Broken eggs as a cause of infertility of coho salmon gametes     

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 $\text{Na}{}^{\mathrm{+}}\text{K}{}^{\mathrm{+}}$ 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   

Influence of β-hydroxy-β-methylbutyrate on nonspecific humoral defense mechanisms and protection against furunculosis in pikeperch (Sander lucioperca)     

Andrzej K Siwicki  Zdzis&#;aw Zak&#;&#;  John C Fuller Jr    Steven Nissen  Sylwia Trapkowska  Edward G&#;&#;bski  Agata Kowalska  Krzytof Kazu&#;  & El&#;bieta 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   

Mitochondrial NAD(P)-malic enzyme from herring skeletal muscle     

Edward F. Skorkowski  Kenneth B. Storey 《Fish physiology and biochemistry》1988,5(4):241-248

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 K_i (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   

Development of dialysis disequilibrium‐like clinical signs during postobstructive management of feline urethral obstruction     

Cassandra J. Ostroski DVM  Edward S. Cooper VMD  MS  DACVECC 《Journal of Veterinary Emergency and Critical Care》2014,24(4):444-449

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Free water productivity measurements in leaky mariculture ponds     

Richard S. J. Weisburd  Edward A. Laws 《Aquacultural Engineering》1990,9(6):377-403

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   

Mitochondrial NAD(P)-dependent malic enzyme from herring testicular tissue: Purification,kinetic behaviour and regulatory properties     

Edward F. Skorkowski  Kenneth B. Storey 《Fish physiology and biochemistry》1990,8(6):475-484

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 V_max 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   

Diagnosis and management of small-scale fisheries in developing countries   总被引：2，自引：0，他引：2  

Neil L Andrew  Christophe Béné  Stephen J Hall  Edward H Allison  Simon Heck  & Blake D Ratner 《Fish and Fisheries》2007,8(3):227-240

Small‐scale fisheries (SSF) make important but undervalued contributions to the economies of some of the world’s poorest countries. They also provide much of the animal protein needed by societies in which food security remains a pressing issue. Assessment and management of these fisheries is usually inadequate or absent and they continue to fall short of their potential as engines for development and social change. In this study, we bring together existing theory and methods to suggest a general scheme for diagnosing and managing SSF. This approach can be adapted to accommodate the diversity of these fisheries in the developing world. Many threats and solutions to the problems that beset SSF come from outside the domain of the fishery. Significant improvements in prospects for fisheries will require major changes in societal priorities and values, with consequent improvements in policy and governance. Changes in development policy and science reflect these imperatives but there remains a need for intra‐sectoral management that builds resilience and reduces vulnerability to those forces beyond the influence of small‐scale fishers.  相似文献   

Book reviews     

Edward N Ziegler  G. F. Humphrey  Arthur C. Stern  Clarence G. Golueke  Elmer Robinson  T. Viraraghavan 《Water, air, and soil pollution》1979,11(3):401-405

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HIGH-RESOLUTION PARATHYROID SONOGRAPHY     

Erik R.  Wisner  D V M  Dominique  Penninck  DVM  David S.  Biller  DVM  Edward C.  Feldman  DVM  Christiana  Drake  PhD  Thomas G.  Nyland  DVM 《Veterinary radiology & ultrasound》1997,38(6):462-466

The purpose of this study was to assess the diagnostic utility of parathyroid ultrasonography to differentiate causes of hypercalcemia in dogs. We analyzed qualitative and quantitative ultrasound imaging findings and clinical pathology data from 33 dogs that underwent parathyroid ultrasound examination as part of the diagnostic evaluation for hypercalcemia. Diagnoses of the diseases causing hypercalcemia included parathyroid carcinoma (n = S), parathyroid adenoma (n = 15), parathyroid adenomatous hyperplasia (n = 6), chronic renal insufficiency (n = 3), and hypercalcemia of malignancy (n = 4). All parathyroid lesions were round or oval and hypoechoic compared with surrounding thyroid parenchyma. Adenomatous and adenocarcinomatous glands were 4 mm or larger in longest linear measurement on US examination and were statistically significantly larger than hyperplastic glands. (p < 0.001) Linear measurements of parathyroid glands acquired at the time of ultrasound examination correlated well with direct siz determination after surgical excision. (r²= 0.9, p < 0.0001) Parathyroid lesions <4 mm are highly suspicious for parathyroid adenoma or carcinoma, while US lesions <4 mm most likely represent primary adenomatous hyperplasia or secondary parathyroid hyperplasia. Parathyroid size estimation from ultrasound examination is an accurate predictor of true size.  相似文献   

Effect of Protein Source and Concentration on Somatic Growth of Juvenile Green Sea Urchins Strongylocentrotus droebachiensis     

Edward J.  Kennedy Shawn M. C.  Robinson G. Jay  Parsons John D.  Castell 《Journal of the World Aquaculture Society》2005,36(3):320-336

Abstract— An important aspect in the development of any aquaculture industry is the maximization of juvenile somatic growth (i.e., body growth) to reduce production time and increase the size of the final product. In this study, green sea urchins Strongylocentrotus clroebachiensis were fed a prepared diet from 4 December 1998 to 10 September 1999 (i.e., 280 d) in a laboratory to investigate the effect of protein source (soybean andlor fish), protein concentration (20,30,40, and 50% dry mass) and juvenile size (4‐8 mm and 12‐20 mm initial test diameter) on somatic growth. A natural diet of Laminwia longicrurus (i.e., kelp) was used as a reference. There was no difference in initial size among the treatments for either the smaller cohort 1 or the larger cohort 2 sea urchins (6.3 mm and 13.8 mm initial average test diameter, respectively) (P > 0.05 for all tests). After 280 d, the sea urchins fed kelp had an average size of 20.7 mm and 24.5 mm (cohort 1 and cohort 2, respectively). The final average sizes of the sea urchins fed the prepared diets, which did not relate to dietary protein concentrations andlor protein source, ranged from 13.2 mm to 16.2 mm (cohort 1) and from 20.4 mm to 22.9 mm (cohort 2), and were significantly smaller than the kelpfed sea urchins (P < 0.05 and P < 0.001, cohort 1 and cohort 2, respectively). All treatments experienced 95% survivorship or greater. Sea urchin size appears to affect growth rate when optimal conditions for growth are available (i.e., diet and water temperature). As water temperatures increased during the summer of 1999, the sea urchins in cohort 1 fed kelp had a significantly higher growth rate (0.069 dd) than the cohort 2 kelpfed sea urchins (0.052 dd) (P < 0.05). However, within each cohort, there were no significant difference in growth rate (P > 0.05) among the sea urchins fed prepared diets, suggesting sea urchins do not require high concentrations of dietary protein for superior growth, and that plant protein can substitute fish protein in sea urchin diets. Furthermore, the sea urchins fed the prepared diets had poorer test quality and larger gonad yields (13‐22%) compared to the kelpfed sea urchins (4.2%) and a wild sample of sea urchins of similar size (4.0%). The results suggest that the sea urchins fed the prepared diets allocated more energy to gonad production, whereas those fed a natural diet allocated more energy toward test production. To address this gap, more research is required to identify the nutritional components required for test growth that were present in kelp, but appeared to be deficient in the prepared diets.  相似文献