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1.
To investigate the stimulating effects of immunostimulants on the autogenous immunocompetence of crabs and the possible mechanisms involved, the immunostimulating effects of β-1,3-glucan, lipopolysaccharide (LPS), inactivated Vibrio harveyi and Vibrio anguillarum on phenoloxidase (PO) and hemocytes of Charybdis japonica were investigated in this study. It was found that the yields and the enzymatic activities of purified PO in C. japonica increased significantly after the crabs were treated with immunostimulants, while the unit enzymatic activities remained almost the same. After treatment with β-1,3-glucan and LPS, the amount of rough endoplasmic reticulum (RER) and the number of mitochondria in both semigranular cells and granular cells increased greatly, and the number of cytoplasmic granules decreased but with enlarged volume. However, the corresponding characteristics of hyaline cells remained almost the same. On the other hand, the number of granules in semigranular cells decreased greatly, and the number of mitochondria of hyaline cells increased greatly, after treatment with inactivated vibrios. It may be concluded that the effect of polysaccharide immunostimulants on the innate immune system of C. japonica is different from that of inactivated vibrio immunostimulants. The immunity-enhancing mechanism of polysaccharides in crab autogenous immunocompetence is probably accomplished by the increased yields of PO and total PO activities, while that of inactivated vibrios is probably accomplished by the partially increased yields of PO and total PO activities as well as the significantly improved phagocytotic abilities of semigranular cells and hyaline cells.  相似文献   

2.
Monthly investigations were mae on the population of Chinese freshwater crab,Sinopotamon yangtsekiense Bott, 1967 from April, 1984 to March, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs' major development occurred from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June–October. Females bearing eggs were taken from June–August, and crabs with young were found from July–October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-born crabs become mature after 1–2 years. The sex ratio was approximately 1∶1 in the overall population. However, the larger crabs are predominantly male. The age distribution ofS. yangtsekinese was estimated from size frequency histograms. There were more adult crabs (over 70%) from June to October and more immature crabs (over 50%) from November to May.  相似文献   

3.
Immunostimulants may improve disease resistance of aquaculture animals by promoting the nonspecific immunity response of the organisms. Five types of saccharides, including chitosan, yeast polysaccharide, burdock oligosaccharide, seaweed polysaccharide and lentinus edodes polysaccharide, were screened for potential use as immunostimulants by using spectrophotometry. The saccharides were injected into Apostichopus japonicus, a sea cucumber, and the lysozyme and superoxide dismutase (SOD) activities of the coelomic fluid and epidermal slime were monitored in six consecutive days. The results show that the lysozyme activity of the animal’s coelomic fluid was significantly stimulated on day 2, day 4 and day 6 after the injection of the saccharides (P<0.05). The effects of chitosan and yeast polysaccharide were the most notable. The lysozyme activity of the epidermal slime was significantly increased by chitosana, yeast polysaccharide, seaweed polysaccharide, and burdock oligosaccharide on day 1 and day 2 after the injection (P<0.05). The SOD activity of the coelomic fluid was significantly promoted by the saccharides on day 2 and day 4 post-injection (P<0.05), while the SOD activity of the epidermal slime increased on day 2. These findings indicate that chitosan and yeast polysaccharide are the most effective immunostimulants and potential healthy anti-disease feedstuff for A. japonicus. Supported by the National Key Technology Research and Development Program (863 Program, No. 2006BAD09A06) and the Special Fund of Chinese Central Government for Basic Scientific Research Operations in Commonweal Research Institutes (No. 02-2007B03)  相似文献   

4.
研究了海水网箱养殖海域弧菌数量变化、种类组成及其相关因素,探讨弧菌数量的变化与鱼病的关系。结果表明:网箱内水体弧菌数量为390~230 mL-1,平均为20.6×102mL-1,网箱外水体为130~1450 mL-1,平均为530 mL-1,非养殖对照海区为10~390 mL-1,平均为190 mL-1。养殖海区弧菌数量呈现明显的季节性变化,尤其是网箱水体,对照海区只在9月数量较高,其他时间变化不大。平均数量网箱内大于网箱外,网箱外大于对照海区。水体中出现的弧菌种类有河流弧菌Vibrio fluvialis,创伤弧菌Vibrio vulnifgicus,霍乱弧菌Vibrio cholerae,副溶血弧菌Vibrio parahaemolyticus,溶藻弧菌Vibrio alginolyticus,美人鱼弧菌Vibrio damsela,拟态弧菌Vibriomimicus和好利斯弧菌Vibrio hollisae,美人鱼弧菌、溶藻弧菌和霍乱弧菌占有较大优势。弧种数量与海水温度、盐度及营养盐有相关性,但其相关性因不同种和不同点而不同。检测期间,网箱养殖鱼类无明显流行病发生,但弧菌的高峰期明显与报道的鱼病高峰期相吻合。  相似文献   

5.
Polychaete Neanthes japonica is a species geographically specific in China and Japan with important scientific implication and commercial value. In this study, the relations of body weight, salinity and temperature to oxygen consumption and ammonia excretion of N. japonica were determined. Three different groups in body weight (large: 2.34±0.36 g, middle: 1.50±0.21 g and small: 0.62±0.12 g) were set for all experiments. Results show that the body weight is negatively related to the rates of oxygen consumption and ammonia excretion; and the relationship is significant. The oxygen consumption and ammonia excretion at 24°C decreased at salinity from 5 to 30 and increased above 30, indicating that both lower and higher salinity are adverse and certain degree of salinity stress is necessary for enhancing the energy demand. At salinity 30, rising temperature from 18°C to 30°C, the oxygen consumption increased before 27°C and then decreased. However, the relation of ammonia excretion and temperature seems more complex. Two-way ANOVA shows that salinity, temperature and body weight all have a significant effect on the oxygen consumption and ammonia excretion of the worm. Moreover, interaction between salinity/temperature and body weight is also significant. O:N (oxygen/nitrogen) ratio varies greatly in this case from 5.97 to 463.22, indicating that N. japonica can regulate the type of metabolic substrate against environment changes. Supported by the National Natural Science Foundation of China (No. 30490233) and the Three-Gorge Project and the Estuarine Environment (No. SX2004-018) from the Three Gorges Project Construction Committee  相似文献   

6.
The pathological changes of hemocytes in the haemolymph and hepatopancreas were examined in experimentally and naturally WSSV (white spot syndrome virus) infected Fenneropenaeus chinensis. The results showed that the pathological manifestations of hemocytes were similar among moribund shrimps infected via injection, feeding and by nature. Firstly, the total hemocyte counts (THCs) in WSSV-infected shrimp were significantly lower than those in healthy shrimp. Secondly, necrotic, broken and disintegrated cells were often observed, and a typical hematolysis was present in the haemolymph smear of WSSV-infected shrimp. Thirdly, necrosis and typical apoptosis of hemocytes were detected with TEM in the peripheral haemolymph of WSSV-infected shrimp. Hyalinocytes and semi-granulocytes with masses of WSSVs in their nuclei often appeared, whereas no granular hemocytes with WSSV were found in the hepatopancreas of moribund infected shrimps. All our results supported that hemocytes were the main target cells of WSSV, and hyalinocytes and semigranular hemocytes seemed to be more favorable for WSSV infection in F. chinensis.  相似文献   

7.
Vibrio harveyi cells (dose—<103 cells mL−1) and extracellular products (ECP; >25 μmg mL−1 of total protein concentration) destroyed haematopoietic cultures of Nephrops norvegicus within 24 h of exposure. Cytopathic effects (CPE) started after 4h of exposure to the bacterial cells, with some granularity in the cytoplasm, mostly in cells in the outer periphery of the explant growth. At the end of the infection, a considerable number of nuclei remained attached to the substrate, apparently unaffected. Following exposure to ECP, initial deterioration was observed at 2 h with the presence of granularity in the cytoplasm of<20% cells, and few cells displayed small vacuoles around the nuclei. Parallel results were obtained using whole animal experiments, with V. harveyi cells being lethal to nephrops within 24 h.  相似文献   

8.
研究波吉卵囊藻及藻―菌体系对创伤弧菌(Vibrio vulnificus)、副溶血弧菌(Vibrio parahaemolyticus)和溶藻弧菌(Vibrio alginolyticus)生长的影响,结果显示:无菌波吉卵囊藻对创伤弧菌、副溶血弧菌的生长均有显著促进作用(P<0.05),对溶藻弧菌的生长无显著影响(P>0.05);波吉卵囊藻―沼泽红假单胞菌体系对溶藻弧菌有明显抑制作用(P<0.05);无菌波吉卵囊藻―枯草芽孢杆菌体系对溶藻弧菌的生长有显著促进作用(P<0.05),对创伤弧菌、副溶血弧菌的生长无显著影响(P>0.05);带菌波吉卵囊藻对三株弧菌均有明显抑制作用(P<0.05);带菌波吉卵囊藻共栖细菌对三株弧菌均无明显抑制作用(P>0.05);在无菌波吉卵囊藻中回加带菌藻共栖细菌,分析实验10～18d的数据发现的数据发现藻―菌体系对创伤弧菌、副溶血弧菌的生长有显著影响(P<0.05),藻―菌体系逐渐恢复对三株弧菌的抑制作用。  相似文献   

9.
We established a line (screened) of Portunus trituberculatus by selectively breeding individuals that survived from challenge with Vibrio alginolyticus, and compared the response of screened and unscreened (control) P. trituberculatus challenged with V. alginolyticus. We measured superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase, and peroxidase activity and the content of hemocyanin in the plasma and phenoloxidase activity in serum. The cumulative survival rate after 24-h challenge with V. alginolyticus was significantly higher in the screened crabs than in the unscreened crabs (P<0.05). T-SOD and PO activity were significantly lower in the screened stock than in the unscreened stock (P<0.05). POD, CAT, and ACP activity and hemocyanin content were significantly higher in the screened stock than in the unscreened stock. Our results suggest that the screened stock was more resistant to infection. Furthermore, the indices we measured may be used to evaluate the health state of P. trituberculatus.  相似文献   

10.
There are rising concerns about the hazardous effects of heavy metals on the environment. In this study, comet assay and DNA alkaline unwinding assay were conducted on the tissues (gills, hepatopancreas, and hemocytes) of Charybdis japonica in order to illustrate genotoxicity of three heavy metal ions (Cu2+, Pb2+, and Cd2+) on the marine crabs C. japonica. The crabs were exposed to Cu2+ (10, 50, and 100 ?g.L?1), Pb2+ (50, 250, and 500 ?g L?1) and Cd2+ (5, 25, and 50 ?g L?1), and the tissues were sampled at days 0.5, 1, 3, 6, 9, and 15. DNA alkaline unwinding assay was used for testing the DNA single strand break in gills and hepatopancreas and comet assay was employed for testing the DNA damage in hemocytes. The results showed that the DNA damage (F-value) of gills in the crabs exposed to the three heavy metals was decreased gradually during the exposure periods and there was a dose-time response relationship in certain time, suggesting that the levels of DNA single strand break in all the experimental groups increased significantly compared to the controls. Changes of F-value in hepatopancreas of the crabs exposed to the three heavy metals were similar to those in gills except that the peak values were found in the 500 ?g L?1 Pb2+ treatment group at day 3 and the 50 ?g L?1 Cd2+ treatment group at day 9. The ranks of DNA damage in gills and hepatopancreas induced by the three heavy metal ions (50 ?g L?1, day 15) were Cd2+ >Pb2+ >Cu2+ and Pb2+ >Cu2+ >Cd2+. The levels of DNA damage in gills were higher than those in hepatopancreas in the same experimental group. It can be concluded that indices of DNA damage can be used as the potential biomarkers of heavy metal pollution in marine environment.  相似文献   

11.
Sea cucumbers, Apostichopus japonicus Selenka, were fed diets containing non-immunostimulant (basal diet), 0.2% β-glucan and 0.02% glycyrrhizin in a recirculatory water system for 45 days, and subsequently challenged with Vibrio splendidus by injection at 1.0×108 cfu / sea cucumber for 15 days. Phagocytic capacity (PC), intracellular superoxide anion production (ISAP), lysozyme (LSZ) activity and superoxide dismutase (SOD) activity in the coelomic fluid were analyzed on the 0th, 5th, 10th and 15th days after injection. Results showed that after the 45-day feeding period, PC, ISAP, LSZ activity and SOD activity in sea cucumbers fed with dietary β-glucan or glycyrrhizin were significantly higher than in those fed with the basal diet. On the 5th day after infection, all the immune parameters examined in the sea cucumbers injected with V. splendidus decreased in value significantly. On the 15th day, PC, ISAP and LSZ activity returned to levels similar to those on the 0th day. For the sea cucumbers injected with saline, there were no significant differences in all the immune parameters examined and in the cumulative morbidity during the 15-day challenging trial. After injecting with V. splendidus, the cumulative morbidity of sea cucumbers fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin when challenged with V. splendidus challenged sea cucumber fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin. There was no significant difference in cumulative morbidity between the dietary β-glucan and glycyrrhizin treatments over time.  相似文献   

12.
Prepared in this experiment were six groups of diets, i.e. VC0, VC1, VC2, VC3, VC4 and VC5 with the contents of vitamin C (VCmg(100 g)−1 diet) of 0, 100, 200, 400, 800, and 1200 respectively. It was found that vitamin C increased the concentrations of immunoglobulin-like (IgG-like, IgA-like and IgM-like) substances in the serum of Penaeus chinensis after a feeding period of 3 weeks. The differences among groups were significant (P<0.01), but there was no difference in the contents of complement3-like and complement4-like substances in the serum (P>0.05). Phenoloxidase (PO) activity in the serum of VC3 group shrimps was higher than that of VC0 and other groups, but no significant difference was observed between VC0 group and other groups. Furthermore, bactericidal activity of the serum to Vibrio parahaemolyticus in shrimps fed with the VC1 diet was higher than that in the other groups (P<0.01), while no difference was demonstrated among all groups for the bactericidal activity to Vibrio alginolyticus (P>0.05). It is, therefore, suggested that vitamin C (100–400 mg(100 g)−1 diets) could be used as an immunostimulant of P. chinensis.  相似文献   

13.
Growth and energy budget of the polychaete, Neanthes japonica, at various temperatures (17, 20, 23, 26 and 29°) were investigated in this study. The growth, as indicated by final dry weight and specific growth rate (SGR), increased with increasing temperature, with the maximum level at 26°C, and then decreased significantly at 29°C. A similar trend was observed in feeding rate, food conversion efficiency (FCE) and apparent digestive rate (ADR). However, no significant differences were detected in ADR among all the temperature treatments. In the pattern of energy allocation, faeces energy was only a small component of energy budget and had little influence on the proportion of food energy allocated to growth. The metabolic energy accounted for a large portion of energy intake for each temperature treatment. The nitrogen excretion was appreciable with changing temperature. The two expenditure terms (respiration energy and excretion energy) in energy budget were the major factors influencing the proportion of food energy allocated to growth. These results revealed that temperature affected the growth of N. japonica mainly by influencing feeding rate and FCE. In addition, regression equations describing the relationship between feeding rate, faecal production, SGR, FCE and temperature were obtained. The optimum temperatures for feeding rate, FCE and SGR were estimated at 25.01°C, 24.24°C and 24.73°C, respectively, from the regression equations.  相似文献   

14.
Extracellular products (ECP) produced byVibrio anguillarum strain M3 originally isolated from diseased flounder (Paralichthys olivaceus) were prepared. ECP of M3 showed gelatinase, casinase, amylase and haemolytic activity on agarose plates. High protease activity against azocasin was detected. Bacterium M2 showed highest growth and protease activity at 25°C. The protease present in ECP showed maximal activity at pH 8 and 55°C; was completely inactivated by application of 80°C heat for 30 min; was completely inhibited by EDTA and HgCl2, and was partially inhibited by PMSF, SDS, MnCl2 and iodoacetic acid; but not inhibited by CaCl2 and MgCl2. The ECP was toxic to flounder fish at LD50 values of 3.1 μg protein/g body weight. The addition of HgCl2 and application of heat at 50°C decreased the lethal toxicity of ECP. When heated at 100°C, ECP lethality to flounder was completely inhibited. After intramuscular injection of ECP into flounder, it showed evident histopathological changes including necrosis of muscle, extensive deposition of haemosiderin in the spleen, dilated blood vessels congested with numerious lymphocytes in the liver. These results showed that ECP protease was a lethal factor produced by the bacteriumV. anguillarum M3. Contribution No. 4213 from the Institute of Oceanology, Chinese Academy of Sciences. Funded by projects under the Major State Basic Research Development Program, Grant G1999012003.  相似文献   

15.
Accordion-shaped traps are widely used in China to catch the Asian paddle crab Charybdis japonica but traps of conventional design often catch juvenile crabs. A new type of accordion-shaped trap with an escape vent (L×W=4.3 cm×3.0 cm) was designed and a comparative study between the newly designed and conventional traps was performed in the artificial reef area of Zhuwang, Laizhou Bay, China from June to August 2012. The mean catch per unit effort (CPUE) of undersized crabs was significantly lower in the vented traps than in the conventional traps (paired t -test, n=30, P<0.001), while the CPUE of marketable crabs was significantly higher in the vented traps (paired t-test, n=30, P<0.001). The mean size of crabs (carapace length) caught in the vented traps was significantly larger than in conventional traps (paired t-test, n=29, P<0.001). The ratio of undersized crabs was 35.05±2.57% in conventional traps and 12.53±0.69% in vented traps (significantly lower, paired t-test, n=29, P<0.001). Therefore, a 4.3 cm×3.0 cm escape vent was considered appropriate for C. japonica fishing in the artificial reef area. This finding will assist the development of more sustainable and efficient crab fishing methods using accordion-shaped traps.  相似文献   

16.
For the investigation of anti-infection immune response of Pseudosciaena crocea, 160 healthy fish samples were categorized into infected and control groups. Each individual fish in the infected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension of Vibrio alginolyticus in density of 2×107 CFU/ml, while each individual in the control group was injected i.p. with 0.2 ml sterile saline solution (0.85%). It was observed that the artificial injection of V. alginolyticus significantly increased the number of erythrocytes, leucocytes, lymphocytes in peripheral blood as well as peripheral serum antibacterial activity and antibody titer of large yellow croaker, and significantly reduced the number of peripheral blood granulocytes as compared with those in the control group. No significant difference in acid phosphytase and superoxide dismutase activity of serum was detected between the two groups. It is suggested that non-specific immune factors including leucocytes and anti-bacteria substance in peripheral blood played important role at the initial stage of infection, and specific immune factors such as antibody then played important role in response to anti-infection at the latter stage. Supported by the National High Technology Research and Development Program of China (863 program, No. 2007AA09Z115) and Technology Program of Xiamen (No. 3502Z73019)  相似文献   

17.
为了解九孔鲍养殖环境中细菌生理菌群的生态作用,对分离自养殖水体的33株菌株的产酶能力和种类进行了研究。结果表明,具有分泌胞外蛋白酶、脂肪酶和纤维素酶能力的菌株分别为39.4%、57.6%和30.3%;在这33株菌中,产至少一种胞外酶的菌株比例高达63.6%。API鉴定结果表明,在有能力分泌胞外蛋白酶、脂肪酶和纤维素酶的菌株中,弧菌菌群所占的比例分别为46%、42%和40%,而其中河流弧菌又占各弧菌菌群比例的83.3%、62.5%和100%。充分阐明弧菌,尤其是河流弧菌为优势菌,在鲍鱼养殖微生物态中起的重要作用。  相似文献   

18.
We studied the effects of mercury (Hg2+) on antioxidant and digestive enzyme activities in terms of LC50 value and on hepatopancreas histostructures of juvenile Chinese mitten crabs Eriocheir sinensis in 40-day exposure to various concentrations of Hg2+ (0, 0.01, 0.05, 0.10, 0.20, and 0.30 mg/L). The results show that the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) significantly increased in the concentrations of 0.01 and 0.05 mg/L, while that of enzyme decreased in 0.10, 0.20 and 0.30 mg/L treatments. Meanwhile, Hg2+ disrupted the histostructures of the hepatopancreas, causing decreases in activities of pepsin, tryptase, amylase, and cellulose, which are synthesized in the hepatopancreas. Moreover, as the Hg2+ concentration increased, the survival rate of the crabs decreased, worst at 56.57% in 0.30 mg/L. Therefore, although crabs are able to tolerate low levels of mercury pollution, high levels lead to cellular injury and tissue damage in hepatopancreas, which then loses some of its vital physiological functions such as absorption, storage, and secretion.  相似文献   

19.
The ultrastructure of hemocytes ofPenaeus vannamei was examined by transmission electron microscope. Three types of hemocytes were identified: hyaline cell, small-granule cell and large-granule cell. Hyaline cells are the smallest of the hemocytes, lack electron-dense granules, have average size of 11.11 μm (SE±0.50,n=10)×6.96μm (SE±0.55,n=10), comprise 25.8% (SE±2.87,n=4×10) of the hemocytes; small granule cells are the most abundant type of hemocytes, comprise 58.1% (SE±3.40,n=4×10) of the hemocytes, contain small electron—dense granules, have average size of 10.78 μm (SE±0.60,n=10)×8.63 μm (SE±0.44,n=10); and large-granule cells comprise 16.1% (SE±2.55,n=4×10) of the hemocytes, are filled with large electron dense granules, have average size of 12.51 μm (SE±0.63,n=10)×8.99μm (SE±0.71,n=10). This research was supported by the National Climbing Project B, PDB6-6-3. Contribution No. 3448 from the Institute of Oceanology, Chinese Academy of Sciences.  相似文献   

20.
The disease resistance and humoral immunomodulatory effects of vitamin C administered orally to grouper,Epinephelus awoara maintained on a frozen fish diet supplemented with vitamin C at 500, 1000, 1500 and 2000 mg/kg were investigated. After 20 weeks, the growth rates of the groups with high level of vitamin C apparently increased. The untreated fish had symptoms of vitamin C deficiency. The endogenous liver tissue vitamin C levels were found to reflect well the dietary treatments. After intraperitoneal injection or bath challenge with a virulent strain ofVibrio vulnificus, fish fed with high level vitamin C showed significantly higher survival rate compared with the normal control group. Vaccination with formalin inactivatedV. vulnificus significantly enhanced the specific antibody production in fish treated with vitamin C, and completely protected from strong bacterial challenge the groups fed on fish with vitamin C 1500 and 2000 mg/kg diet. Project 39500113 supported by NSFC and also by Guangdong Science Research Foundation (Grant No. 950711).  相似文献   

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