Low-density silver carp Hypophthalmichthys molitrix (Valenciennes) polyculture does not prevent cyanobacterial off-flavours in channel catfish Ictalurus punctatus (Rafinesque)     

Craig S Tucker 《Aquaculture Research》2006,37(3):209-214

Silver carp Hypophthalmichthys molitrix (Valenciennes) were co‐cultured with channel catfish Ictalurus punctatus (Rafinesque) in 0.4 ha earthen ponds to determine the impacts of carp grazing on pond phytoplankton communities and cyanobacterial off‐flavours in catfish. Carp were stocked at densities of 0, 75, or 250 fish ha^?1 in seven replicate ponds per treatment. The mean chlorophyll a concentrations (a measure of phytoplankton standing crop) steadily increased in all treatments from about 100 μg L^?1 in April to more than 400 μg L^?1 by mid‐October. Silver carp had no affect (P>0.1) on chlorophyll a concentrations across all sampling dates (April though October) or for sampling dates late in the growing season (August–October) when the prevalence of cyanobacterial off‐flavours among catfish populations is usually greatest. Silver carp did not eliminate odour‐producing cyanobacteria from pond phytoplankton communities: on sampling dates in September and October, three to six ponds in all treatments contained populations of the odour‐producing cyanobacteria Oscillatoria perornata, Anabaena spp., or both. Failure of silver carp to eliminate odour‐producing cyanobacteria resulted in a relatively high incidence in all treatments of ponds with off‐flavoured catfish. On sampling dates in September and October, catfish in three to five ponds in each treatment were tainted with either musty (2‐methylisoborneol) or earthy (geosmin) off‐flavours. The presence of silver carp had no obvious effect on off‐flavour intensity: on each sampling date, at least three ponds in each treatment contained catfish described as distinctly to extremely off‐flavored. Apparently, hypertrophic conditions in catfish ponds overwhelm the effect of silver carp grazing at the low carp densities used in this study.  相似文献   

棉酚对鲤鱼急性中毒的研究   总被引：4，自引：0，他引：4  

卢彤岩  富惠光等 《水产学杂志》1994,7(1):45-48

鲤鱼（体重约16克）腹腔注射乙酸棉酚0，7．3，54，100，200，400mg/kg体重，经四天（96小时）后，死亡率分别是0，0，20％，70％，90％，100％。96小时半数致死剂量是63．6mg/kg体重。注射剂量高于54mg/kg体重时，发生腹腔红肿、体壁溃烂，甚至死亡。实验结果说明虽然棉籽水平的棉酚不引起鲤鱼的任何可见的中毒症状，但是腹腔注射大剂量棉酚可引起与哺乳类相似的中毒症状。  相似文献   

Binding and bioactivity of insulin in primary cultures of carp (Cyprinus carpio) hepatocytes     

Helmut Segner  Ralf Böhm  Werner Kloas 《Fish physiology and biochemistry》1993,11(1-6):411-420

Isolated carp hepatocytes cultured in serum-free, chemically defined medium were used to investigate within the same cell preparation characteristics of the binding of insulin as well as effects of insulin on cellular metabolism. The binding of human [¹²⁵I]-insulin to carp hepatocytes was studied in kinetic, saturation and displacement experiments. A dependency of insulin binding on the collagenase used for cell isolation was demonstrated. Insulin binding decreased during the first 12h of culture but remained constant during the following 12h. The kinetic experiments revealed that [¹²⁵I]-insulin binding reached a steady state within 20–30 min of incubation. The mathematical analysis of the saturation experiments demonstrated the existence of two populations of binding sites, one with high affinity (K_d1 = 5.5 pM) and low capacity (B_max1 = 0.14 fmol/mg protein or 77 binding sites/cell) and one with low affinity (K_d2 = 2.4 nM) and high capacity (B_max2 = 17.6 fmol/mg protein or 9623 binding sites/cell). In competition experiments, 312 pM [¹²⁵I]-insulin was displaced by cold insulin, IGF-I and IGF-II with IC₅₀ values of 2.2, 7.9 and 20.3 nM, respectively. Glucagon was without effect. Binding of insulin to carp hepatocytes resulted in a significant reduction of glucose release and a significant increase of protein synthesis as of de novo fatty acid synthesis. dedicated to Prof. Dr. W. Hanke on the occasion of his 65^th birthday.  相似文献   

草鱼出血病细胞培养灭活疫苗的研究——疫苗株的免疫原性及其有效免疫剂量的比较   总被引：4，自引：0，他引：4  

杨先乐  夏春  左文功 《水产学报》1989,13(2):138-144

本文比较了疫苗株FR—854和FR—836—w的免疫原性,及其对三寸左右草鱼种的有效免疫剂量。疫苗株FR—854和FR—836—w均有较强的免疫原性,其保护力可达70％以上。但试验结果初步证明,FR—854疫苗比FR—836—w疫苗免疫原性更强。经统计分析,FR—854疫苗的免疫保护力可达88.9±12.0(6)％,血清中和抗体效价为160.5±58.9(6);而FR-838-W疫苗分别只有71.3±14.2(6)％、88.3±26.2(6);二者有显著的差异(0.05>P>0.01)。注射免疫三寸左右的草鱼种,FR—854的免疫剂量在3—5×10~(4.5)TCID_(50)/尾左右,FR—836—w在3—5×10~(7.5)TCID_(50)/尾左右,其免疫保护力可达80％左右,同时我们测得ER—854的半数免疫量为10~(5.1)TCID_(50)/ml。  相似文献   

紫外线诱变建立草鱼抗出血病病原病毒的AHZC88细胞株   总被引：3，自引：1，他引：3  

李亚南  毛树坚 《水产学报》1990,14(2):89-94

通过UV对草鱼出血病病原病毒敏感的草鱼ZC 7901细胞株反覆诱变,获得了对出血病病原病毒具有抗性的AHZC 88细胞株。经生物学特性测定,AHZC 88细胞的染色体2n=48,温度适应范围4°～38℃,最适生长温度27℃,分裂指数在36小时时达最高值。经病原病毒的人工侵染等试验表明,AHZC 88细胞不受草鱼出血病病毒感染。在电镜切片观察中,细胞内不见病毒颗粒。LDH同工酶分析,比敏感细胞少1条酶带。  相似文献   

Summertime and early autumn activity of some enzymes in the carbohydrate and fatty acid metabolism of the crucian carp     

Ylva Lind 《Fish physiology and biochemistry》1992,9(5-6):409-415

In June, July, and September the activities of five enzymes involved in the carbohydrate and fatty acid metabolism, namely phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS), cytochrome oxidase (cyt ox) and 3-hydroxy-acyl-CoA dehydrogenase (HAD), were measured in the heart, liver, red muscle, white muscle, and gill lamellae of crucian carp (Carassius carassius). LDH activity was measured in both reducing (LDHr) and oxidizing (LDHo) directions.The PFK activity in red and white muscle increased significantly between July and September indicating a preparation to winter anoxia by an increased glycylytic capacity in these organs. The HAD activity of the liver had increased significantly (by more than 50%) by September, also a preparation to winter anoxia as HAD is used in the reversed -oxidation (chain elongation of fatty acids). The LDHr and cyt ox activities in the heart and white muscle were highest in July. This shows that both the anaerobic and aerobic capacities are elevated in mid-summer when water temperature is high and oxygen concentration of the water could fluctuate greatly. The LDHo and CS activities in gill lamellae were lowest in July. The results show that the metabolism of crucian carp is under seasonal influence and that a preparation to winter hypoxia/anoxia could be detected in September.  相似文献   

Binding characteristics of the Zn-binding membrane protein from common carp     

Ming-Shyong Wang  Sen-Shyong Jeng 《Fisheries Science》2006,72(2):437-445

ABSTRACT:    This study incorporated the 43 kDa Zn-binding membrane protein isolated from common carp into liposome. The specificity and strength of the binding of ⁶⁵Zn to the 43 kDa protein-liposomes, and the binding of the ⁶⁵Zn-labeled 43 kDa protein-liposomes to laminin were studied. It was found that ⁶⁵Zn was bound to the external side of the 43 kDa protein-liposomes. Specific binding of ⁶⁵Zn to the protein-liposomes was detected. The binding parameter of Zn to the protein was found to be: maximum binding site (N_max), 76.7 pmole/µg protein (approx. 3 mole of Zn²⁺/mole); and equilibrium dissociation constant (Kd), 0.19 µM. Of the cations introduced (Ca²⁺, Cd²⁺,Co²⁺, Cr²⁺, Cu²⁺, Fe²⁺, Hg²⁺, Mg²⁺, Mn²⁺, Ni²⁺, Pb²⁺), only Co²⁺ competed significantly with Zn. The protein-liposomes were also found to bind specifically to laminin with a N_max of 1.1 pmole/µg laminin, and Kd of 4.79 µM. No significant protein-liposome binding occurred to other extracellular matrix proteins (fibronectin, fibrinogen or vitronectin). Furthermore, the binding was specifically inhibited by the Arg-Gly-Asp (RGD) peptide or GRGDSPG, while two other analogs (GRGESPG and GRADSPG) were without effect.  相似文献   

Analysis of the off-flavor risk in carp production in ponds in Dombes and Forez (France)     

D. Vallod  J. P. Cravedi  A. Hillenweck  J. Robin 《Aquaculture International》2007,15(3-4):287-298

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鲢肠道淀粉酶的分离纯化及部分性质研究     

郭彩华  张希春  卢珍华  郑彩梅 《淡水渔业》2007,37(3):34-36

以鲢(Hypophthalmichthys molitrix)加工下脚料为原料,分离提纯其中的淀粉酶并对其部分性质进行了研究。结果表明经多级分离,得到了一种相对分子质量约2.15×104的淀粉酶,命名为SCIG1。SCIG1是鲢肠道淀粉酶的一种,酶活性的最适温度为30℃,最适pH5.5。  相似文献   

Constitutive nitric oxide synthase (NOS) activities in big-head carp (Aristichthys nobilis)     

H.Y. Wong  L.Y. Fung  F. Kwok  S.C.L. Lo 《Fish physiology and biochemistry》1998,19(2):171-179

Nitric oxide synthase (NOS) is an enzyme that catalyzes the formation of nitric oxide (NO), an important biological messenger from L-arginine. There are considerable evidence showing the expression of NOS in mammalian tissues. Information on distribution of NOS activities in various organs and tissues of fish is rare. Non-functional NOS activities were documented in fish semi-quantitatively either by an indirect nicotine-adenine-dinucleotide-phosphate diaphorase (NADPH-d) activity histochemical staining method or by an immunohistochemical method using a cross-reacting antibody to brain NOS. Report on the functional levels of NOS activities in fish is lacking. This report represent the first attempt to document the functional NOS levels in various fish organs and tissues. Constitutive NOS (cNOS) activities in various organs of big-head carp (Aristichthys nobilis) was measured by a chemiluminescence method with a detection limit as low as 10 mol of NO produced. It was found that constitutive NOS activity was highest in the brain, followed by the intestine, stomach, retina, olfactory lobe, swim bladder, skeletal muscle, heart, kidney, ovary and liver. NOS activity could not be detected in the gill filaments. Omission of NADPH in the reaction mixture caused a 57–100% decrease in cNOS activities. However, omission of arginine in the mixture only caused a 56–87% drop in cNOS activities. When compared with cNOS activities documented from other species, a similar pattern of cNOS activities in the various organs and tissues of big-head carp could be seen.  相似文献