凡纳滨对虾和斑节对虾对WSSV敏感性的比较

用6.0×104拷贝、1.2×104拷贝和6.0×103拷贝3种剂量白斑综合症病毒(WSSV)对凡纳滨对虾和斑节对虾进行人工注射感染,比较了两种对虾对WSSV敏感性的差异。结果表明,凡纳滨对虾死亡时间随病毒剂量降低而延长,斑节对虾死亡时间没有明显差异;随病毒剂量的降低,凡纳滨对虾人工注射感染后病毒复制高峰时间显著延长,斑节对虾感染后病毒复制高峰时间相同,WSSV在凡纳滨对虾体内比在斑节对虾体内复制慢。对虾携带WSSV数量最低为3.3×107拷贝.g-1,最高为4.3×108拷贝.g-1。凡纳滨对虾比斑节对虾对WSSV的抵抗性更强。     

凡纳滨对虾与点带石斑鱼的混养模式

对凡纳滨对虾(Litopenaeus vannamei)与点带石斑鱼(Epinephelus malabaricus)进行90 d的混养试验,研究点带石斑鱼混养密度、规格对凡纳滨对虾生长、成活率和产量的影响。结果表明,点带石斑鱼混养密度、规格均对凡纳滨对虾生长、成活率和平均产量的影响有统计学意义(P0.05)。在混养密度相同的条件下,混养小规格点带石斑鱼的凡纳滨对虾成活率比混养大规格点带石斑鱼提高15.1%~23.2%,平均产量比混养大规格点带石斑鱼提高19.0%~40.6%。随着点带石斑鱼混养密度增加,凡纳滨对虾成活率和平均产量呈下降趋势。小规格点带石斑鱼混养密度分别为0.4尾·m-2时,凡纳滨对虾成活率和平均产量最高,分别为66.25%%±7.24%、(1 181.0±101.8)kg,较单一养殖凡纳滨对虾成活率提高5.46%,平均产量提高16.2%;大规格点带石斑鱼混养密度为0.2尾·m-2时,凡纳滨对虾成活率和平均产量最高,分别为(52.04±6.11)%、(959.8±89.1)kg,但较单一养殖凡纳滨对虾成活率下降8.75%,平均产量下降5.88%     

急冷与空气暴露联合胁迫对凡纳滨对虾生理代谢影响

【目的】探明无水保活流通过程中凡纳滨对虾(Litopenaeus vannamei)响应急冷(acute cold,AC)与空气暴露(waterless duration,WD)联合胁迫的生理代谢调节规律。【方法】研究模拟产业运输实际,分析联合胁迫(AC+WD)进程中凡纳滨对虾血液和肝胰腺典型生化指标,以及肝胰腺组织病理变化。【结果】AC胁迫后,凡纳滨对虾生理应激指标血清皮质醇含量由正常组(normal control,NC)的(326.90±4.61)pg/mL显著增加到AC组的(427.16±7.92)pg/mL(P<0.05),AC+WD组则随时间延长而逐渐降低。血清葡萄糖含量在联合胁迫6 h后达到最大值(26.31±1.05)mg/dL,乳酸在9 h达到峰值(7.90±0.11)mmol/L。AC及AC+WD组中血蓝蛋白、尿素氮和肌酐含量较NC组均发生不同程度的增加,而总蛋白含量先升后降,总胆固醇和甘油三酯含量呈胁迫时间依赖性下降。血清谷草转氨酶、谷丙转氨酶、酸性和碱性磷酸酶活力呈上升趋势,并在9 h达到峰值。以上生化指标在胁迫复苏组有所恢复,表明AC+WD双重胁迫引起凡纳滨对虾物质代谢紊乱,复苏后机体生理应激和代谢系统发生一系列代偿性调节,且胁迫进程中肝胰腺组织病理损伤特征进一步解释了凡纳滨对虾响应环境联合胁迫的结构基础。【结论】无水保活流通过程中双重胁迫时间依赖性改变凡纳滨对虾生理应激水平和物质代谢,在9 h时可明显造成肝胰腺组织结构损伤,进而影响机体存活。     

光合细菌对养殖水质及凡纳滨对虾抗病力的影响

在凡纳滨对虾养殖环境中人工引入不同浓度的光合细菌,监测氨氮、亚硝酸氮、化学需氧量的变化,15d后测定凡纳滨对虾的AKP、POD、PO、SOD、抗菌、溶菌活力,以及不同光合细菌浓度下凡纳滨对虾的成活率与体重增长率,研究光合细菌对水质和凡纳滨对虾抗病力的影响。结果表明,引入光合细菌可显著降低水体化学需氧量、氨氮含量,并抑制亚硝酸盐氮的产生,提高凡纳滨对虾的抗病力。当光合细菌投放浓度为3×103/mL时,水体中化学需氧量、氨态氮、亚硝酸盐氮含量的均值分别比对照组降低31.59%、43.42%、52.20%,差异显著(P<0.05);对虾的AKP、POD、PO、SOD、抗菌、溶菌活力分别比照组提高31.92%、72.29%、55.56%、31.61%、39.07%、69.51%,差异显著(P<0.05);成活率,体重增长率分别比对照组提高18.67%、34.03%,差异显著(P<0.05)。     

蜕壳素对凡纳滨对虾生长及表观消化率的影响

研究了外源性蜕皮激素对凡纳滨对虾生长和表观消化率的影响，实验时在基础饲料中分别添加0．1％、0．2％、0．4％的两种市售蜕壳素产品，制成6种外源性脱壳素配合饲料，不添加的基础饲料作为对照组，试验在260L玻璃钢循环水养殖系统中，每个剂量组设3个重复，8周生长试验结果表明：市售蜕壳素产品能有效地促进对虾生长，试验结束时，试验组虾体增重分别较对照组增加16．8％、7．52％、5．9％、11．4％、29．07％、16．53％，但是凡纳滨对虾对饲料粗蛋白的表观消化率没有明显地提高，凡纳滨对虾对脂肪的表观消化率较低。推算凡纳滨对虾饲料中最佳蜕皮酮添加量为60mg/kg。     

凡纳滨对虾对虾杆状病毒PCR检测方法的建立及初步应用

根据Gen Bank中公布的对虾杆状病毒(Baculovirus penaei,BP)基因片段序列,设计1对特异性检测引物,建立快速检测凡纳滨对虾(Litopenaeus vannamei)对虾杆状病毒的PCR方法。用该方法对BP阳性虾进行PCR扩增,结果得到380 bp的特异性扩增条带,与实验设计相符,而对白斑综合征病毒(WSSV)、桃拉病毒(TSV)、传染性皮下及造血器官坏死病毒(IHHNV)阳性虾和健康虾的扩增结果为阴性。测序比对结果证实,该PCR方法检测结果准确,最低可检测出约1 pg的病毒DNA。利用建立的PCR方法对来自广东、广西、福建、海南和浙江的2 722份临床病料进行检测,共检出阳性病料133份,表明该PCR方法可用于对虾杆状病毒的临床快速检测。     

蜕壳素对凡纳滨对虾生长及表观消化率的影响

研究了外源性蜕皮激素对凡纳滨对虾生长和表观消化率的影响 ,实验时在基础饲料中分别添加 0 .1%、0 .2 %、0 .4 %的两种市售蜕壳素产品 ,制成 6种外源性脱壳素配合饲料 ,不添加的基础饲料作为对照组 ,试验在 2 6 0L玻璃钢循环水养殖系统中 ,每个剂量组设 3个重复 ,8周生长试验结果表明 :市售蜕壳素产品能有效地促进对虾生长 ,试验结束时 ,试验组虾体增重分别较对照组增加 16 .8%、7.5 2 %、5 .9%、11.4 %、2 9.0 7%、16 .5 3% ,但是凡纳滨对虾对饲料粗蛋白的表观消化率没有明显地提高 ,凡纳滨对虾对脂肪的表观消化率较低。推算凡纳滨对虾饲料中最佳蜕皮酮添加量为 6 0mg/kg。     

凡纳滨对虾潘状幼体厌食症的防治

潘状幼体厌食症是指潘状幼体发育到第2期后,出现摄食突然减少和停食的现象,幼体发病率和死亡率较高。探讨育苗用水处理方法、抗菌素、有益微生物制剂对防治凡纳滨对虾潘状幼体厌食症的效果。结果表明：1）用次氯酸钠、百碘、溴氯海困对育苗用水进行消毒处理没有预防潘状幼体厌食症作用,用甲醛处理水有一定的预防效果,幼体发病率为75.3％,低于对照组的88.2％,差异有统计学意义（P〈0.05）;2）利福平、土霉素、庆大霉素、诺氟沙星、复方新诺明等抗菌药物对潘状幼体厌食症防治效果不佳,除利福平外,其他药物组幼体发病率、存活率与对照组差异无统计学意义（P〉0.05）;3）有益微生物制剂光合细菌、乳酸杆菌、芽孢杆菌、复合活菌制剂EM活菌、虾蟹宝活菌和乐多源活菌对潘状幼体厌食症都有不同程度的预防作用,幼体发病率、存活率与对照组差异有统计学意义（P〈0.05）,以乐多源活菌预防效果最好,幼体发病率仅19.8％,比对照组低63.3％,治疗作用仅乐多源活菌较好,可治愈50.0％的发病幼体,其他活菌治疗效果不佳。建议潘状幼体厌食症应采取处理水和使用有益微生物制剂相结合方法进行防治。     

抗菌肽对凡纳滨对虾生长和机体免疫的影响

基础饲料(对照组)中添加10g/kg抗菌肽制剂喂养体重0.10±0.01g、体长2.17±0.11cm的凡纳滨对虾(Penaeus vannamei)30d,进行10d的水浴攻毒(鳗弧菌10~8/mL),探讨饲料中添加抗菌肽对凡纳滨虾生长、成活率、免疫保护率,以及肌肉中溶菌酶活性、超氧化物歧化酶活性、总抗氧化能力的影响。结果表明:饲料中添加抗菌肽可显著提高凡纳滨对虾相对增重率、成活率和对致病菌的免疫保护率(P<0.05),但对饲料系数无显著影响(P>0.05);未受外界微生物刺激时,饲料中添加抗菌肽对凡纳滨对虾总抗氧化能力有促进作用(P<0.05),受外界微生物刺激后,饲料中添加抗菌肽喂养凡纳滨对虾可提高对虾超氧化物歧化酶活性(P<0.05)和总抗氧化能力(P<0.01)。因此饲料中添加抗菌肽喂养凡纳滨对虾可提高其机体非特异性免疫。     

Effect of Bioactive Peptides(BPs) on the Development of Pacific White Shrimp(Litopenaeus vannamei Boone, 1931)

The present study was conducted to evaluate the feasibility of replacing fish meal(FM) with bioactive peptides(BPs) in diet of white shrimp(Litopenaeus vannamei). The changes in growth performance, body composition, non-specific immunity, and water quality were examined after the shrimp were fed four diets, in which 0%(control), 33.3%, 66.7% and 100% of FM was replaced by BPs, respectively. The groups were designated as Con, 1/3BPs, 2/3BPs, and 3/3BPs. A total of 720 shrimp with an initial body weight of 1.46 ± 0.78 g were fed the experimental diets for 56 days. The results revealed that: 1) the weight gain rate(WGR) in 1/3BPs, 2/3BPs, and 3/3BPs was significantly higher than that in Con(P 0.05), while no significant difference was found on survival rate and feed conversion ratio(FCR); 2) the whole-body crude protein(CP) and crude lipids(CL) were significantly different among groups, while there was no significant difference between crude ash and phosphorus contents; 3) the levels of acid phosphatase(ACP), lysozyme(LZM), superoxide dismutase(SOD), phenol oxidase(PO) and bactericidal activity increased significantly with the inclusion of BPs; 4) in terms of water quality, no significant difference was found in p H and dissolved oxygen among diets during the whole experimental period. Moreover, even though nitrite and ammonium levels tended to increase with time, there was no significant difference among groups. The results indicated that BPs is an applicable alternative of protein source, which can substitute FM in the diets of L. vannamei; it is able to effectively promote growth performance and improve immunity. Moreover, BPs in the diets had no negative impact on water quality.     

Production of Pacific White Shrimp Polycultured with Swimming Crab at Different Densities,and Nutrient Budget in the Enclosure System

This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(initial weight,0.012 g)were cultured at a density of 45 shrimp m^-2,and juvenile crabs(initial weight,0.024 g)were cultured at five densities of 0,3,6,9,and 12 crabs m^-2.The treatments were grouped as C0S45,C3S45,C6S45,C9S45,and C12S45,respectively.Water quality parameters,growth of shrimp and crabs,and nitrogen and phosphorus budget were measured.The results indicated that the shrimp performances in polyculture treatments C3S45 and C6S45 were superior to those in the crab-free treatment(C0S45).The crab in treatments C3S45 and C6S45 exhibited a significantly higher final mean weight and carapace width/length than those in treatments C9S45 and C12S45.The final size and survival of crabs had a negative correlation with the increasing crab stocking density.The contents of total phos-phorus and total nitrogen and the comprehensive contamination index values were higher in the C9S45 and C12S45 treatments than in the other treatments.The conversion ratios of nitrogen for crab and shrimp growth in treatment C3S45 were significantly higher than those in the crab-free treatment.These findings indicate that polyculturing shrimp with crabs at suitable densities can improve productivity,profitability,nutrient utilization,and the environmental quality.From the 60-day treatments,the optimal culture densi-ties were 3-6 crabs m^-2 and 45 shrimps m^-2.     

Isolation of Enterococcus faecium with Feeding Attractant Function from Pacific White Shrimp ( Litopenaeus vannamei ) Intestine

In the present study, we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei) intestine. Using conventional and molecular methods, we identified the bacterium as Enterococcus faecium, and found it had the function of feeding attractant and could inhibit the development of Vibrio parahaemolyticus(zone of inhibition: 14 mm). The attractant effect of its fermentation broth is significantly better than that of the chemical attractant trimethylamine oxide(TMAO)(P 0.05), and is equivalent to that of dimethyl-beta-propiothetin(DMPT) based on the feeding behavior of shrimp. High performance liquid chromatography(HPLC) analysis suggested that inosine-5'-monophosphate(IMP) may be a component of the attractant. A biosecurity evaluation revealed a negative result in hemolytic assays, and no shrimp mortality was resulted from SC-01 fermentation broth challenge. Feeding trials(60 days) indicated that the SC-01 fermentation broth(viable counts: 5.7×10~9 cfu mL~(-1)) could improve feed intake, weight gain rate(WGR) and specific growth rate(SGR), and decrease the count of Vibrio sp. in the intestine of shrimp.     

切除眼柄对凡纳滨对虾亲虾卵巢、肝胰腺、血清生化组成的影响

为探讨眼柄切除对凡纳滨对虾性成熟的促进机理,采用镊烫法切除雌性凡纳滨对虾单侧眼柄,并测量肝胰腺指数和性腺指数,测定卵巢、肝胰腺和血清中生化组分含量的变化。结果表明,切除眼柄7 d后,1)肝胰腺指数降低,性腺指数上升,差异均有统计学意义(P0.05);2)卵巢、肝胰腺中总蛋白含量增加,差异有统计学意义(P0.05),血清中总蛋白含量无明显改变(P0.05);3)卵巢和血清中胆固醇含量增加,肝胰腺中胆固醇含量降低,差异均有统计学意义(P0.05);4)血清中钙离子和无机磷含量增加,差异有统计学意义(P0.05)。切除眼柄后,卵巢和肝胰腺中卵黄蛋白原等营养物质大量合成,肝胰腺中的总蛋白、胆固醇等营养物质先转移至血淋巴,再转移至卵巢,从而促进性腺的成熟。     

凡纳滨对虾肠道上皮细胞微胞子虫PCR检测方法的建立与应用

根据Gen Bank中对虾肠道上皮细胞微胞子虫(Enterocytozoon hepatopenaei,EHP)的基因保守序列,设计一对特异性引物,通过优化PCR扩增条件,建立快速检测凡纳滨对虾(Litopenaeus vannamei)EHP的PCR方法。用该方法对EHP阳性虾进行PCR扩增,得到与实验设计相符的330 bp特异性扩增条带,而对白斑综合症病毒(WSSV)、桃拉病毒(TSV)、传染性皮下及造血器官坏死病毒(IHHNV)、对虾杆状病毒(BP)、"棉花虾"微孢子虫、黏孢子虫的阳性虾,以及健康虾的扩增结果为阴性。测序比对发现,PCR产物序列与Gen Bank EHP基因序列的同源性为99.8%,表明该PCR方法检测结果准确。敏感性试验表明,该方法最低可检测出约100 fg的EHP质粒DNA。用该PCR方法检测广东、广西、江苏、山东、海南等地的755份临床样品,共检出阳性样品21份。该PCR方法可用于凡纳滨对虾EHP的快速检测。     

大黄对凡纳滨对虾生长和非特异性免疫指标的影响

在凡纳滨对虾饲料中分别添加大黄0、0.5、1.0、5.0、10.0和20.0g/kg,研究大黄对凡纳滨对虾(初始体重为0.34±0.004g)生长及非特异性免疫指标的影响。结果表明,大黄对凡纳滨对虾成活率、增重率、特定生长率、饲料系数、蛋白质效率和蛋白质累积率的影响不显著(P>0.05),对全虾和尾肌肉的灰分、脂肪和粗蛋白含量影响显著,全虾的粗蛋白和粗脂肪含量以1.0g/kg组最高(P<0.05),对凡纳滨对虾血清碱性磷酸酶、酸性磷酸酶、酚氧化酶、超氧化物歧化酶、溶菌酶以及血清总蛋白量等的影响显著,溶菌酶活性以1.0g/kg组最高(P<0.05);细菌感染实验中以1.0g/kg组存活率最高(P<0.05)。以非特异性免疫反应指标及感染实验存活率为指标,凡纳滨对虾饲料中大黄的适宜添加量为1.0g/kg。     

微囊藻毒素对凡纳滨对虾免疫相关酶活力的影响

通过毒性注射实验,探究微囊藻毒素(MC-LR)对凡纳滨对虾(Litopenaeus Vannamei)肝脏免疫相关酶活力的影响。结果表明,注射MC-LR后,凡纳滨对虾肝胰脏组织的超氧化歧化酶、谷胱甘肽过氧化酶、过氧化物酶、酸性磷酸酶、碱性磷酸酶和溶菌酶的酶活力呈先增大后减小的变化趋势。超氧化歧化酶、谷胱甘肽过氧化酶和过氧化物酶活力在对虾注射MC-LR 4 h后达到峰值,比对照组分别增加了15.62%、18.76%和32.86%,随后酶活力逐渐减小;而酸性磷酸酶和碱性磷酸酶酶活力在对虾注射MC-LR 2 h后即显著增加,比对照组分别增加了25.02%和37.99%,随后酶活力逐渐减小;溶菌酶在对虾注射MC-LR后8 h达到最大值,比对照组增加了33.57%,随后酶活力逐渐减小。MC-LR能显著影响凡纳滨对虾的免疫相关酶活力(P0.05),引起凡纳滨对虾的应激反应和抑制它们的免疫相关酶活力。     

Effects of Hypoxia on Dopamine Concentration and the Immune Response of White Shrimp （Litopenaeus vannamei）

Effects of hypoxia on the dopamine concentration and the immune response of White Shrimp Litopenaeus vannamei were studied. The results showed that hypoxia had significant effects on the concentration of dopamine (DA) in the haemolymph, haemocyte count, phenoloxidase activity, phagocytic activity of haemocytes and bacteriolytic and antibacterial activity in the haemolvmph (P<0.05). The concentration of the dopamine in haemolymph reached its maximum in the 3.0 and 1.5mgL-1 DO groups at 12h and 6h, and then returned to normal after 24h and 12h, respectively. All immune parameters decreased with the reduction of dissolved oxygen. Total haemocyte count (THC), the hyaline cells and semi-granular cells in the 3.0mgL-1 DO group became stable after 12h,while granular cells did so after 24h, The THC and different haemocyte count (DHC) in the 1.5mgL-1 DO group became stable alter 24h. Phenoloxidase activity and bacteriolytic activity in the 3.0 and 1.5mgL-1 DO groups reached their stable levels after 24 h and 12 h respectively, while phagocytic activity and antibacterial activity became stable after 24 and 12, and 36 and 24 It, respec-tively. It was also indicated that the changes of dopamine concentrations in haemolymph, haemocyte count and phenoloxidase activ-ity were obviously related to the exposure time under hypoxic conditions.