bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of the Soy Isoflavone Genistein on the Reproductive Development of Striped Bass
Authors: Pollack Sara J , Ottinger Mary Ann , Sullivan Craig V , Woods L Curry 
Published: June 2004

Abstract
The aquaculture industry has made great strides toward developing diets for finfish that provide adequate nutrition for the animals being maintained while minimizing the cost to the farmer. Alternative, plant-derived protein sources are used to minimize cost. Soybean meal is the plant protein most commonly used because it maintains adequate growth. However, soy is rich in phytoestrogens, the most abundant of which is genistein. Studies have shown variable physiological effects associated with exposure to genistein. The objective of this research was to investigate the effects of feeding genistein to juvenile striped bass Morone saxatilis at varying concentrations in the diet. The first experiment was designed to determine whether juvenile striped bass are capable of responding to estrogen exposure. Juvenile striped bass were given weekly injections of estradiol benzoate for 3 weeks and showed a significant response to the estrogen via expression of vitellogenin. In two additional experiments, genistein was fed to striped bass fingerlings (approximately 120 d old and 60–100 d old) in varying concentrations (0, 2, 4, and 8 mg/g of diet) to determine whether a similar response would be elicited. No significant differences were found among the growth variables and histological endpoints, although a significant vitellogenin response was observed at the 2-mg/g and 8-mg/g doses. These results show that the juvenile striped bass did respond to the estrogen-like function of genistein and that the genistein induced a U-shaped response curve that is characteristic of the low-dose effects of some endocrine-disrupting chemicals.
Microbial Inhibition in Response to Treatments of Hydrogen Peroxide and Formalin on Landlocked Fall Chinook Salmon Eyed Eggs, as Determined by Scanning Electron Microscopy
Authors: Stephenson Hans , Gabel Mark , Barnes Michael E 
Published: June 2004

Abstract
Scanning electron microscopy was used to compare microbial growth in eggs of landlocked fall chinook salmon Oncorhynchus tshawytscha receiving daily 15-min treatments of 1,667 mg/L formalin, 700 mg/L hydrogen peroxide, or no chemical treatments during incubation in vertical-flow incubators from egg eye-up to hatch. Eggs receiving no chemical treatment had bacterial densities at the end of the experiment that were significantly greater than those on eggs receiving either of the chemical treatments. In eggs not chemically treated, bacterial densities significantly increased from 2,413 bacteria/mm2 on the external egg membrane surface at the start of the experiment to 69,598 bacteria/mm2 12 d later. Although the initial and final numbers were not significantly different, bacterial counts on eggs treated with formalin averaged 2,075 bacteria/mm2 on day 1 and 3,764 bacteria/mm2 by the end of the experiment, while those of eggs treated with hydrogen peroxide ranged from 5,406 bacteria/mm2 at the start of the experiment to 14,431 bacteria/mm2 after 12 d. The number of bacteria attached to the external egg membranes did not differ significantly between eggs treated with formalin and those treated with hydrogen peroxide throughout the study. Fungal growth was negligible and was only observed in control eggs. Additionally, the external membranes of the control eggs, but not the chemically treated eggs, were visibly degraded over the 12-d period. Egg survival was significantly lower in control eggs than in eggs receiving either of the chemical treatments and was significantly correlated with bacterial numbers.
Retrospective Analysis of Antigen Prevalences of Renibacterium salmoninarum (Rs) Detected by Enzyme-Linked Immunosorbent Assay in Alaskan Pacific Salmon and Trout from 1988 to 2000 and Management of Rs in Hatchery Chinook and Coho Salmon
Authors: Meyers T. R. , Korn D. , Glass K. , Burton T. , Short S. , Lipson K. , Starkey N. 
Published: June 2004

Abstract
Five species of anadromous Pacific salmon Oncorhynchus spp. and eight species of nonanadromous fish, including trouts Oncorhynchus and Salvelinus spp., Arctic char S. alpinus, and Arctic grayling Thymallus arcticus (collectively called “trout”), from Alaskan waters were examined by enzyme-linked immunosorbent assay for annual and total prevalences of Renibacterium salmoninarum (Rs) from 1988 to 2000. The total prevalence of Rs antigen was lower among the Pacific salmon and highest among the nonanadromous salmonid species grouped as “trout” that were residents in many of the watersheds. These trout species were likely reservoirs of Rs infection for many of the wild and hatchery stocks of Pacific salmon. Chinook salmon O. tshawytscha and coho salmon O. kisutch comprised 80% of the salmon database, and 45% of these two species were hatchery broodstocks at four facilities where eggs were routinely culled from Rs-positive parent fish. The cyclical occurrences of Rs antigen in the coho and Chinook salmon data sets were remarkably similar and, when combined, were opposite from several of the major peaks and declines observed in the next largest data set, that for sockeye salmon O. nerka. Routine culling of eggs from Rs-positive parent fish supplemented with occasional prophylactic erythromycin therapy appeared to provide some success in Rs management for the three Chinook and two coho salmon hatchery stocks examined. The overall Rs prevalences in spawned adult fish were lower than (or at least not amplified above) those for the remaining coho and Chinook salmon stocks in the database, and no significant epizootics of bacterial kidney disease occurred in progeny fish during juvenile rearing.
The Effect of in Vitro Passage of Infectious Pancreatic Necrosis Virus (IPNV) on Virulence and Sensitivity of the Virus to Rainbow Trout Serum
Authors: Park Kyoung C. , Reno Paul W. 
Published: June 2004

Abstract
Three infectious pancreatic necrosis virus (IPNV) isolates (A1 serotype, Buhl subtype) were passaged five times in rainbow trout gonad (RTG)-2 cells with either minimum essential medium supplemented with 10% fetal bovine serum (MEM-10) or MEM-10 supplemented with 1% rainbow trout Oncorhynchus mykiss serum (MEM−RTS) to determine the effect of passage of the virus on its virulence and sensitivity to RTS. Mortalities in brook trout Salvelinus fontinalis fry were highly variable during viral passages; however, in general, most of the IPNV isolates were virulent under all conditions. The IPNV mortalities ranged between 30% and 89%. Maintenance of virulence during the five passages was dependent on the IPNV isolate and culture conditions. Rainbow trout serum did not always facilitate maintenance of viral virulence during the passages. Isolate mortalities after multiple passages were virulence dependent: the highly virulent isolate showed peak mortality from 4 to 11 d postexposure, while the low-virulence isolate showed delayed peak mortality from 8 to 14 d postexposure. The virus isolates passaged in MEM-10 or MEM−RTS were generally resistant to in vitro inactivation by RTS except for the isolate from noble crayfish Astacus astacus passaged in MEM-10. This isolate became highly sensitive to RTS, demonstrating a reduction in tissue culture infectious dose with 50% endpoint of 10−8.0/mL in virus titer. However, increased RTS sensitivity of the virus did not correlate with decreased virulence. Overall, no relationship was observed between virulence and the RTS sensitivity of the virus. All isolates passaged showed identical monoclonal reaction patterns with a panel of 11 monoclonal antibodies, irrespective of viral virulence and sensitivity to RTS.
California Golden Trout Oncorhynchus mykiss aguabonita Are Susceptible to Proliferative Kidney Disease
Authors: Morris D. J. , Longshaw M. , Adams A. 
Published: June 2004

Abstract
An outbreak of proliferative kidney disease affecting farmed California golden trout Oncorhynchus mykiss aguabonita in the United Kingdom is described. The fish displayed the clinical signs of the disease, such as characteristic swelling of the posterior kidney and spleen. Confirmation of infection with Tetracapsuloides bryosalmonae in the renal tissue was done by means of electron microscopy and immunohistochemistry using a monoclonal antibody specific to T. bryosalmonae.
Inhibitory Effects of Some Antibiotics on Activity of Carbonic Anhydrase from Rainbow Trout Erythrocytes in Vitro and in Vivo
Authors: Hisar Olcay , Hisar Şükriye Aras , Küfrevioĝlu Öirfan , Yanik Telat 
Published: June 2004

Abstract
Carbonic anhydrase (CA) from erythrocytes of rainbow trout Oncorhynchus mykiss was purified by affinity chromatography through a process comprising hemolysate preparation, sepharose- 4B-l-tyrosine-sulfanylamide affinity gel chromatography, and dialysis. Then the effects of three antibiotics—sodium ampicillin, streptomycin, and trimethoprim plus sulfamethoxazole—on this enzyme were investigated in vitro and in vivo. Inhibition effects were determined in vitro by means of the Lineweaver–Burk and activity–antibiotic regression graphs. The dissociation constant of the enzyme inhibitor complex (Ki) and 50% inhibitory values were 2.16 ± 0.40 and 1.87 mM for sodium ampicillin, 7.40 ± 0.310 and 5.21 mM for streptomycin, and 18.50 ± 0.35 and 9.74 mM for trimethoprim–sulfamethoxazole. The in vivo experiment demonstrated that CA was significantly inhibited by trimethoprim–sulfamethoxazole but not by sodium ampicillin and streptomycin.
Photobacterium damselae subsp. piscicida Is Capable of Replicating in Hybrid Striped Bass Macrophages
Authors: Elkamel Ahmad A. , Hawke John P. , Henk William G. , Thune Ronald L. 
Published: June 2004

Abstract
The purpose of this study was to use an in vitro assay to evaluate the ability of Photobacterium damselae subsp. piscicida to survive and replicate within macrophages obtained from hybrid striped bass (striped bass Morone saxatilis × white bass M. chrysops). The results indicated that the number of bacteria recovered from macrophages after 3, 6, 12, and 18 h of incubation increased significantly from time 0 (105, 510, 1,091 and 1,385%, respectively). Replication of the intracellular bacteria was observed at a very low multiplicity of infection (1 bacterium to 100 macrophages). In contrast, the number of Escherichia coli recovered from macrophages declined 47, 80, 91, and 96%, respectively. Light and electron microscopy confirmed the internalization, uptake, and multiplication of bacteria within spacious, clear vacuoles in the macrophages. Using acid phosphatase as a lysosomal marker, we provide evidence that P. damselae subsp. piscicida inhibits phagolysosomal fusion. This study demonstrates that P. damselae subsp. piscicida is a very successful facultative, intracellular pathogen that can survive and multiply within hybrid striped bass macrophages.
Effects of Temperature on the Susceptibility of Largemouth Bass to Largemouth Bass Virus
Authors: Grant Emily C. , Philipp David P. , Inendino Kate R. , Goldberg Tony L. 
Published: June 2004

Abstract
Temperature is an environmental variable thought to influence the susceptibility of fish to infectious diseases. This study demonstrated that juvenile largemouth bass Micropterus salmoides that were experimentally infected with largemouth bass virus (LMBV; family Iridoviridae) experienced greater mortality at 30°C than at 25°C. Juvenile largemouth bass were exposed to equal doses of LMBV and held at three temperatures: 25, 30, and 35°C. Fish held at 30°C suffered mortality at a higher rate than fish held at 25°C and had higher viral loads (viral genomes per gram of tissue) at the time of death. The LMBV-injected fish held at 35°C suffered mortality at rates equal to those of sham-injected controls, suggesting that stressful manipulation at temperatures approaching the upper lethal limit can induce mortality in fish independently of viral infection. These results suggest that temperature is an important determinant of host survival and viral replication in the LMBV system.
Laboratory Efficacy of Amoxicillin for the Control of Streptococcus iniae Infection in Sunshine Bass
Authors: Darwish Ahmed M. , Ismaiel Adnan A. 
Published: June 2004

Abstract
An experimental trial was performed to evaluate the efficacy of amoxicillin in controlling Streptococcus iniae infection in sunshine bass (a hybrid of female white bass Morone chrysops × male striped bass M. saxatilis). Minimum-inhibitory-concentration studies of amoxicillin against multiple S. iniae isolates showed a sensitivity range of 0.0156–0.5 μg/mL. The amoxicillin dose levels tested were 30, 50, 80, and 120 mg of active ingredient per kilogram of fish body weight per day. Administration of medicated feed started 1 d after infection by immersion exposure to S. iniae and continued for eight consecutive days; this was followed by an observation at 15 d posttreatment. Amoxicillin increased the survival rate from 1% in the infected, nonmedicated group to an average of 95% in the infected groups receiving the four doses; there were no significant differences among the medicated groups. Survivors of the infection were not found to be carriers of the bacteria (i.e., there was negative bacterial isolation).
Response of Channel Catfish to Diets Containing T-2 Toxin
Authors: Manning Bruce B. , Li Menghe H. , Robinson Edwin H. , Gaunt Patricia S. , Camus Alvin C. , Rottinghaus George E. 
Published: June 2004

Abstract
The T-2 toxin is a trichothecene mycotoxin produced by certain molds of the genus Fusarium that infect the grains, wheat by-products, and oilseed meals used in the production of animal feeds. An aquarium study was conducted with juvenile channel catfish Ictalurus punctatus. Experimental diets were prepared by replacing the untreated casein in a semipurified diet with casein treated with pure T-2 toxin in the amounts necessary to produce five levels of the toxin. Dietary concentrations were 0, 0.625, 1.25, 2.5, and 5.0 mg/kg of diet. A concurrent study with similarly sized channel catfish was conducted to substantiate the toxicity of the T-2 toxin. This study required feeding the control diet at the same levels of daily consumption (pair-feeding) as in the treatments with the three highest levels of T-2 toxin (1.25, 2.5, and 5.0 mg/kg) to compare differences in weight gain, feed conversion, hematocrit, and survivability. After 8 weeks, significant (P &lt; 0.05) reductions in growth were observed for all treatments fed T-2 toxin compared with the control diet. Significantly poorer feed conversion was found only for the highest level of T-2 toxin. Hematocrit values were adversely affected by the inclusion of T-2 toxin at 1.25, 2.5, and 5.0 mg/kg. Pair-fed catfish had a significantly greater increase in body weight than fish fed the highest level of mycotoxin only. Pair-fed treatments had hematocrit values that were very similar to those of the control and significantly higher than those of fish receiving 1.25, 2.5, and 5.0 mg/ kg. The survivability of the fish fed T-2 toxin at 2.5 and 5.0 mg/kg was significantly lower than that of control fish and their pair-fed counterparts. Histopathological anomalies of stomach, head, and trunk kidneys were observed in fish receiving the three highest levels of T-2 toxin. These results demonstrate that this feed-borne mycotoxin is toxic to juvenile channel catfish.
Preliminary Assessment of the Tolerance and Efficacy of Florfenicol against Edwardsiella ictaluri Administered in Feed to Channel Catfish
Authors: Gaunt P. , Endris R. , Khoo L. , Leard A. T. , Jack S. , Santucci T. , Katz T. , Radecki S. V. , Simmons R. 
Published: June 2004

Abstract
A tolerance study was conducted to determine the palatability of florfenicol to channel catfish Ictalurus punctatus. Four tanks of fish (20 fish/tank) were assigned to each of five treatments distinguished by the amount of florfenicol given in feed per kilogram of body weight, namely, 0, 10, 20, 40, or 100 mg. Fish were fed at a rate of 2.5% of body weight per day for 10 consecutive days. On day 11, all surviving fish were euthanatized, counted, and weighed as a group. Florfenicol- medicated feed was palatable to fish at doses of 10, 20, 40, and 100 mg for 10 consecutive days. All 400 fish were necropsied and examined by histopathology, and no treatment-related changes were observed. In a separate exploratory efficacy study, four tanks (20 fish/tank) were assigned to each of the following treatments: (1) not challenged with Edwardsiella ictaluri and fed unmedicated feed, (2) challenged with E. ictaluri and fed unmedicated feed, (3) challenged with E. ictaluri and fed florfenicol at 10 mg per kilogram of body weight, (4) challenged and fed florfenicol at 20 mg/kg, and (5) challenged and fed florfenicol at 40 mg/kg. Treatment was initiated the day after inoculation, and feed was administered by hand for five consecutive days at 2.5% of body weight. The cumulative mortality observed over a 17-d period in treatment groups 1–5 was 2.5, 57.5, 0, 1.25, and 1.25%, respectively. All 400 fish were necropsied and examined by histopathology. The results indicate that florfenicol was effective in controlling mortality from enteric septicemia of catfish with no adverse treatment-related tissue changes. Florfenicol was palatable, safe, and efficacious in controlling mortality due to infection by E. ictaluri in channel catfish.
Seasonal and Geographic Variation in Juvenile Pink Salmon Diets in the Northern Gulf of Alaska and Prince William Sound
Authors: Boldt Jennifer L. , Haldorson Lewis J. 
Published: June 2004

AbstractFish survival is often determined early in life and can be affected by diet and prey availability. To understand how climate changes affect food web dynamics and salmon survival, it is important to know the types of prey that salmon consume. We describe geographic and seasonal differences in the diets of juvenile pink salmon Oncorhynchus gorbuscha during 3 months of early ocean residence in Prince William Sound (PWS) and the Gulf of Alaska (GOA). Fish were sampled in PWS in July and in the GOA in July, August, and October. The diets and standard lengths of pink salmon varied significantly among stations within each sampling period. There was no discernable geographic pattern in fish length variability. Pink salmon in PWS (July) generally consumed small prey items, such as gastropods, cladocerans, small calanoid copepods, and bivalves, along with some large prey items, such as large calanoid copepods and larvaceans. In August, juvenile pink salmon sampled in the GOA consumed fewer small prey items, and most of their prey biomass consisted of pteropods Limacina spp., larvaceans, hyperiid amphipods, and euphausiids. Prey items consumed by fish sampled in October in the GOA were larger. The prey items that comprised the largest biomass were large pteropods Clio spp., large hyperiid amphipods, euphausiids, crab megalopae, and fish. Prey size increased over the three sampling periods. Fish shorter than 150 mm consumed prey smaller than 3 mg in weight, whereas larger fish tended to consume larger prey weighing up to 16 mg. Pink salmon diets differed among stations as little as 20 km apart.
Local‐Habitat, Watershed, and Biotic Features Associated with Bull Trout Occurrence in Montana Streams
Authors: Rich Cecil F. , McMahon Thomas E. , Rieman Bruce E. , Thompson William L. 
Published: June 2004

AbstractWe evaluated the association of local‐habitat features, large‐scale watershed factors, the presence of nonnative brook trout Salvelinus fontinalis, and connectivity to neighboring populations with patterns of occurrence of threatened bull trout S. confluentus in 112 first‐order to fourth‐order streams in the Bitterroot River drainage in western Montana. Species presence or absence was estimated via single‐pass electrofishing, local‐habitat features were measured in 500‐m sampling reaches, watershed variables were obtained from topographic maps, and potential demographic support from nearby bull trout populations occupying larger main‐stem streams was estimated from electrofishing data records. We defined a set of nine candidate models that represented various combinations of these four main factors and used an information‐theoretic approach to evaluate the relative plausibility of competing models. Models combining local habitat (width, gradient, and woody debris) with brook trout presence and the main‐stem abundance of bull trout and a global model (all variables) were the best approximating models. In contrast, watershed models based on elevation, basin area, and tributary slope and models with local‐habitat or biotic variables alone were poor predictors of bull trout occurrence. Bull trout occurrence was positively associated with channel width, large woody debris, and the presence of a “strong” neighboring main‐stem population and negatively associated with channel gradient and the presence of brook trout. Our findings suggest that bull trout have increased resistance to invasion by brook trout in streams with high habitat complexity and connectivity. Consideration of abiotic and biotic factors at multiple scales, along with a means for ranking their relative importance, is needed to perform more comprehensive assessments of landscape and local influences on species distribution patterns.
Light and Temperature: Key Factors Affecting Walleye Abundance and Production
Authors: Lester Nigel P. , Dextrase Alan J. , Kushneriuk Robert S. , Rawson Michael R. , Ryan Phil A. 
Published: June 2004

AbstractWe used published information to determine optimum light and temperature conditions for walleye Sander vitreus (formerly Stizostedion vitreum) and then applied this simple niche definition to predict how water clarity, temperature, and bathymetry affect walleye habitat availability. Our model calculated thermal–optical habitat area (TOHA), the benthic area of a lake that supplies optimum light, and temperature conditions for walleye during an annual cycle. When water clarity is very low, little walleye habitat exists. As water clarity increases, TOHA for walleye initially increases and then declines exponentially. Optimum water clarity increases with maximum depth of the lake or, in the case of thermally stratified lakes, with thermocline depth. We tested this model by evaluating its ability to account for differences in the sustained yields of walleye fisheries on Ontario lakes. Our results demonstrate that (1) walleye harvest increases in proportion to TOHA times the square root of total dissolved solids, an index of nutrient level, and (2) optimum water clarity for walleye typically exists when Secchi depth is on the order of 2 m. These findings indicate that the increases in water clarity recently observed in the Great Lakes basin (as a result of phosphorus control and dreissenid mussel invasion) have reduced the supply of thermal–optical walleye habitat and, consequently have probably had negative effects on walleye production.