首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
崔立 《畜禽业》1999,(9):15-17
The yeast cell wall is recovered as a by-product during the production of soluble extracts from brewer's yeast(Saccharomyces cerevisiae).It is made up predominantry of glucan,mannan oligsaccharides,glucoprotein and chitin polymers.The glucan is a homopolimer of glucose linked through β—(1→3)and β—(1→6) D glycosidic bonds.The therapeutic effect of glucan has been primarily due to stimulation of reticuloendothelial system(RES).Studies have demonnstrated the effect of glucan in improving host resistancee by enhancing immunty to certain malingant tumors as well as to certain bacterial and viral infections.MOS's acts in the gut of animal capturing hostile gut-wall-attacking bacterla like E.Coli.Cell wall can be applied in all sorts feeds,but it is especially recommended for weaning piglets and aquaculture feeds.  相似文献   

2.
总论     
960754 大西洋西部,墨西哥湾和加勒比海北美鲳鲹和其它鲳鲹(鲹科)鱼类的养殖:现状与前景=Aquaculture of the Florida pom-pano and other jacks(Family Carangidae)inthe western Atlantic,Gulf of Mexico andcaribbean Basin:status and potential[著,英]/Wade O//Culture of High-Yalue Ma-rine Fishes in Asia and the United States.—  相似文献   

3.
鱼类热忍耐温度研究进展   总被引:25,自引:1,他引:25  
陈全震 《水产学报》2004,28(5):562-567
The paper is a review of the studies on the temperature of the thermal tolerance in fishes. It was described from four aspect: (1) The key parameters of temperature of thermal tolerance in fishes; (2) The influence factors of temperature of thermal tolerance in fishes; (3) The research methods of thermal effect of fishes; (4) The evaluation of effects of thermal pollution on fishes, especially, with the coastal power station will be‘built in China recent years, the effects of thermal discharge water on the marine fisheries resource wered iscussed.  相似文献   

4.
大西洋中部金枪鱼延绳钓渔场大眼金枪鱼的生物学特性   总被引:8,自引:3,他引:8  
宋利明 《水产学报》2004,28(2):216-220
Based on the biological data of bigeye tuna measured from the longlining ground of the Central Atlantic Ocean from Jun. 2001 to Oct. 2001, this paper analyzed the bigeye tuna‘s maturity stages of the gonad, feeding intensity, species composition of prey, sex ratio, fork length distribution, relationships between fork length and dressed weight, fork length and round weight, round weight and dressed weight by statistic and regression methods. The results indicate: ( 1 ) Maturity at Ⅳ-Ⅵ of the gonad are dominant with the highest percentage of Ⅴ (30.11% ). (2)The feeding intensity is mainly in the class 1 ,class 2 or class 3,totally 83.16%. (3)In the bigeye tuna‘s species composition of prey, the percentage of miscellaneous fish or cephalopod is relatively high, 38.05 % or 30.48 % respectively. Catch rate of bigeye tuna can be enhanced when cephalopod is used as the bait. (4) The male-female ratio is 2 : 1. This pattern might result from elevated mortality of adult females. (5) The fork length distribution is suitable for the normal. The dominant fork length is 1.13 - 1.49m, 64.16%, with the mean value of 1.32m. (6)The relationship between fork length and dressed weight. (7)The relationship between fork length and round weight. If the fork length is the same, the round weight converted in this paper‘s formula is a little lighter than the round weight converted in Parks‘s formula concluded at 1981 of the longline bigeye tuna catch. It might be caused by the different sampling areas or sampling time. (8)The relationship between round weight and dressed weight. The round weight conversion factor in this paper is a little higher than the ICCAT. It might be caused by the different processing methods. ICCAT is recommended to adapt this paper‘s conversion factor.  相似文献   

5.
草鱼加热过程中肌肉蛋白质的热变性   总被引:7,自引:0,他引:7  
吴燕燕 《水产学报》2005,29(1):133-136
The variations of muscle tissus, peroxidase and Ca2^2 -ATPase activities and Vp (pasteurization value) were investigated with the fresh samples of grass carp ( Ctenopharyngodon idellus ) heated at different temperatures, thus revealing the mechanism of denaturation of muscle protein by heating. The experimental results showed the great difference in muscle tissue structure before and after the samples heated. In the initial stage of heating the water loss accounted for 50% of the total. When the samples were separately heated at 75, 85, and 95℃, fk values (dehydration curve slope) were 5, 4.1 and 1.7, respectively, while Vp reaching 40 minutes were 22, 8 and 5 min, respectively. As to the time for deactivation of peroxidase in the heated samples at the various temperatures, it varied from 38, 10 and to less than 6 min, respectively and the deactivation rates of Ca^2 -ATPase in 1 min were 50%, 88% and 100%, respectively. Consequently, the higher temperature the sample was heated, the faster rate of thermocon ductivity, the lower rate of water loss, and the faster rate of peroxidase deactivation it was. Also, the Vp for the least requirement of pasteurization ( Vp≥40min) was obtained.  相似文献   

6.
甲胺磷、辛硫磷对坛紫菜叶状体的生理效应   总被引:8,自引:0,他引:8  
李钦 《水产学报》2004,28(2):221-224
In this paper, the effects of methmidophos and phoxim with different concentrations and schedule on soluble protein content and chlorophyl a (Chla) content in Porphyra haintanensis were studied under experimental and ecological conditions. The results showed as follows: (1) there were some time-effect and dose-effect relationships between the pollutants and Chla contents. The Chla content of most of groups decreased with the increasing of dose and prolonging of the exposure time. In the same concentration, the toxicities of phoxim to Chla content was stronger than that of methmidophos. (2) All concentration groups in this study didn‘t show the significant time-effect and dose-effect relationships between pollutants and the soluble protein. And there was no significant difference of the soluble protein content among various groups.  相似文献   

7.
甲壳动物渗透调节生理学研究进展   总被引:14,自引:3,他引:14  
潘鲁青 《水产学报》2005,29(1):109-114
Osmoregulation involves many aspects of physiological function in crustacean. Crustacean species exhibit almost all possible patterns of osmotic regulation and they are widely distributed in most of known biotopes. With the changes of liquid environment, the structure and function of the osmoregulation organs( such as gills, antennary glands) ,haemolymph osmotic pressure and ionic transport will turn to maintain the well-balanced metabolism, which are under the neuroendocrine regulation. The current research status of physiological mechanism of crustacean osmoregulation was reviewed in the following aspects. 1 ) Structure and function of gills and antennal glands(maxillary glands). The gills are very important organs and play a prominenet role in osmoregulatien; 2)Regulafien of ion transport in branchial epithelium. Ion transport enzymes (Na^ -K^ -ATPase, V-ATPase,HCO3^--ATPase and carbonicanhydrase)stimulated by bioamines and cAMP may participate in the ion transport of branchial epithelium in crustacean; 3 )Haemolymph composition and osmoregulation. Haemolymph concentration of ion and free amino acid accompanied by metabolites of blood can contribute to the most of haemolymph osmotic pressure; 4)Neuroendocrine control. Many neuropeptides may regulate the osraotic pressure of haemolymph and proteinsases activity of epithelial gill cells. Bioamines, cAMP and CaM have been proved to stimulate the uptake of Na^ and transport of Cl^-.  相似文献   

8.
IntroductionThe China Sea is divided into four sea regions(Fig.1) :the Bohai Sea(BS) ,the Yellow Sea(YS) ,theEast China Sea(ECS) and South China Sea(SCS) .The Bohai Sea,the Yellow Sea and the shelf of the EastChina Sea together form a broad epicontinental Sea.The average depth of Bohai Sea is18m and that of Yellow Sea is4 4m.Together,the Bohai Sea and Yel-low Sea form a gulf opening to the ECS.A shallow trough runs through the gulf and can be traced south tothe northern end o…  相似文献   

9.
对虾免疫机能研究概况   总被引:16,自引:0,他引:16  
陈国福 《水产学报》2004,28(2):209-215
Shrimp farming is an important source of revenue and employment in many developing countries.However, infectious diseases have adversely affected the profitability of shrimp industry. For this reason, disease prevention is a priority and shrimp immunology has become a crucial research area of this field. In this paper, the current importance and problems of shrimp-culture were described and the research advances in shrimp immunological defence mechanisms were summarized. The immunological tools are powerful and useful to evaluate the health state of the shrimp. The immunologies of shrimp mainly consist of cellular immunity and humoral immunity. In regard to cellular parameters, they are composed of haemocyte count (THC), differential haemocyte count (DHC) and reactive oxygen intermediates (ROIs). The immunity ceils exert their defence functions through phagocytizing, enveloping, etc, and the changes of THC and DHC are related to health state of shrimp. The ROIs generated during post phagocytic event which maybe an important marker to evaluate the immunological capability and phenoloxidase activity have been considered as a potential marker which is relevant to the health of the shrimp too. Concerning humoral parameters, prophenoloxidase (ProPO) and phenoloxidase,antimicrobial peptides and proteins, hemagglutinin and plasma proteins were described. The determining methods of immunity parameters were discussed. The response of shrimp to pathogens such as bacteria, virus, etc. and environmental factors such as DO, pH, etc, were also reviewed. It is well-known that the immune responses induced by immunizing crustacean or shrimp are mainly the non-specific immune responses. The potential of immunological parameters, including the changes of THC and DHC, the production of ROIs, phenoloxidase (PO) activity, antibacterial activity of plasma, and so on, to appraise the healthy state of shrimp were partly discussed. The future directions for the evaluation of the immunological capability of shrimp were proposed.  相似文献   

10.
水产养殖     
960851 挪威大西洋鲑和庸鲽养殖技术的最新改进=Recent improvements of farmingtechniques of Atlantic salmon(Salmo salar)and Atlantic halibut(Hippoglossus hip-poglossus)in Norway[著,英]/Holm J C//Culture of High-Value Marine Fishes in A-sia and the United States.—1994.—231~2391993年,挪威养殖大西洋鲑的产量为16万吨.直接批发价7亿美元,将平均生产成本降低到每千克2美元是可能的。Ⅱ龄鲑反季  相似文献   

11.
吴垠 《水产学报》2004,28(6):741-744
The effects of CO2 concentration on the growth and photosynthesis of Dicrateria zhang, jiangensis and Dunaliella sp, in 100 liter air lift photobioreactors were investigated. The results showed that biomass of both algae significantly increased in high CO2 concentration (above 700μL ? L^-1) compared to low CO2 concentration (350μL?L^-1) ,and the culture periods were shorter, However, no significant difference as observed in growth rate when the alga cultured in CO2 concentration of 700μL? L^-1 and 1000μL? L^-1, respectively. These for the maximum photosynthetic rate(Pm) and saturating irradiance level(Ik) of the two species remarkably raised with the elevated CO2 concentration, so was the initial slope(α)of Dunaliella sp.  相似文献   

12.
The mechanism of modulation of the Na/H antiport was studied in erythrocytes of the tilapia, Oreochromis mossambicus. Activation of the antiport was determined through measurements of variations of intracellular pH, using a pH-sensitive, intracellular fluorescent probe 2′, 7′-bis (carboxyethyl)-5 (6)-carboxyfluorescein (BCECF). Phorbol ester (5 μM), a stimulator of protein kinase C, activated the antiport resulting in an increase of intracellular pH; a maximum of 0.125 ± 0.027 pH units over basal level (mean ± SD; n = 4–6) was reached in 20 min. The effect was blocked by protein kinase C inhibitors staurosporine and H-7, and also by the antiport inhibitor 5-(ethyl-N-isopropyl) amiloride; this demonstrates that the stimulation of the antiport in tilapia erythrocytes can take place through a protein kinase C-mediated mechanism. Vasopressin, an important osmoregulator hormone in teleosts, was able to activate the Na/H antiport, in a manner similar to phorbol ester, but its effect was only partially sensitive to staurosporine inhibition. Considering that the physiological role of the Na/H exchanger in fish is known to be different from its role in mammalian cells, these results indicate that other signal transduction mechanisms can be involved in the modulation of intracellular pH by vasopressin. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

13.
江黄颡鱼卵细胞膜的结构特征   总被引:2,自引:0,他引:2  
刘利平 《水产学报》2005,29(3):420-423
Using conventional histochemical methods and scanning electron microscope, the egg surface of mature oocyte of Pelteobagrus vachelli was observed. The micropyle is funnel-like and consists of micropylar vestibule and micropylar canal. The opening of micropylar vestibule is about 11.35μm in diameter while entrance of the micropyle to the oocyte is only about 2.6 μm. There are plenty of micropores on the surface near the micropyle. Micropyle might act as an apparatus leading spermatozoa to penetrating an oocyte. Regular cord-like structures between basal membrane (the outermost layer of egg surface) and plasmic membrane (the inner layer of egg surface) are found. These cord-like structures, each about 16.75 to 18.50μm in length, 5μm in diameter, comprised small balls whose diameters vary from 2.18 to 2.5μm and are arranged cornpactly under the basal membrane. These kinds of structures are zona radiata and act as special eggshell. After activation of the oocytes, the cord-like structures would partially transform into mucoprotein. To our best knowledge, this paper is the fast report on stereo view of the zona radiata of teleost oocyte.  相似文献   

14.
IntroductionInherent to the practice of intensive aquaculture is the generation of wastes having immediate and verybroad effects on the aquatic environment.There is a growing consensus about the need to reduce waste pro-duction in aquaculture to minimize the negative impacts on the environment.Nitrogen(N) and phosphorus(P) wastes are major concerns for many aquaculture operations.In the past,formulation of diets in intensive aquaculture was often aimed at meeting requirements formaximum growt…  相似文献   

15.
赤点石斑鱼神经坏死病毒外壳蛋白全基因克隆与序列分析   总被引:5,自引:1,他引:5  
黄剑南 《水产学报》2005,29(3):429-432
  相似文献   

16.
大菱鲆胚胎的玻璃化冷冻保存   总被引:3,自引:0,他引:3  
田永胜 《水产学报》2005,29(2):275-280
Vitrification solutions were examined for their suitability of cryopreservation of turbot (Seophthulnms maximus) embryos. PMPI gave higher survival rate (75.68%) than other vitrification solutions and was considered to be suitable liar the cryopreservation of turbot embryos. The freezing point of the vitrification solutions consisted of PG and MeOH in the proportion of 3:2 was measured when the vitrification solutions were cryopreserved. It showed that the vitrification solutions with a cryoprotectant concentration of over 41% have no freezing point and the freezing points of vitrification solutions containing 33.33%-40% cryprotectants were between -32.4℃ and -65.4℃, The freezing point decreased with the increase of cryoprotectant concentration. The resistance of turbot embryos at different stages to the cryoprotectants was studied, It was found that the turbot embryos from 4-5 pairs somite to tail bud were more resistant to cryoprotectants and suitable to vitrify. A live embryo was obtained after cryopreservation in liquid nitrogen for 14h and was hatched out。  相似文献   

17.
水产食品特定腐败菌与货架期的预测和延长   总被引:25,自引:2,他引:25  
杨宪时 《水产学报》2004,28(1):106-111
Fresh fish and lightly preserved fish products are welcome by the global market, however, they are also among the most perishable food products. The research on specific spoilage organisms (SSO) reveals the spoilage process of aquatic product. This paper reviews the current knowledge (past ten years) on SSO of fresh fish and lightly preserved fish products with particular emphasis on characteristics of SSO and how to apply this concept to determine, predict and extend the shelf life of aquatic product. During storage, the microflora changes owing to different abilities of the microorganisms to tolerate the preservation conditions. SSO is defined as special microorganisms which can increase rapidly during preservation and has the ability to produce off- odours and off- flavours associated with spoilage, and spoilage metabolites. Identification of an SSO relies on comparison of the sensory and chemical characteristics of spoiled product with those of isolates from the spoilage microflora. Generally, the SSO of fresh fish may be a single species or genus, but the ones of lightly preserved fish products will be more complex. One exciting area for use of SSO aims to obtain quantitative knowledge about probable behavior of SSO and their function during the progression of spoilage. Thus mathematical models on the growth of SSO are established to evaluate the quality lost degree of product, which provide a sound information for the rational development of devices to monitor loss of products shelf life. Models for the growth of Pseudomonas spp, S. putrefaciens, P. phosphoreum have been established, and validated for shelf life prediction of seafood successfully. Another application field of SSO intends to develop the techniques to prolong the shelf life of food products by inhibiting SSO targetedly. Targeted inhibition of spoilage bacteria during preservation reduces their growth and results in a significant extension of shelf life in despite of the activity of non - spoilage organisms has not been influenced. Such techniques have been applied in perversion field of fresh fish and lightly preserved fish.  相似文献   

18.
^60Co-γ射线对成体长牡蛎生长的影响及致死效应   总被引:2,自引:0,他引:2  
刘晓 《水产学报》2005,29(3):424-428
Effects of ionizing irradiation of ^60Co-γ ray on mortality and growth of one year-old Pacific oysters ( Crassotrea gigas ) were studied. Irradiation was conducted at 4℃ and without sea water, and the survival, shell length, shell width, whole wet weight and condition index of irradiated oysters were measured. A biphasic dose response effect of 6^60Co-γ irradiation on Pacific oyster with high stimulatory response dose range to 100 Gy, and strong hormesis effects had been observed. Gamma ray induced mortality happened within 90 days after irradiation, and the relation between dosage ( D ) and mortality at 90 days could be described by the equation of M90 = 0.0041D^2- 0. 1816D (R^2= 0. 9958) with an LD50/90 of 135 Gy, indicating that the Pacific oyster has strong resistance to ^60Co-γ irradiation. Growth in shell length, shell width and whole wet weight of Pacific oyster were also enhanced by 60 Gy of ^60Co-γ ray. The condition index was also enhanced by ^60Co-γ irradiation in the dosage range from 40 to 100 Gy, with the maximum stimulatory response of 2.5 fold of control value at the 40 Gy dosage, suggesting that the accelerating effects of γ ray on growth of the Pacific oyster led to increase in dry meat. Results of this study showed that ionizing irradiation might be useful in the improvement of production traits in shellfish.  相似文献   

19.
1999年2月黄海声学调查鳀鱼种群群体结构评估   总被引:2,自引:2,他引:2  
IntroductionEstimation of the size structure of a fish population is often one of the primary objectives of an acoustic/trawl survey (Gunderson 1993;Honkalehto and Williamson 1996 ) .The size structure contains much informa-tion enabling a quick estimate of the fishable size of a stock in a regulated fishery or the recruitment status ofa stock.It is also a common practice to use the number at length of a population together with the age/lengthkey to produce the age structure of the fish popul…  相似文献   

20.
<正>The Journal of Resources and Ecology(JRE)is an international English language journal that was started in 2010.The journal is jointly sponsored by the Institute of Geographic Sciences andNatural Resources Research(IGSNRR).Chinese Academy of Sciences(CAS).the China Society of Natural Resources,and lhe Ecological Society of China.The Journal of Resources and Ecology's mission is to create a platform for the promotion of international academic exchange.The journal aims to provide a comprehensive representation of  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号