不同抑制剂对凡纳滨对虾多酚氧化酶活性的影响

分析了凡纳滨对虾不同部位多酚氧化酶(PPO)活力的差异,并研究了抗坏血酸、曲酸、4-己基间苯二酚、葡萄糖酸-δ-内酯、植酸等抑制剂对对虾多酚氧化酶活力的抑制作用。试验结果表明,对虾头胸部的PPO活力最高。其中,0.12 g/L曲酸、2 g/L 4-己基间苯二酚5、g/L植酸对对虾PPO活力均有较好的抑制作用,对对虾处理30 min,抑制率分别为38%、36%、51%。     

凡纳滨对虾饲料中菜籽粕替代鱼粉适宜比例的研究

以饲料中添加36％鱼粉作为对照组,用菜籽粕分别替代饲料配方中10％～50％的鱼粉,配成5种等氮等能试验饲料,饲喂凡纳滨对虾,研究不同替代比例对凡纳滨对虾生长性能和虾体氨基酸组成的影响.试验结果表明,饲养56d后,随着菜籽粕替代鱼粉比例的增加,对虾的质量增加率下降,但仅50％替代比例试验组的质量增加率为1542.74％,...     

Performance of Larval and Postlarval Pacific White Shrimp,Litopenaeus vannamei (Boone), Fed Two Commercial Liquid Diet Supplements

Abstract

Two commercial liquid diet supplements were evaluated as a partial replacement for live foods fed to larval and postlarval Pacific white shrimp, Litopenaeus vannamei. Larvae were stocked in 20-L buckets at a density of 113 shrimp/L and fed one of four diets (5 replicate buckets per diet): (1) a control diet consisting of the diatom, Chaetoceros neogracile, and live Artemia; (2) the control diet plus Treflan (a fungicide); (3) LiquaLife liquid larval diet supplements with reduced concentrations of C. neogracile and Artemia; and (4) Epifeed liquid larval diet supplements with reduced concentrations of Artemia. Diets were evaluated by comparing shrimp rostro-caudal length and survival to PL-8, survival to osmotic and pH stress, as well as shrimp gut fullness, gut lipid content, and fouling. Rostro-caudal length and survival to PL-8 were not significantly different among the four treatments. However, mean survival to PL-8 was 12-34% greater in the Epifeed treatment than in the other three treatments. Shrimp fed Epifeed exhibited greater survival (P < 0.05) when exposed to 7 ppt water for two hours than shrimp in the control treatments. In contrast, there was no significant difference in survival (P > 0.05) among the four treatments when shrimp were exposed to apH of 3.35 for two hours. Although shrimp fed liquid diet supplements had more fouling (P < 0.05) than shrimp in either of the control treatments, commercial liquid diet supplements can be used in penaeid shrimp hatcheries to partially replace Artemia without compromising shrimp growth or survival.     

南美白对虾高位池养殖模式最适放养密度的调查

2003年1～6月,对海南琼山、文昌、万宁和三亚地区的51口高位虾池进行了跟踪调查。结果表明:放养密度与养殖周期、产量和饵料系数成正相关,其相关系数分别为:0.897、0.91和0.864。放养密度和饵料系数是影响养殖成本的两个主要因素,其关系可用线性回归方程:S=7.04 0.421X 1.209C来表示。高位池最适放养密度为210～255万尾/hm2。     

凡纳滨对虾商业苗种抗WSSV性能比较

白斑综合征病毒(WSSV)一直是甲壳类生物的高致病性病原。为了解市场上不同凡纳滨对虾(Litopenaeus vannamei)商业苗种病原携带情况及其抗WSSV性能,本研究收集了6个品牌的凡纳滨对虾商业苗种(分别简称为海南Z、海南S、广州P、广州Z、黄骅R和东营M),先进行包括WSSV在内的8种病原的检测,然后,采用单尾定量口饲感染方式进行抗WSSV性能测试,并比较各组苗种感染WSSV后的平均存活时间、存活率以及累积死亡率的差异。结果显示,6个商业苗种都不携带WSSV,部分苗种检测有潜在虾肝肠胞虫(EHP)和偷死野田村病毒(CMNV)。各苗种感染WSSV后,平均存活时间从长到短依次为海南Z、广州P、黄骅R、海南S、广州Z、东营M。东营M感染WSSV后第4天达到死亡高峰,而海南Z在第6~7天到达死亡高峰,比东营M晚了2~3d。感染实验结束后,海南Z和广州P存活率最高,同为72.5%,而东营M和黄骅R的存活率最低。本研究表明,海南Z和广州P抗WSSV性能最强,研究结果可为凡纳滨对虾抗病新品种的选育提供基础数据。     

Effect of Diet Size on Feeding Behavior and Growth of Pacific White Shrimp,Litopenaeus vannamei

Abstract

Six diet sizes, manufactured from crumbling large pellets, were investigated for their effect on the feeding behavior and growth of Pacific white shrimp, Litopenaeus vannamei. These diets containing 44.7% protein and 8.2% lipid were fed to 0.9 g shrimp for a period of eight weeks under indoor controlled laboratory conditions. Shrimp were stocked at a density of 12 animals per 52 L aquarium (50/m²) and were evaluated for feeding behavior, final weight, growth rate, feed conversion ratio (FCR), and survival. Feeding behavior was observed weekly starting at the beginning of the 4th week until the end of the trial. Results indicated that the variation in diet sizes did not produce significant differences in shrimp growth, FCR or survival. However, shrimp feeding behavior (in terms of total attacking incidents during feeding) was significantly different among diet sizes. This shrimp behavior was observed more frequently in aquaria fed larger diet size (3.0 mm pellet) as compared with those fed smaller diet sizes (0.7 mm and 1.2 mm crumbles). When shrimp were fed larger pellets, some of the individuals obstruct other individuals and monopolize the diet. Such “selfish” behavior of shrimp could result in considerable size variation and severe mortality of smaller individuals, which could be the case when shrimp are reared to market size. The effect of diet size on shrimp feeding behavior deserves further investigation and the use of a continuous monitoring device such as a video camera is strongly recommended. Future study should also consider various shrimp and pellet sizes more meaningful to aquaculture producers.     

凡纳滨对虾白便综合征的组织病理学观察

本文比较观察了不同规格的健康和患白便综合征凡纳滨对虾Litopenaeus vannamei肝胰腺、中肠、后肠、后盲囊等的组织结构。组织病理显示:白便综合征凡纳滨对虾肠道严重病变,肠腔空,环肌两侧增生大量成纤维细胞,这些增生细胞取代了肠上皮,而不见正常柱状上皮细胞;肝胰腺有不同程度和性质的病变,如腺管萎缩、崩解、坏死等。凡纳滨对虾患白便综合征的组织病变演变过程为:最初肠上皮基膜下出现一圈增生细胞,肠上皮柱状细胞脱离基膜;增生细胞持续增生增多,肠上皮崩解脱落至肠腔,增生细胞完全取代肠上皮;增生细胞不断增生,增生细胞层逐渐变厚,随着时间的推移,增生细胞层近腔端的一圈增生细胞坏死,出现一圈棕黄色物质,最终坏死细胞连同棕黄色物质脱落至肠腔。脱落至肠腔的腺管细胞、上皮细胞、增生细胞排出体外即为肉眼可见的白便。     

南美白对虾幼体和仔虾淀粉酶和脂肪酶活力的研究

以酶学分析方法测定了南美白对虾状幼体,糠虾和仔虾三个发育期淀粉酶和脂肪酶的活力。试验结果表明,糠虾期淀粉酶比活力显著高于状幼体和仔虾两期(P<0.05);脂肪酶比活力状幼体显著高于糠虾幼体(P<0.05)。在食性转化过程中,南美白对虾幼体消化酶活力与其食性相适应,不同发育阶段消化酶调节机制不同。     

凡纳滨对虾饲料添加剂的研究进展

凡纳滨对虾(Litopenaeus vannamei)俗称南美白对虾,是目前世界养殖产量最高的三大虾种之一,具有对水环境抗逆能力强、营养要求低、生长速度快,虾体含肉量大、肉质鲜美、营养丰富等诸多优点,自1998年来,在广东、广西、海南等省(区)广为     

Use of commercial fermentation products as a highly unsaturated fatty acid source in practical diets for the Pacific white shrimp Litopenaeus vannamei

Removal or reduction of marine ingredients (MI) from feed formulations is critical to the sustainability of the aquaculture industry. By removing MI, diets may become limiting in several nutrients including highly unsaturated fatty acids (HUFA) such as docosahexaenoic acid (DHA) and arachidonic acid (ArA). To reduce reliance on MI in shrimp diets, two trials were conducted with Litopenaeus vannamei juveniles to determine the feasibility of using fermentation meals rich in DHA and ArA as the primary source for HUFA. A practical diet with no MI was formulated with/without DHA and ArA supplements and fed in the first trial. A diet with menhaden fish oil or a combination of plant oil with/without DHA and ArA supplements was used in the second trial. To determine whether HUFA is only needed in the early growth stages, we also fed one group a HUFA‐supplemented diet to 5 g and then switched them to a HUFA‐supplement‐free diet. In both trials, the weights were reduced when HUFA supplements were not provided either throughout the trial or from 5 g to harvest (<16 g). These results suggest that supplementation of plant oils with DHA‐ and ArA‐rich oils from fermented products is a viable option to replace marine fish oil for L. vannamei.     

Use of new soybean varieties in practical diets for the Pacific white shrimp,Litopenaeus vannamei

This study was designed to evaluate the efficacy of eight sources (designated A–H) of soybean meal (SBM) which included six new non‐genetically modified soya varieties in practical feed formulation for Pacific white shrimp, Litopenaeus vannamei, using both growth and digestibility trials. A soybean meal‐based reference diet was formulated using conventional soybean meal (527 g kg^?1 diet), which was then replaced on an isonitrogenous basis with various other experimental soybean meals. In a 6‐week growth trial, shrimp in four replicate tanks per dietary treatment (10 shrimp per tank, initial weight 0.52 ± 0.04 g) were cultured in a recirculating system. There were no significant differences with respects to per cent weight gain and survival across all dietary treatments; however, final weights and feed conversion ratio (FCR) were lower in shrimp offered diet 3. Apparent digestibility coefficients for the eight (A–H) different soybean meals were determined in L. vannamei for dry matter (ADMD), gross energy (ADE) and crude protein (ADP) using 10 g kg^?1 chromic oxide as inert marker with 70 : 30 replacement techniques. Coefficients ranged from 71.3% to 88.3%, from 76.6% to 91.3% and from 93.6% to 99.8%, for ADMD, ADE and ADP, respectively. Improved digestibility values were observed in soybean C which was characterized by crude protein (471 g kg^?1), crude fat (97 g kg^?1), low cooking temperature (180 °C), higher nitrogen solubility index (689 g kg^?1) and protein dispersibility index (619 g kg^?1). This indicates that new lines of soybean meal can be used to improve digestibility coefficients in shrimp feeds.     

凡纳滨对虾虾头蛋白的内源酶水解研究

试验结果表明,凡纳滨对虾虾头蛋白白内源的最优水解条件为:40℃,pH 6,固液比1∶3,7 h,此时得氨基态氮达6.90 mg/g。从水解液检出16种氨基酸,其中含7种人体必需氨基酸。     

凡纳滨对虾感染白斑综合症病毒后的新症状

2007年6-7月,辽宁营口地区凡纳滨对虾养殖场陆续出现死虾现象,通过组织病理观察和PcR检测,确定为白斑综合症.患病初期,对虾并未表现出典型白斑、甲壳易剥离等症状,而在鳃区头胸甲内侧滋生一种囊状胶状物,导致头胸甲内侧肿胀,病理观察发现该滋生物为对虾感染白斑综合症病毒后,皮下组织"胶质化"的结果,同时胃和皮下组织的结缔组织中有大量的典型性病变核;细菌分离结果显示,伴随着弧菌和假单胞菌的混合感染.     

凡纳滨对虾不同世代生长性状的变异

对从美国进口的选育凡纳滨对虾(Litopenaeus vannamei)海南群体(进口亲虾繁育的第1世代,G1)、山东和饶平群体(G2)、湛江2和湛江3群体(G3)、湛江1和上海群体(G4)共7个养殖群体4个世代1150个个体的生长性状体长和体重进行了分析。7个群体的平均体长(范围)分别为14.76(13.25~15.99)、8.46(6.28~10.48)、9.24(4.28~10.70)、7.75(5.13~9.36)、11.38(8.13~14.12)、5.25(3.47~6.83)和7.14(4.14~9.00),变异系数分别为0.04、0.08、0.08、0.09、0.12、0.14、0.14,平均体重(范围)分别为33.41(24.33~39.74)、5.19(1.80~9.68)、6.95(3.18~11.34)、4.62(1.52~9.87)、15.03(6.00~26.96)、1.47(0.48~3.42)、3.29(0.49~6.20),变异系数分别为0.10、0.23、0.21、0.27、0.32、0.39、0.36。体长和体重的变异系数随着繁育世代的增加而增加,其中体重的变异系数每繁殖1代增加10%,其第1代的变异系数与美国选育的亲本群体相同。体长、体重相关与回归分析表明,体长与体重相关极显著(P<0.01),体长和体重的回归方程为W=0.01L2.93。表明随着繁育世代的增加,生长性状逐代分化。     

注射溶藻弧菌疫苗对南美白对虾免疫功能的影响

应用溶藻弧菌疫苗注射南美白对虾,测定了弧菌疫苗对南美白对虾免疫指标的影响以及疫苗的免疫保护作用。结果表明,注射溶藻弧菌疫苗后,血清凝集效价增强,24 h时活力达到最高值,尤其是1.08×108cell/ml组的凝集效价升高最明显,为对照组的6.0倍;在24 h时,3个试验组的凝集效价均明显高于对照组(P<0.05)。溶菌活力注射后6 h即达到最高值,1.08×107、1.08×108cell/ml组的溶菌活力明显高于对照组(P<0.05)。抗菌活力在注射后3 h时最高,明显高于对照组。溶血活力在注射疫苗后有所增强,注射后6 h时1.08×106、1.08×107cell/ml组的活力达到最高,而1.08×108cell/ml组12 h时活力达到峰值。注射疫苗对血清超氧化物歧化酶活力基本没有影响。1.08×106、1.08×107、1.08×108cell/ml对南美白对虾的免疫保护率分别为46.3%、61.0%和75.6%。     

拟诺卡氏菌骨架对凡纳滨对虾生长及免疫功能的影响

将研究室分离纯化的卢森坦拟诺卡氏菌扩大培养,发酵液经过超声波破碎、离心、胰蛋白酶酶解、脱脂、冷冻干燥,得到白色细胞壁骨架。在基础饲料中添加0.1%和0.2%的拟诺卡氏菌细胞壁骨架,饲喂凡纳滨对虾幼虾[体质量(4.21±1.28) g],养殖周期为4周,测定各处理组对虾体质量,统计各组存活率,使用南京建成试剂盒测定对虾血淋巴和肝胰腺组织中的一氧化氮合酶、超氧化物歧化酶、酚氧化酶、溶菌酶、谷胱甘肽过氧化物酶活性及丙二醛的含量,佛波豆蔻酸乙酯法检测对虾血淋巴中呼吸爆发活性,采用副溶血弧菌对剩余对虾进行攻毒,统计对虾死亡率。试验结果显示,拟诺卡氏菌细胞壁骨架能够明显促进凡纳滨对虾的生长,显著提高对虾血淋巴和肝胰腺中的超氧化物歧化酶、一氧化氮合酶、酚氧化酶、溶菌酶、谷胱甘肽过氧化物酶的活性( P <0.05, P <0.01),显著降低丙二醛浓度( P < 0.01 ),显著增强对虾血淋巴的呼吸爆发活性( P <0.05, P <0.01),可提高对虾的免疫保护率,从而提高凡纳滨对虾的存活率。研究结果表明,拟诺卡氏菌细胞壁骨架的适宜添加量为0.1%。     

凡纳滨对虾α-淀粉酶基因的SNPs检测

利用PCR产物直接测序法,对凡纳滨对虾SPR和SPF 2个品种共40个样本的α-淀粉酶基因(GenBank序列号:AJ133526)的单核苷酸多态性(SNP)进行了研究。找到9个SNPs,分别为:C127T、A138G、T951C、T1083C、C1457T、A2147C、A2226G、A2297G和T2306C。其中1个SNP是第4外显子中的错义突变,2个SNPs分别是第5和第7外显子中的同义突变,6个SNPs是内含子中的突变。这些结果可为凡纳滨对虾的研究提供遗传学依据。     

4株凡纳滨对虾肠道益生菌分离、鉴定及应用研究

为将凡纳滨对虾肠道分离的益生菌用于对虾的养殖,利用乳酸菌培养基分离对虾肠道中的益生菌并对菌株进行初步分类鉴定,利用体外抑菌方法筛选有抗菌活性的菌株,用于考察对虾实验室养殖过程中抗有关致病菌的效果。试验结果显示,自虾肠道分离得到W7、W25、W27、W31菌株,分别属于啤酒酵母、短小芽孢杆菌、枯草芽孢杆菌沙漠亚种和暹罗芽孢杆菌,它们对致病菌副溶血弧菌、金黄色葡萄球菌和沙门氏菌有一定的抗菌活性,其中暹罗芽孢杆菌W31抗菌效果最好。将啤酒酵母W7和暹罗芽孢杆菌W31菌体与饲料混合用于对虾的养殖,能够明显增强凡纳滨对虾抵抗弧菌侵染的能力,提高存活率。     

跑道式南美白对虾养殖池中弧菌的数量动态

采用TCBS平板计数法对南美白对虾跑道式养殖池和土塘养殖塘水样弧菌数量进行了一个养殖周期的连续监测。结果表明:跑道式养殖池水体中弧菌数在放苗后的前70 d均较低,随后迅速增加并维持在一个较高水平,变化幅度为15.0~1.42×104cfu/ml,平均3.96×103cfu/ml,平均数比土塘高2倍。跑道式养殖对虾始终未发病,跑道式养虾病害少,产量高。