence of anti‐nutrients. Numerous methodologies are invented in recent times to enrich the nutritional qualities for maximizing the utilization of plant proteins in aquafeed formulations. The present review concludes that the aquafeed sector should use climate economics and technological innovations for substituting fishmeal to formulate the cost‐effective feeds. 相似文献
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环境胁迫对对虾免疫系统的影响研究 总被引:2,自引:0,他引:2
环境胁迫(environmental stress)是指环境对生物所处的生存状态产生的压力,分为急性环境胁迫和慢性环境胁迫。捕捞、干扰、水质的突变等可以引起急性环境胁迫,而水质逐渐恶化和高密度放养等会造成慢性胁迫。近年来随着人类活动范围的不断扩大和程度的加深,环境资源受到了很大的破坏,养殖对虾受到的环境胁迫日益严重。这些胁迫可使对虾产生应激反应,虽然这是一种保护性反应,但持续处于应激状态,机体的免疫防御体系的功能会受到抑制,就会影响到其抗病力。当前对虾的病害越来越严重,大规模的死亡已经成为制约养殖业发展的瓶颈。 相似文献
35.
1999年在胶州市李格庄镇低洼盐碱地原淡水养鱼池塘改建中国对虾养殖池塘,在池塘边上打井提供养殖用水,井水盐度一般在10-12左右;虾苗在水泥池淡化7天使盐度降为15,经暂养后陆续分至养殖池,暂养成活率76.11%;养成阶段主要使用配合饵料,添加抗病药物;前期以添加水为主,养殖中后期少量换水,平均日换水量不超过5%,并定期使用水质净化剂。结果5个养殖池对虾平均亩产90.83kg。 相似文献
36.
Rémi Mongruel Olivier Thébaud 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):163-181
ABSTRACT Most marine aquaculture activities remain strongly dependent on coastal ecosystems. In the case of shellfish farming, this dependency is related mainly to water quality and to the various ecological interactions resulting from the dynamics of coastal food webs. Such ecological constraints have influenced the overall evolution of blue mussel farming in the Mont-Saint-Michel Bay, leading producers to negotiate collective arrangements regarding production capacity and techniques and to develop production strategies at the farm level. This article presents an analysis of the location choices of mussel farmers in the Mont-Saint-Michel Bay based on an empirical investigation conducted in 2002. A typology of farms with respect to their land structure is developed in which some farms choose to concentrate their activity in a single part of the bay while others distribute their activity more widely. Determinants of the location choices of each farm category, including distance to port, natural productivity differentials, and predation of mussel stocks, are analyzed. The role of the institutional arrangements allowing mussel farmers to develop these location strategies is also discussed. 相似文献
37.
ABSTRACT: A feeding trial was conducted to estimate the minimal dietary potassium (K) requirement for juvenile grass shrimp Penaeus monodon . Purified diets with seven levels (0, 0.3, 0.6, 0.9, 1.2, 1.5, 2.0 g/100 g) of supplemental potassium were fed to P. monodon (mean initial weight 0.75 ± 0.01 g) for 8 weeks. Each diet was fed to three replicate groups of shrimp. The rearing water contained 360 mg/L potassium. Weight gain and protein efficiency ratio (PER) of shrimp improved as dietary potassium supplementation level increased up to 1.5 g K/100 g diet and thereafter declined significantly ( P < 0.05). Feed efficiency (FE) of shrimp also showed a similar trend. However, whole body K concentration of the shrimp kept an increasing trend up to 2.0 g K/100 g diet. Analysis of the weight gain (percent) and PER of the shrimp by polynomial regression indicate that the minimal dietary potassium requirement in growing P. monodon is approximately 1.2 g/100 g. 相似文献
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39.
A peptide with high antioxidant activity was isolated and identified from shrimp processing by-products hydrolysate. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was used to evaluate the antioxidant activity of fractions. The purified antioxidant peptide was identified as Ser-Val-Ala-Met-Leu-Phe-His (804.4 Da) by electrospray ionization tandem mass spectrometry. The purified peptide at 50 μg/mL showed antioxidative activity of 65.7 ± 0.9%, which was 3.18-fold higher compared with the first step separation by ion-exchange chromatography. It is possible to produce natural antioxidative peptides from shrimp processing by-products hydrolysate. The high antioxidant activity may be due to the presence of Phe-His segment at the C-terminus of the peptide. 相似文献
40.
Francisco J Magallón Barajas Rosalía Servín Villegas Guillermo Portillo Clark & Berenice López Moreno 《Aquaculture Research》2006,37(5):492-499
Transport of post‐larvae shrimp used in aquaculture is an important element of successful cultivation because of the potential for stress during stocking procedures. To find optimum transport conditions, several bioassays were performed in the laboratory to evaluate survival of whiteleg shrimp Litopenaeus vannamei 5–30‐day‐old postlarvae under conditions similar to those encountered during transport from the hatchery to nursery and shrimp ponds. Postlarvae were exposed for 4 h to different temperatures and pH levels ammonia concentrations. Survival was significantly reduced after a 4 h exposure to pH 9 and was inversely related to temperature with or without 7 mg L?1 of ammonia. The 15‐ and 20‐day‐old postlarvae had higher survival rates than other ages. The lowest survival occurred in alkali conditions (pH 9), with 7 mg L?1ammonia at 30 and 32°C. To assure optimal survival of postlarvae during transfer from the hatchery to the nursery and shrimp ponds, we recommend temperatures below 28°C, pH no higher than 8, no ammonia and post‐larval age at least 15 days. 相似文献