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61.
62.
Kelly W. Wilcox Joachim Stoss Edward M. Donaldson 《Aquaculture (Amsterdam, Netherlands)》1984,40(1):77-87
Egg content originating from ruptured ova progressively reduced the success of fertilization in coho salmon (Oncorhynchus kisutch) eggs. The salmon egg differs in ionic composition from the ovarian fluid in exhibiting higher K+ and Mg2+ and lower Na+ concentrations. Normal ovarian fluid induced spermatozoan motility whereas ovarian fluid contaminated with egg content progressively lost the ability to induce motility. Loss of motility was related to decreasing ratios in the ovarian fluid, indicating that reduced fertility may be caused by inactivation of sperm cells in the insemination medium. Removal of contaminated ovarian fluid by rinsing ova in isotonic media induced spermatozoan motility and restored fertility completely. The use of an isotonic NaHCO3 solution for rinsing of ova is suggested as a routine procedure for artificial insemination in salmonids where the presence of broken eggs is suspected. 相似文献
63.
Andrzej K Siwicki Zdzisaw Zak John C Fuller Jr Steven Nissen Sylwia Trapkowska Edward Gbski Agata Kowalska Krzytof Kazu & Elbieta Terech-Majewska 《Aquaculture Research》2006,37(2):127-131
Studies have shown that in both in vitro and in vivo tests, β‐hydroxy‐β‐methylbutyrate (HMB) increases the nonspecific cellular and humoral immune response and protection against diseases in animals. The present study examines the influence of HMB on nonspecific humoral defense mechanisms and protection against furunculosis in pikeperch (Sander lucioperca). β‐hydroxy‐β‐methylbutyrate was fed in a pelleted ration of 50 mg kg?1 feed day?1 for 4 weeks. Blood was drawn from 12 HMB‐fed and control‐fed pikeperch. The lysozyme and ceruloplasmin activities in the plasma, total immunoglobulin (Ig) levels, and total serum protein were analysed prior to and then after 2 and 4 weeks of HMB ingestion. After 4 weeks of HMB ingestion, a challenge test was performed by injecting the fish with live pathogenic Aeromonas salmonicida bacteria. β‐hydroxy‐β‐methylbutyrate at a dose of 50 mg kg?1 feed resulted in a statistically significant (P<0.05) increase in the lysozyme activity of the plasma, total Ig, and serum protein levels. Additionally, reduced mortality (40%) after the in vivo challenge with pathogenic A. salmonicida suggested that HMB‐activated nonspecific protection against furunculosis in pikeperch. 相似文献
64.
Mitochondrial NAD(P)-dependent malic enzyme [EC 1.1.1.39, L-malate: NAD+ oxidoreductase (decarboxylating)] was purified from herring skeletal muscle to a specific activity of 8.2 mol/min/mg. The purification procedure involved chromatography on DEAE-cellulose, Red Agarose and a Sephacryl S-300 with a final recovery of 38% of enzyme activity. This enzyme catalyzes the oxidative decarboxylation of malate in the presence of either NAD or NADP in the presence of Mn2+. Some kinetic characteristics of this enzyme were determined. The pH optimum of activity is 7.0. ATP was shown to be a competitive inhibitor with malate. The inhibition by ATP displayed hyperbolic competitive kinetics with a Ki (ATP) of 0.28 mM in the presence of NAD and 0.75 mM in the presence of NADP. Fumarate reversed ATP inhibition.In vivo, regulation of NAD(P)-dependent malic enzyme might respond to changing levels of mitochondrial ATP and fumarate with the enzyme undergoing kinetic activation by an increase in the concentration of mitochondrial fumarate which could reverse enzyme inhibition by ATP. 相似文献
65.
66.
Laura Gmez-Montes Zaul García-Esquivel Louis R. D'Abramo Armando Shimada Carlos Vsquez-Pelez María Teresa Viana 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):769-780
Juvenile green abalone Haliotis rufescens were grown under laboratory conditions at 21±1 °C and fed formulated diets consisting of different protein:energy ratios (mg protein/kcal), 62, 74, 85, 100, 108, for 60 days. The level of crude protein ranged from approximately 26% to 44% while the energy content remained constant at about 4.1 kcal g−1. Growth ranged from 3.63 to 12.33 mg day−1. The growth of abalone fed the 100 and 108 diets was significantly greater than that of each of the other diets. Protein efficiency ratio increased as the dietary protein content increased except for the T108 diet (44% crude protein). Abalone apparently consume food to satisfy an energy requirement. Caloric expenditure due to metabolism was estimated for abalone fed diets with protein ratios of 62, 85, 100. Energy loss due to respiration did not vary appreciably among abalone fed the different diets. The proportional distribution of dietary energy into fecal, digestible, growth, and metabolic energy was estimated for abalone fed these diets. Apparent dry matter digestibility was among the lowest for abalone fed the 100 P:E diet, but growth of abalone fed this diet was significantly higher than that of each of the other treatments except the 108 diet. Unexplained energy loss to achieve balance ranged from 7% to 28.5%, some of which is probably due to differential mucus and ammonia production. Results suggest a potential for the reduction of both dietary protein and lipid without causing any adverse effects on the growth response. 相似文献
67.
68.
69.
The rate of net organic productivity in experimental shrimp mariculture ponds was determined via free water methods for each hour over a two month period in late summer 1985. Automated measurements of pH and temperature served as the basis for development of a mass balance budget for dissolved inorganic carbon. Pond surface area and volume changed with depth in a complex but predictable fashion. The seepage rate, which is a quantitatively important term in the inorganic carbon budget, was determined with the salt mass balance. Seepage rates averaged 136–182 mm day−1 (23–37% of pond volume per day). Close agreement between evaporation rates, independently determined from water budgets for each of the four adiacent ponds, demonstrated that the calculated seepage rates were accurate. All four ponds were net producers of organic matter despite the fact that three of the four received additions of allochthonous organic matter. Net productivity averaged 14–65 mmol C m−2 day−1. 相似文献
70.
Mitochondrial NAD(P)-dependent malic enzyme [EC 1.1.1.39, L-malate: NAD+ oxidoreductase (decarboxylating)] was purified from herring testicular tissue to a specific activity of 26.4 μmol NADH/min/mg
protein. Herring testicular tissue is one of the most abundant sources of this enzyme. The purification procedure involved
differential centrifugation of mitochondria and then chromatography on DEAE-Sephacel, Red Agarose and Sephacryl S-300. This
enzyme catalyzes the oxidative decarboxylation of malate in the presence of Mn2+ and either NAD or NADP. Under Vmax conditions the ratios for the rate of NAD/NADP reduction was 1.8. A study of the reductive carboxulation reaction indicated
that this enzyme reaction is reversible; at pH 7.0 the reverse reaction exhibited 22% of the activity of forward reaction.
Some kinetic characteristics of the enzyme were determined. ATP was found to be a competitive inhibitor with respect to malate.
Fumarate reversed ATP inhibition. Regulation of NAD(P)-dependent malic enzyme from herring testicular tissue mitochondria
could respond to changing levels of mitochondrial ATP and fumarate in vivo. 相似文献