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911.
利用10个微卫星标记,对2代群体选育的建鲤(Cyprinus carpio var.Jian)和封闭水体的广西野生鲤鱼进行遗传多样性分析,共检测到53个等位基因,等位基因位点数在4~7个之间,平均等位基因数5.3个,片段长度在118~284 bp之间,有效等位基因在1.167 5~1.520 3,平均为1.360 2,广西野生鲤群体的有效等位基因数1.562,大于建鲤的1.388;位点观测杂合度在0.397~0.762之间,平均为0.562 6,期望杂合度0.301~0.629之间,平均0.463 3,广西野生鲤群体的期望杂合度0.581,大于建鲤的0.473;微卫星位点多态性信息含量(PIC)在0.289 7~0.685 0之间,平均多态信息含量0.438 8,为中度多态性,广西野生鲤群体多态信息含量0.685,大于建鲤的0.424,两个群体平均基因分化系数为0.106 9,广西本地野生鲤与建鲤的遗传距离为0.1463,相似性系数为0.828 4,表明广西野生鲤与建鲤之间存在明显的遗传异质性。  相似文献   
912.
观察了褐牙鲆(Paralichthys olivaceus)精子在室温和低温下的活力与寿命,并应用计算机辅助精子分析系统(CASA)对超低温冷冻前后褐牙鲆精子的运动特征进行了分析,结果表明:褐牙鲆精子在室温(25℃)下,可存活4 d,在低温(4℃)下可存活7 d;鲜精的活力为(87. 74±5. 47)%,解冻后,精子的最高活性为(84. 00±3. 67)%;激活0. 5 min时,冻精与鲜精的运动精子占总精子数的百分率(MOT)无显著性差异(P>0. 05),但精子平均曲线运动速度(VCL)、平均直线运动速度(VSL)、平均路径运动速度(VAP)和精子运动路线的曲折程度(LIN)都有显著性差异(P <0. 05);激活4min和10min时,冻精与鲜精的MOT、VCL、VSL、VAP和LIN间都有显著性差异(P <0. 05)。鲜精激活0. 5 min后,直线运动、曲线运动、左右摆动和不运动的精子数目占总精子数的百分比分别为(24. 49±3. 87)%、(48. 53±4. 55)%、(24. 72±2. 86)%和(2. 27±1. 22)%;冻精激活0. 5min后,直线运动、曲线运动、左右摆动和不运动的精子数目占总精子数的百分比分别为(18. 58±1. 33)%、(35. 67±3. 00)%、(35. 24±2. 67)%和(10. 51±1. 33)%。随着激活时间的延长,褐牙鲆鲜精和冻精的运动状态均发生了改变,直线运动和曲线运动的精子数目逐渐减少,而不运动和左右摆动的精子数目逐渐增加。  相似文献   
913.
A 60‐day feeding trial was conducted to examine the effects of different levels (0, 100, 200, 400 and 600 mg/kg) of antimicrobial peptides on growth, protease activity of foregut, the morphology of foregut villi and related genes mRNA expression level in the common carp (Cyprinus carpio). The results showed that the feed of antimicrobial peptides promote common carp growth, and the optimal dosage of antimicrobial peptides is 200–333 mg/kg in the common carp feed. The protease activity of 200 and 400 mg/kg groups were significantly higher than the control and other groups (p < 0.05). The foregut villus height with 100, 200 and 400 mg/kg antimicrobial peptide groups were significantly higher than control group (p < 0.05). The crypt depth of 200 and 400 mg/kg antimicrobial peptide groups were significantly lower than control group (p < 0.05). The ratio of villus height and crypt depth of 100, 200 and 400 mg/kg antimicrobial peptide groups were significantly higher than control group (p < 0.05). The ratio with 600 mg/kg group was significantly lower than the control group (p < 0.05). The IGF‐I gene expression level of 200 mg/kg and 400 mg/kg groups were significantly higher than the control group and 600 mg/kg group (p < 0.05). The IL‐1β gene expression level of 100 mg/kg and 200 mg/kg groups were significantly higher than the control group (p < 0.05). These results indicated up‐regulation of growth and immune related genes in antimicrobial peptides fed common carp. Correlation analysis showed that IGF‐I mRNA and IL‐1β mRNA were positively correlated with SGR. IL‐1β mRNA and FCR were significantly negative correlated. It indicated that growth and immune gene common regulated the growth of the carp under antimicrobial peptides intervention. In conclusion, antimicrobial peptides can improve growth and related genes mRNA expression in the common carp. Further studies using molecular biological technique or immunologic methods are required to conclude that antimicrobial peptides are beneficial in common carp.  相似文献   
914.
Maize gluten (a byproduct from the starch industry) was used at four different levels (5, 10, 15 and 20% w/w) replacing the fish meal, a component of supplementary diet, under a semi-intensive culture system. The impact of different diets on the physico-chemical parameters of water, growth and flesh quality of catla, Catla catla; rohu, Labeo rohita; and mrigal, Cirrhina mrigala was studied. Growth in terms of body weight gain was highest when fed a diet having 5% maize gluten (replacing fish meal at 25% level) for all the fish species. However, incorporation of maize gluten at higher levels led to decline in growth, since maize gluten is deficient in essential amino acids like methionine, lysine and threonine, etc. The flesh quality in terms of total protein, total lipid, total sugar, moisture and total ash was also determined at the termination of the experiment to see whether there was any significant variation with the incorporation of maize gluten or not.  相似文献   
915.
鲁西黄牛耳缘组织成纤维细胞的体外培养   总被引:1,自引:0,他引:1  
实验以鲁西黄牛耳缘组织为研究材料,采用组织块贴壁培养法对其进行了成纤维细胞的体外培养。通过细胞的传代培养、形态学和动力学观察与分析,结果表明,所建立的鲁西黄牛耳缘组织成纤维细胞系具有典型的成纤维细胞形态,胞体均为梭形和不规则三角形,且细胞丰满;细胞核形态为卵圆形,并位于胞质中央,核仁清晰。在细胞生长于繁殖过程中亦经历了潜伏期、指数增生、停滞期和衰退死亡期等4个时期。细胞群体倍增时期为72h。实验结果表明,已成功地培养了鲁西黄牛耳缘组织成纤维细胞。  相似文献   
916.
The lion's paw scallop, Nodipecten subnodosus (Sowerby) has considerable aquacultural potential due to its fast growth and large adductor muscle. Prior investigations throughout northwestern Mexico's littoral have reported highly variable growth rates; furthermore, no studies are available of the environment on growth and gametogenesis in this species under culture conditions. This investigation assesses the effect of food availability and temperature on the growth and gametogenesis of N. subnodosus in a suspended culture system at Guerrero Negro lagoon, Mexico. After 1 year of cultivation, N. subnodosus reached 69.13 mm in shell height (SH) (0.196 mm day?1, 14 months old). Two significant growth spurts were observed: over the two first months of culture (August and September 2001, mean growth rate 0.4 mm day?1) and in September 2002 (0.3 mm day?1), both related to high temperatures and chlorophyll a concentrations. The onset of gametogenesis occurred in April 2002, with an increase in temperature (10‐month‐old scallops, 54.5 mm SH). The first spawning occurred in October and November (86.2 and 93 mm SH), with peak temperatures. These results, together with the analysis of previous reports, indicate that N. subnodosus has a higher preference for temperate areas; therefore, the Guerrero Negro lagoon appears to be a suitable site to culture this species.  相似文献   
917.
The present study aimed to determine whether protection is conferred by immunization of grouper, Epinephelus coioides, against a protozoan parasite, Cryptocaryon irritans. The immunization of E. coioides was carried out by a low level exposure of fish to live C. irritans theronts from predetermined number of tomonts and by an intraperitoneal injection of a vaccine consisting of formalin-killed C. irritans theronts.

Mucus titers detected by ELISA were significantly higher in fingerling and adult grouper subjected to the low level of exposure to C. irritans theronts at 3-week post-exposure compared to fish that had no previous exposure. In addition, significantly smaller tomonts were produced from adult grouper after three successive exposures than the tomonts produced after a single exposure to the parasite.

In the vaccine-immunization experiment, no mortality was monitored in fish that received high dose vaccine (100 μg/fish), while 40% cumulative mortality and 100% cumulative mortality were recorded in low dose group (10 μg/fish) and control group (PBS-injected), respectively. In the succeeding replicate, the vaccine-immunized group (high dose) had 37.5% cumulative mortality and 100% cumulative mortality for the control. In addition, a total of 1830 tomonts were collected at 5-day post-challenge from the control group while none from the vaccine-immunized group. Significantly fewer trophonts and tomonts were enumerated at 5-day and 7-day post-challenge, respectively, in the vaccine-immunized group than the control.

Results suggest that a protective immunity has been conferred on the immunized grouper as indicated by high antibody titers in the mucus of C. irritans-exposed fish and higher survival and fewer parasites in vaccine-immunized fish than the control groups. The conferred immunity played a major role in preventing or limiting the adhesion, invasion, and development of C. irritans theronts on the skin of the immunized grouper.  相似文献   

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920.
文章针对深水网箱养殖过程中岸电供应不便而给网衣的水下清洗带来极大困难的问题,研制了歧管式高压射流水下洗网机,克服了高压仓式洗网机水头损失大的缺点。通过水力学计算得到歧管式高压射流水下洗网机射流压力P=5.57MPa、喷嘴孔径d=2.6mm、射流速度v=104.1m·s。和射流功率P=12.3kW、射流反冲力F=234.96N。水下洗网机的海上清洗试验表明,在工作泵满足工作压力和设计流量条件下,歧管式高压水射流水下洗网机的综合性能达到了设计要求。  相似文献   
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