共查询到20条相似文献，搜索用时 125 毫秒
1.
实验饲料中以酵母硒形式分别添加硒0(对照)、0.2、0.4、0.6、0.8和1.0 mg/kg(饲料中硒总含量分别为0.11、0.23、0.43、0.66、0.87、1.09 mg/kg), 配制成6组半纯化饲料, 投喂初始体质量为(0.27±0.01) g的中华绒螯蟹(Eriocheir sinensis)幼蟹, 进行为期6周的饲养实验。结果表明, 当饲料硒的添加量为0.4 mg/kg时, 幼蟹的增重率、存活率及全蟹体粗蛋白质含量均显著高于其他各组(P<0.05)。同时, 随着饲料中硒水平的提高, 幼蟹的肝胰腺和肌肉中硒含量也相应显著升高(P<0.05)。肝胰腺和血清中的谷胱甘肽过氧化物酶活性则随着硒添加量的提高而呈现出先升高后降低的趋势, 当硒添加量为0.4 mg/kg时达到最高, 且显著高于添加量为0.8 和1.0 mg/kg的饲料组(P<0.05)。幼蟹血清和肝胰腺中丙二醛含量随着硒添加量的增加而呈现出先降低而后升高的趋势, 其中0.4 mg/kg饲料组最低, 并显著低于对照组和1.0 mg/kg饲料组(P<0.05)。硒添加量小于或等于0.6 mg/kg的各组, 其还原型谷胱甘肽含量显著低于0.8和1.0 mg/kg饲料组(P<0.05)。结果提示, 饲料中适量添加硒(0.4~0.6 mg/kg, 硒总含量为0.43~0.66 mg/kg)能促进中华绒螯蟹幼蟹的生长, 提高饲料蛋白质效率和抗氧化能力。以血清谷胱甘肽过氧化物酶活性为判据, 采用二次回归模型进行拟合发现, 当饲料中硒添加量为0.51 mg/kg (饲料中硒总含量0.59 mg/kg)时, 中华绒螯蟹幼蟹可获得最佳的生长效果, 因此建议中华绒螯蟹幼蟹饲料硒的适宜添加量为0.4~0.6 mg/kg。 相似文献
2.
利用已经发表的11对胭脂鱼多态性微卫星标记, 对长江中上游胭脂鱼(Myxocyprinus asiaticus)增殖放流效果进行评估。结果表明, 5个胭脂鱼养殖场内所有的149尾繁殖亲本和长江中上游采集的65尾胭脂鱼中共观测到140个等位基因, 其观测杂合度和期望杂合度的平均值(范围)分别为0.771(0.519~0.906)和0.759(0.469~0.894), 多态信息含量(范围)为0.726(0.392~0.882)。通过软件Cervus统计得到, 11个微卫星座位累计排除率为99.998 3%, 并且在长江中上游采集的65个样本中, 11个样本与养殖场内繁殖亲本确定存在亲子关系, 据此确定这11尾为增殖放流的胭脂鱼, 并由此推算增殖放流的胭脂鱼对长江中上游野生群体的贡献量为16.92%。研究结果表明, 增殖放流是实现胭脂鱼野生种群资源恢复的有效途径。 相似文献
3.
建立牙鲆(Paralichthys olivaceus)雌核发育近交系和杂交系, 以两性生殖家系作为对照组, 对3个群体的遗传特征和生长进行比较。结果表明, 雌核发育近交系、杂交系和对照组的等位基因数分别为41、55、78, 平均等位基因数为1.7、2.3、3.3, 平均观测杂合度为0.419 2、0.654 9、0.916 7, 雌核发育杂交系的上述参数明显高于近交系, 但低于对照组。3个群体的平均纯合度分别为0.580 7、0.345 1、0.083 3, 个体之间的遗传相似度分别为0.831 2、0.826 1、0.672 7, 杂交系小于近交系, 但明显高于对照组(P<0.05)。在生长方面, 雌核发育杂交系比近交系和对照组生长快, 差异极显著(P<0.01)。从结果可以看出, 雌核发育杂交系具有比近交系高的杂合度, 但具有与近交系相似的遗传相似度; 生长上比近交系明显快, 表现出明显的杂交优势。结论认为雌核发育家系杂交方法可以作为一种育种手段, 用于发挥杂交优势和提高遗传相似度。 相似文献
4.
采用人工创伤的方法剪断仿刺参(Apostichopus japonicus)体腔背部的纵肌带, 然后缝合切口处的体壁, 将其在添加抗生素(100 IU/mL的青霉素和100 μg/mL的链霉素)的海水中继续饲养。通过形态学和组织学方法对仿刺参纵肌带再生过程中的结构变化进行了观察。形态学结果显示, 创伤后0 h, 由于纵肌带的收缩, 断端出现0.5~1 cm的间隙; 创伤15 d, 创伤处出现乳白色絮状组织, 暂命名为肌前组织; 创伤30~45 d时, 肌前组织逐渐增厚并将断端肌肉组织连接起来; 创伤60~90 d, 肌前组织已转化成纵肌带, 并且其厚度增至正常纵肌带的1/2; 创伤后110~130 d, 新生纵肌带进一步增粗, 形态上与未创伤处组织没有区别, 只是直径略小一些; 创伤150 d, 再生的纵肌带厚度同正常状态。组织学结果显示, 创伤后15 d, 在损伤处出现结缔组织及单个的肌纤维, 形成一条不规则的细长条带, 即肌前组织; 创伤后30~45 d, 肌前组织中肌细胞数量大量增加, 并与体壁间形成一些“桥状”连接; 创伤后60~90 d, 肌前组织几乎被肌纤维占据, 且“桥状”连接数量增加, 此时肌前组织已转化为肌肉带(纵肌带); 创伤后110~130 d, 新生肌纤维数量大量增加, 和体壁相连的“桥状”连接数量减少, 创伤150 d, 新生的纵肌带基本达到正常的结构, 且“桥状”连接消失。分析认为仿刺参纵肌带具有较强的再生能力, 且新生的肌细胞来源于体壁结缔组织细胞和体腔上皮细胞。 相似文献
5.
以中国水产科学研究院北戴河中心实验站养殖的双单倍体(DH)牙鲆(Paralichthys olivaceus)作为亲鱼, 采用冷休克方法抑制第二极体排出, 建立牙鲆克隆家系。以普通牙鲆的一个家系作为对照组, 在同样饲养条件下进行培育。实验组和对照组均为2+ 龄鱼, 克隆家系随机抽取5尾, 体质量(1 398±88) g; 普通群体随机抽取10尾, 体质量(1 749±125) g。分别采集血液进行血液生理和生化指标的比较分析。结果表明: 1) 克隆牙鲆的红细胞数量(RBC)、血红蛋白数量(HGB)、平均血红蛋白量(MCH)、红细胞压积(HCT)极显著低于普通牙鲆(P<0.01), 而在其他血液生理指标上二者没有显著性差异(P>0.05); 2) 克隆牙鲆在白球比(ALB/GLB)、谷草转氨酶/谷丙转氨酶(AST/ALT)比值、谷草转氨酶(AST) 3个指标上显著高于普通牙鲆(P<0.05), 其中AST差异达到极显著水平(P<0.01), 而碱性磷酸酶(ALP)、总胆固醇(CHO)、尿素氮(BUN) 3项指标, 克隆牙鲆极显著低于普通牙鲆(P<0.01)。克隆牙鲆血液生理指标的平均变异系数为5.50%, 普通牙鲆的则为9.21%, 其中克隆牙鲆红细胞平均体积(MCV)的变异系数仅为1.52%。克隆牙鲆血液生化指标的变异系数平均为10.56%, 普通牙鲆的则为27.23%, 达到克隆牙鲆的2.58倍。结果证实, 克隆牙鲆个体间的一致性较好, 作为指标生物, 效果优于普通牙鲆等海产鱼类。 相似文献
6.
根据2011年3月、5月、7月、9月和12月在海州湾及其邻近海域进行的5个航次底拖网调查资料, 对5种主要鱼类[包括六丝钝尾虾虎鱼(Amblychaeturichthys hexanema)、短鳍 (Callionymus kitaharae)、长吻红舌鳎(Cynoglossus lighti)、方氏云鳚(Enedrias fangi)和棘头梅童鱼(Collichthys lucidus)]的种群参数进行了估算。结果表明, 在这5种鱼类中, 生长系数(k)最高的是方氏云鳚(0.76), 其次是六丝钝尾虾虎鱼(0.70), 其他3种鱼类的生长系数均小于0.60; 总死亡系数(Z)最高的鱼种是方氏云鳚(4.62), 其次是长吻红舌鳎(3.55)、六丝钝尾虾虎鱼(2.99)和棘头梅童鱼(2.99), 短鳍 的总死亡率最低(1.60); 长吻红舌鳎、方氏云鳚和棘头梅童鱼的开发率(E)最高, 分别为0.74、0.74和0.73, 此外, 六丝钝尾虾虎鱼的开发率也较高(E=0.60), 而仅有短鳍 的开发率较低(E=0.43); 长吻红舌鳎、方氏云鳚和棘头梅童鱼的平均选择体长(L50)较大, 分别为145.2、107.1和98.7 mm, 而六丝钝尾虾虎鱼和短鳍 的平均选择体长较小, 分别为60.0 mm和48.4 mm; 通过计算方氏云鳚和棘头梅童鱼2种鱼类的生长表现指数(f′), 并与其他学者的研究结果相比较, 发现同一鱼种的生长表现指数随着栖息海域纬度的降低而呈上升趋势。 相似文献
7.
基于家系选育技术开展了大菱鲆(Scophthalmus maximus)抗鳗弧菌病选育研究, 从2010年构建的37个选育二代家系中选择成活率高的30个家系进行鳗弧菌(Vibrio anguillarum)感染实验, 开展对鳗弧菌的抗病性研究。结果表明, 不同家系间抗鳗弧菌感染能力存在着显著差异(P＜0.05); 30个家系中, 鳗弧菌感染后, 12个家系的存活率达到65% 以上, 其余家系的存活率则低于65%; 通过bCOX回归分析, 计算各家系的优势比, 优势比最高的5个家系的存活率达到65% 以上; 对各家系的成活率、优势比和死亡历时差4项指标进行聚类分析, 优势比最高且存活率达到65% 以上的5个家系聚为一类。综合感染家系的高成活率、高优势比以及聚类分析的结果, 选育出5个抗病力较强的优良家系。选育出的抗病力较强的家系可做为抗鳗弧菌选育的核心育种群体, 为抗鳗弧菌病的传代选育奠定良好的基础。 相似文献
8.
实验所用翘嘴鳜(♀, Siniperca chuatsi) 2~3龄, 体质量1 000~1 500 g; 斑鳜(♂, Siniperca scherzeri Steindachner)1~2龄, 体质量300~500 g。于繁殖季节选取成熟度好的亲鱼以促黄体素释放激素类似物(LHRH-A2)、绒毛膜促性腺激素(HCG)和马来酸地欧酮(DOM)进行催产。通过筛选D-15、D-17、Ringer液 和 M-Hank’s液4种稀释液和二甲基亚砜 (DMSO)、 甘油(Gly)、乙二醇 (EG)、1,2-丙二醇 (PG)和二甲基甲酰胺 (DMF)5种抗冻剂, 发现DMSO和D-17分别是优选的抗冻剂和稀释液。以D-17作为斑鳜精子的稀释液, 按照1︰3(精液︰稀释液)体积比稀释, 添加10%体积的DMSO作为抗冻剂, 按照三步冷冻法超低温冷冻保存, 37℃水浴解冻的斑鳜精子, 经CASA分析精子活率为(83.26±18.20)%, SCGE检测表明70%以上的精子核DNA不会发生损伤; FCM分析表明26.74%的解冻精子有完整的细胞膜且线粒体功能正常; 用冷冻复苏斑鳜精子与翘嘴鳜精卵进行人工授精, 最高受精率(39.6±6.5)%, 温度24~28℃孵化时间38 h, 孵化后的鱼苗发育正常, 开口1周以后的鱼苗全长(1.346±0.255 ) cm, 体高(0.438±0.103) cm, 体质量(0.045±0.020) g。鲜精受精鱼苗和冻精受精鱼苗在开口后1周的生长没有显著差异。因此认为D-17+10% DMSO可用于斑鳜精液的超低温冷冻保存。本研究将有助于斑鳜种质资源的收集保存和冷冻保存的斑鳜精液在翘嘴鳜(♀)×斑鳜(♂)杂交中的应用。 相似文献
9.
选用750尾初体质量为(114.2 ± 6.5) g的大菱鲆 (Scophthalmus maximus L.), 随机分成5组, 每组3个重复, 每重复50尾鱼, 分别投喂在高脂基础饲料中添加0(D-0)、120 (D-120)、240(D-240)、480 (D-480)和960 mg/kg (D-960) 的DL-α-生育酚醋酸酯5种试验饲料养殖110 d, 考察维生素E(VE)对高脂饲料养殖大菱鲆生长、脂类代谢和抗氧化性能的影响。结果表明, D-240组大菱鲆末均质量最高, 且显著高于D-0组(对照组)(P<0.05), 与其他组差异不显著(P>0.05); D-120组和D-240组饲料系数显著低于D-0组(P<0.05), 但蛋白质效率显著高于D-0组(P<0.05)。D-0组和D-960组血清总胆固醇、甘油三酯、低密度脂蛋白胆固醇和谷丙转氨酶显著高于其他各组(P<0.05), 而D-0组和D-960组高密度脂蛋白胆固醇则显著低于其他各组(P<0.05); 随着饲料VE添加水平的增加, 大菱鲆肝脂蛋白脂酶(LPL)活性有降低的趋势; 脂肪酸合成酶(FAS)活性, 有先增加后降低的趋势。大菱鲆肝总抗氧化酶、超级氧化歧化酶和过氧化氢酶活性, 均随VE添加水平的升高有先升高后下降的趋势, 而丙二醛含量的变化趋势则相反; 随着饲料VE水平的增加, 大菱鲆肝VE积累量有显著升高的趋势(P<0.05), 肌肉VE的积累量先升高后恒定在一个水平。综上所述, 在高脂饲料中添加适量的维生素E (有效含量124~243 mg/kg) 能改善大菱鲆生长性能、饲料利用效率、鱼肝体指数、脏体指数, 调节和改善血脂代谢, 可调控机体脂肪代谢酶活性, 提高机体组织VE积累量和肝抗氧化功能。本研究旨在通过考察添加不同水平的VE对高脂胁迫下大菱鲆生长、脂类代谢酶、抗氧化能力的影响, 为VE在高脂胁迫下的合理使用及以VE营养调控鱼类脂肪代谢和改善抗氧化功能提供参考依据。 相似文献
10.
以鱼油和玉米油作为脂肪源, 配制4种等氮饲料(蛋白含量38%, 脂肪含量12%~13%), 使脂肪酸中高度不饱和脂肪酸(n-3HUFA)的比例分别达3.1%、2.5%、1.9%、1.3%(分别简称SL1、SL2、SL3和SL4), 以其饲喂处于性腺发育Ⅲ期的施氏鲟(Acipenser schrenckii)亲鱼5个月, 研究不饱和脂肪酸对其繁殖性能及性类固醇激素水平变化的影响。结果表明, 经过 5个月养殖, 施氏鲟亲鱼平均体质量增加14.5%, 经过低温刺激及升温处理至产前体质量下降6.8%, 各组之间差异不显著(P>0.05); 饲料中n-3HUFA和n-3PUFA水平对繁殖性能有不同程度的影响, SL1组和SL2组亲鱼的成熟度和仔鱼成活率高于SL3和SL4组, 而仔鱼畸形率显著低于SL3和SL4组(P<0.05); SL1组极化卵卵径显著高于其他组(P<0.05), 平均产卵量高于其他组, 但各组之间差异不显著(P>0.05); 各组之间的受精率、孵化率差异不显著(P<0.05); 各饲料组间血清E2和血清T含量差异不显著(P>0.05)。本研究表明, 使用混合鱼油作为饲料脂肪源, 效果好于单一使用鱼油或玉米油, 同时鱼油的需求比例大于玉米油, 建议n-3 HUFA的适宜添加量在2.5%左右, n-3 PUFA最适需要量需要进一步研究。 相似文献
11.
Soil and water interactions and their influence on growth and production in different densities (SD8 & SD16) under zero water exchange were studied in two successive crops of Penaeus monodon in Tamil Nadu, India during 2007 and 2008. Scraping and tilling during pond preparation increased the mineralization rate than scraping only. During crop, there was no significant difference in soil organic carbon and total nitrogen between the SDs. However, as the crop progressed, organic carbon and total nitrogen content of the soil showed significant difference under both the SDs. Between the SDs, nitrate and phosphate content in water significantly differed, whereas the progress of the crop significantly increased both available and total nutrients. Mass balance of nitrogen indicated that applied feed contributed to 97.4–98.5% of input nitrogen, of which nitrogen in sediment accounted for 16.5–27.3%, nitrogen recovery in shrimp was 34.2–43.6% and the nitrogen lost through denitrification and volatilization varied from 4.7% to 34.7%. Zero water exchange system is highly efficient as nitrogen recovery is higher in shrimp and lower in discharge water. Lack of significant difference in metabolites between the SDs indicates the role of aeration and probiotics in sustaining SD16 cultures. 相似文献
12.
To understand the nutrient utilization efficiency and distribution in indoor fish culture system under treatment of probiotics, this study examined water quality and nitrogen budget in turbot Scophthalmus maximus culture system supplemented with four strains of lactic acid bacteria (LAB) isolated from fishery products. The results showed that the concentration of ammonia nitrogen (NH?‐N) and nitrite nitrogen (NO?‐N) in LAB treatments were all significantly lower ( p < 0.05) than in the control group. The nitrate nitrogen (NO?‐N) in LAB treatments showed no significant differences ( p > 0.05) compared with control group. The fish feed and water exchange accounted for 79.07% and 17.02% of total N input respectively. For N output, the drainage and residual diets in LAB treatment accounted for 24.50%–25.80% and 1.33%–1.60% respectively, and they were significantly lower than in the control group (27.60% and 2.20% respectively). Fish growth and lost N in LAB treatments accounted for 27.10%–30.50% and 11.00%–18.50% respectively, and they were both significantly higher ( p < 0.05) than in the control group (22.30% and 5.30% respectively). The results indicated that the indigenous LAB strains were capable of improving fish growth, and reducing NH?‐N and NO?‐N level (at concentration of 10 5 cfu/ml) by directly adding in S. maximus culture water. Moreover, specific strains of LAB may increase nitrogen loss by promoting denitrification process in culture system. 相似文献
13.
为建立缢蛏动态能量收支(dynamic energy budget,DEB)的数值模型,实验根据DEB理论,采用相应方法测定计算了建模必须的形状系数(δm)、阿伦纽斯温度(TA)、单位时间单位体积维持生命所需的能量[p M]、形成单位体积结构物质所需的能量[EG]和单位体积最大储存能量[EM]等基本参数。以水温和叶绿素浓度作为强制函数,针对围塘水质因子与春秋两季放养的缢蛏生长数据,利用STELLA 10.0软件构建了缢蛏的DEB模型。结果显示,缢蛏δm值为0.345 8,TA平均值为(5 448±960) K,[p M]=17.68 J/(cm~3·d),[EG]=4 050 J/cm~3,[EM]=1 840 J/cm~3;构建的DEB模型可以较好地模拟缢蛏软体部干重的生长,并且反映了不同时间的能量分配情况。春季放苗的缢蛏,在8月10日—9月20日,水温(29.8～32.2°C)为其主要生长限制因子;在9月30日—11月10日,食物为主要限制因子。秋季放苗的缢蛏,则在7月1日—9月20日表现出强烈的温度限制(30.5～32.2°C),而食物限制贯穿于整个模拟期间,在3月10日—5月20日限制最大。故秋季放苗的缢蛏更应在春季加大藻的培育,在夏季高温前达到上市规格。 相似文献
14.
Nitrogen (N) and phosphorus (P) budgets in a bioflocs technology (BFT) aquaculture system and a recirculation aquaculture system (RAS) during over-wintering of tilapia (GIFT Oreochromis niloticus)for 64 d were compared in the current study. Fish feed was the major input of N in both systems, specifically, 94±0 % and 82±4 % for the RAS and BFT aquaculture system, respectively. The rate of N recovery in the BFT aquaculture systems was estimated to be 48±5 % of input N, which was significantly different from that of the RAS (37±4 %). There was no significant difference between the RASs and BFT aquaculture systems in terms of P recovery rate. The regular backwashing of the drum filter and biological filter in RAS accounted for 41 ± 2 % of input N and 39 ± 2 % of input P. Approximately 54 % of unassimilated nitrogen N was removed by nitrification in the BFT aquaculture systems. The results from the present study suggest that nitrification may be the dominant pathway for ammonia removal in a BFT aquaculture system rather than by heterotrophic bacterial assimilation. 相似文献
15.
This study quantified the accumulation of nitrogen (N) in the water column, sediments, fish and seepage water during a production cycle of Colossoma macropomum. By combining estimates of the deposition rates of uneaten feed, faeces and dead phytoplankton with measurements of N accumulation in the sediment, the rate of decomposition of organic matter in the sediment was estimated. The first‐order rate constant for organic matter decomposition was 0.237±0.019 day ?1. Total N recovery during the first weeks of the experiment was about 65%. Later, the N recovery was close to 100%. The cumulative recovery at the end of the experiment was almost 100%, meaning that the N budget in the system studied can be fully explained without consideration of N volatilization, due to either denitrification or ammonia volatilization. In the beginning of the growth cycle, the major flux of N was sedimentation. Intensive microbial degradation process occurred about 3–4 weeks later, leading to a release of inorganic N and an approach towards a steady state as to the accumulation of organic N. Feed was irregularly applied during the experiment but fish growth was constant, showing that the fish utilized detrital or planktonic feed during periods of low feeding. Nitrogen accumulated in the pond during periods of excessive feeding and was utilized by the fish during periods of low feeding. This cycling should be further studied and may be an important pond management technique. 相似文献
16.
ABSTRACT: An experiment in which water was circulated between shrimp aquaculture ponds stocked with 10 000 or 20 000 PL-15 stage Penaeus monodon , and mangrove enclosures each planted with 476 Rhizophora mucronata per enclosure, was carried out at the Samut Songkhram Coastal Aquatic Research Station, Faculty of Fisheries, Kasetsart University, Thailand. Shrimp survival rate was significantly higher ( P < 0.001, Fisher's exact test) in ponds where 10 000 larvae was stocked and water was exchanged with the mangrove enclosure, compared with the control pond with no water exchange, over the 136 day experimental period. Phosphorus transport to the mangrove enclosure was estimated to be 0.41 kgP and 0.18 kgP over the experimental period and change in phosphorus content in mud was reduced there compared with the control pond. A load reduction effect to the environment was confirmed in this aquaculture system with mangrove enclosure compared with the phosphorus budget in the control pond, and 6.2 or 8.9 ha of mangrove area was estimated to be required by 1 ha shrimp ponds to fully process the phosphorus. 相似文献
17.
In this study, we investigated the effects of animal–plant protein ratio in extruded and expanded diets on nutrient digestibility, nitrogen and energy budgets of juvenile soft‐shelled turtle ( Pelodiscus sinensis). Four extruded and expanded feeds (diets 1–4) were formulated with different animal–plant protein ratios (diet 1, 1.50:1; diet 2, 2.95:1; diet 3, 4.92:1; diet 4, 7.29:1). The apparent digestibility coefficients (ADCs) of dry matter and crude lipid for diet 1 were significantly lower than those for diets 2–4. There was no significant difference in crude protein digestibility among diets 1–4. The ADC of carbohydrate was significantly increased with the increase in animal–plant protein. Although nitrogen intake rate, faecal nitrogen loss rate and excretory nitrogen loss rate of turtles fed diet 1 were significantly higher than those fed diets 2–4, nitrogen retention rate, net protein utilization and biological value of protein in these turtles were significantly lower than those fed diets 2–4. In addition, energy intake rate, excretory energy loss rate and heat production rate of turtles fed diet 1 were also significantly higher than those fed diets 2–4. Faecal energy loss was significantly reduced with the increase in the animal–plant protein ratio. The ADC of energy and assimilation efficiency of energy significantly increased with a higher animal–plant protein ratio. The growth efficiency of energy in the group fed diet 1 was significantly lower than those in the groups fed diets 2–4. Together, our results suggest that the optimum animal–plant protein ratio in extruded and expanded diets is around 3:1. 相似文献
18.
通过饲喂四个不同脂肪含量(3%、6%、9%、12%)的饵料,研究了饵料中脂肪含量对中华绒螯蟹生长和能量收支的影响,以期找出适合中华绒螯蟹生长的最佳饵料脂肪含量。结果表明,中华绒螯蟹呼吸能占摄食能的比例最高,生长能和粪能次之,代谢能最小;含脂肪9%的饵料生长能显著高于其他各组,而呼吸能显著降低。9%实验组有较高的特定生长率、相对增重率和饵料转化率。说明含有9%脂肪含量的饵料有助于中华绒螯蟹的生长。 相似文献
19.
控制养殖水体中溶解氧(DO)是高密度、集约化养殖模式的主要技术之一。概述了养殖水体中DO对养殖生物的影响，养殖水体中DO的日变化和季节变化以及水平和垂直分布规律，比较了各种氧收支及平衡研究模式和测定方法。展望了上述技术在工厂化养殖中的应用前景。 相似文献
20.
研究了盐度(0·5、5、10、15、20、25、30和35)对凡纳滨对虾Litopenaeus vannamei(平均初始湿重0·776~0.781g)存活、生长和能量收支的影响。实验周期45d。结果表明,(1)对虾特定生长率、摄食量、饲料转换效率和吸收效率均以20盐度最高,而存活率以35盐度最高;(2)在0.5盐度下,对虾特定生长率、摄食量和吸收效率均最低。 相似文献
|
