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81.
The effects of two probiotic feeds containing two and three bacterial isolates were evaluated on the growth performance of New Zealand abalone (Haliotis iris). Probiotic bacteria were isolated from the guts of healthy adult abalone. The isolates were screened qualitatively and quantitatively according to their ability to hydrolyse nutrients (i.e. proteins, starch and alginate), produce acid and resist bile salts. Based on the screening results, we developed a multi-strain conglomerate of 2- and 3- probiotic bacterial strains that were supplemented into a commercial abalone feed to use in our experiments. The 2-probiotic conglomerate consisted of Exiguobacterium JHEb1 and Vibrio JH1, and the 3-probiotic conglomerate consisted of Exiguobacterium JHEb1, Vibrio JH1 and Enterococcus JHLDc. The probiotic feeding trial involved abalone juveniles (20–30 mm in maximum shell length). Both probiotic feeds significantly improved abalone growth compared to that of the unsupplemented feed. The 3-probiotic supplemented feed produced a significant shell length increase of 20.9%, a wet weight gain of 19.8% and a five-fold reduction in mortality compared to the controls. The 2-probiotic supplemented feed resulted in significant increases in shell length (15.4%) and reduced mortality (five-fold), but not in weight gain, compared to controls.  相似文献   
82.
Experiments were conducted to test the effect of a range of chemicals on larval responses in swimming behaviour, attachment and metamorphosis of the black-footed abalone (Haliotis iris). The effect of antibiotics on larval survival was first tested within negative (filtered seawater) and positive (GABA at 10?5, 10?4 and 10?3 mol L?1) control assays over 3 days. This experiment corroborated the effectiveness of using antibiotics to improve survival of larvae without obvious synergistic interactions with the GABA inducer or confounding effects of potential bacterial interactions. Chemical treatments (acetylcholine, potassium chloride, dopamine and glutamine) were then tested at various concentrations for their ability to modulate swimming behaviour and induce larval attachment and metamorphosis over 14 days. Generally, larval state shifted from swimming to attached, and from attached to metamorphosed, in the control and treatments over time. However, the peak percentage of attached and metamorphosed larvae varied in time among chemicals and concentrations. While overall percent metamorphosis was minimally enhanced after 14 days of exposure to some chemical treatments at certain concentrations, all treatments displayed significant capacities to down-regulate larval swimming and induce early attachment and metamorphosis. Mortality was recorded throughout the duration of the experiment, and was generally low (<20%) across controls and most treatments for exposures of less than 12 days. Interpretations of specific results from this study are used to elucidate neurophysiological control of larval activities for this abalone species. Comparisons with other marine invertebrates highlight the specificities of chemical cues and endogenous regulatory mechanisms across relatively closely related taxa.  相似文献   
83.
针对福建等海域养殖皱纹盘鲍度夏死亡率高的现象,试验研究了不同盐度、温度和溶解氧条件,对皱纹盘鲍幼鲍和1龄鲍死亡率的影响,并根据试验结果设定了皱纹盘鲍海上养殖盐度、温度和溶解氧预警阈值。结果表明:低盐胁迫对皱纹盘鲍的死亡率影响显著,在水温24~27℃时,盐度20是幼鲍和1龄鲍试验组和对照组死亡率有显著差异的临界点,盐度预警阈值为22;高温胁迫对皱纹盘鲍的死亡率影响显著,温度28℃是幼鲍和1龄鲍试验组和对照组死亡率有显著差异的临界点,温度预警阈值为27℃;皱纹盘鲍有较强的耐低氧能力,在水温26℃,盐度为30,溶解氧低于2.0mg/L时,开始大量死亡,溶解氧预警阈值为3.5mg/L;高温胁迫和低盐胁迫对皱纹盘鲍的死亡率有显著的交互作用,温度升高,低盐耐受能力下降。  相似文献   
84.
A 240-day growth experiment in a re-circulating water system was conducted to investigate the effects of dietary menadione on the growth and antioxidant responses of abalone Haliotis discus hannai Ino. Triplicate groups of juvenile abalone (initial weight: 1.19 ± 0.01 g; shell length: 19.23 ± 0.01 mm) were fed to satiation with 3 semi-purified diets containing 0, 10, and 1 000 mg menadione sodium bisulfite (MSB)/kg, respectively. Results show that there were no significant differences in the rate of weight gain or in the daily increment in shell length of abalone among different treatments. Activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR) in viscera were significantly decreased with dietary menadione. However, activities of these enzymes except for GPX in muscle were increased. Therefore, antioxidant responses of abalone were increased in muscle and decreased in viscera by dietary menadione.  相似文献   
85.
Tag‐recapture studies revealed differences in the growth rate of Haliotis iris between headlands and bays separated by as little as 200 m. Individuals off headlands had a significantly higher incremental growth and reached a higher maximum size than those in bays. These results were consistent with observations of the size composition of H. iris which showed that few individuals of harvestable size (> 125 mm shell length) were found in bays. Differences in the growth rate of H. iris may account for the apparent differences in the size at onset of maturity: individuals off headlands, and from a fast‐growing population off Wellington, reached reproductive maturity at a smaller size compared with those in bays. Yield‐per‐recruit modelling showed greater yields from headlands than bays, but egg‐per‐recruit modelling revealed more egg production was conserved in bays than off headlands. Yields could be increased from bays by decreasing the minimum size to 110 mm. Egg‐ and yield‐per‐recruit models were sensitive to the natural mortality rate (M = 0.03, 0.05 and 0.10 compared). The results show that parameters important in the management of commercial fisheries for abalone can vary over small distances: such variation should be incorporated in management strategies for abalone fisheries.  相似文献   
86.
以皱纹盘鲍(Haliotis discus hannai Ino)中国群体与日本群体的杂交(WJ)子1代为母本,在汕头养殖并选育了3代的“S”群体为父本,建立三元杂交组合(WJ-S)并尝试了海区围堰全生态模式养殖。以同期繁育的皱纹盘鲍中国群体与日本群体的杂交子1代(WJ-F1)为对照,比较 WJ-S 与对照组在生长速度和存活率等方面的差异。结果表明,在苗种和养成阶段, WJ-S 的度夏存活率均显著高于同期对照;从围口壳幼体到养成阶段, WJ-S组的平均壳长大于同期对照,养成阶段WJ-S组的全湿重显著高于对照,表明皱纹盘鲍三元杂交子代的生长速度显著高于对照;从苗种到养成阶段的3次分选数据表明, WJ-S的大规格子代比例均高于对照,小规格苗种比率则低于对照,表明三元杂交鲍苗种的生长速度优于对照;在青岛崂山海区全生态养殖18个月,三元杂交组已达商品规格。上述结果表明,在二元杂交的基础上加入第三方亲本 S 制备的三元杂交皱纹盘鲍,在生长速度、夏季高水温期的存活率等方面都较皱纹盘鲍“中-日”杂交子代显著提高。  相似文献   
87.
气象条件对铁饼比赛成绩的影响及其回归方程的建立   总被引:2,自引:0,他引:2  
铁饼投掷成绩是由运动员的身体素质、专项技术能力和周围的气象条件等因素决定的,而气象条件则影响着比赛运动员技术水平的发挥和心理状况。该文主要利用国家体育总局提供的1998—2002年国内大型体育比赛中的铁饼比赛成绩和气象资料,分析了气象条件与男子(女子)铁饼平均成绩、男子(女子)铁饼个人成绩的关系,发现气象要素中气压对铁饼比赛影响较大,气压高有利于男女运动员取得好成绩;风速对运动员铁饼比赛成绩的相关系数为负值,风速大,会破坏铁饼飞行的稳定性,影响比赛成绩;当气温小于25℃时,气温高较利于比赛取得好成绩;当气温大于25℃时,气温低利于比赛取得好成绩;空气湿度对铁饼比赛影响不大,但当温度偏高时,湿度偏高会对比赛有不利影响。并根据气象数据和体育成绩利用多元线性回归分析建立了回归方程。  相似文献   
88.
硒结合蛋白1(selenium-binding protein 1,SBP1)是一种高度保守的蛋白,广泛参与了机体的多个理化过程。本研究首次获得了杂色鲍(Haliotis diversicolor)SBP1基因的全长c DNA序列2269 bp,并命名为Hd SBP1,ORF为1494 bp,共编码497个氨基酸。荧光定量PCR结果显示,Hd SBP1基因在杂色鲍各组织中均有表达,其中在鳃和肾中的表达量相对较高。缺氧处理后,Hd SBP1在鳃组织和血细胞中的表达量分别在处理24 h和192 h后显著升高(P0.05);高温应激之后,在鳃组织中,Hd SBP1的表达量在第1时相与第3时相显著升高(P0.05),而在血细胞中只有在第3时相表现出显著性差异;缺氧和高温联合应激之后,鳃组织中Hd SBP1的表达量在192 h显著上调(P0.05),在血细胞中Hd SBP1的表达量在0 h、4 h和24 h时均显著升高(P0.05);副溶血弧菌注射感染之后,在鳃组织中Hd SBP1的表达量在6 h和24 h时显著性上调(P0.05),而血细胞中Hd SBP1基因的表达量在每个时相的实验组都显著高于对照组(P0.05)。以上不同的应激条件均会导致Hd SBP1在不同组织中的表达量的显著变化,说明Hd SBP1在杂色鲍的免疫反应中可能扮演着重要的角色。  相似文献   
89.
Phenoloxidases(POs)are a group of copper proteins including tyrosinase,catecholase and laccase,which play crucial roles in the innate immune response of mollusks.In this research,POs were studied in cultured mollusk species,including scallop Chla-mys farreri,abalone Haliotis discus hannai and clam Scapharca subcrenata.The POs were isolated from hemocytes using linear-gradient native-PAGE combined with catechol staining.The PO activities and their characters were investigated.The molecular mass of PO in C.farreri was 576 kDa,and it was 228 kDa in H.discus hannai.In S.subcrenata,four POs were detected and their mole-cular masses were 391 kDa,206 kDa,174 kDa and<67 kDa,which were named as 391-PO,206-PO,174-PO and s-PO,respectively.Ki-netic analyses indicated that all of the POs,except for 391-PO had higher affinity to L-DOPA and catechol than to hydroquinone and dopamine.However,all of the POs failed to oxidize tyrosine.The effects of divalent metal ions on POs’activities were assayed,in-cluding Fe2+,Mg2+,Zn2+,Mn2+,Cu2+and Ca2+from FeCl2,MgSO4,ZnSO4,MnCl2,CuSO4and CaCl2.The POs were inhibited by Fe2+at all determined concentrations.Additionally,the inhibition assay showed that all of the POs were inhibited by cysteine,ascorbic acid,sodium sulfite,citric acid,ethylenediaminetetraacetic acid disodium(EDTA)and sodium diethyldithiocarbamate(DETC).The inhibition effects of critric acid and EDTA are dose-dependent.H.discus hannai PO and 391-PO were slightly inhibited by sodium azide,and H.discus hannai PO,391-PO and 174-PO were slightly inhibited by thiourea.In conclusion,the POs in the three cultured mollusks are copper-containing laccase-type phenoloxidases with similar biochemical characteristics even though their molecular masses are different.  相似文献   
90.
鲍育苗期病害的防治研究──Ⅰ.福尔马林的防治试验   总被引:1,自引:0,他引:1  
在皱纹盘鲍HaliotisdiscusHannai育苗期间,幼鲍用福尔马林药浴,对原生动物、线虫、桡足类等引起的病害防治有显著效果。当浓度为5~20g/m3,浸浴6~12h能杀死附着板上的原生动物、线虫和部分桡足类,同时也有强的杀菌作用,而对幼鲍及饵料硅藻的发育和活力均没影响。  相似文献   
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