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At least 1,657 records · Page 92Linked to original sources
USGS2012

Assessing consumption of bioactive micro-particles by filter-feeding Asian carp

Silver carp Hypophthalmichthys molitrix (SVC) and bighead carp H. nobilis (BHC) have impacted waters in the US since their escape. Current chemical controls for aquatic nuisance species are non-selective. Development of a bioactive micro-particle that exploits filter-feeding habits of SVC or BHC could result in a new control tool. It is not fully understood if SVC or BHC will consume bioactive micro-particles. Two discrete trials were performed to: 1) evaluate if SVC and BHC consume the candidate micro-particle formulation; 2) determine what size they consume; 3) establish methods to evaluate consumption of filter-feeders for future experiments. Both SVC and BHC were exposed to small (50-100 μm) and large (150-200 μm) micro-particles in two 24-h trials. Particles in water were counted electronically and manually (microscopy). Particles on gill rakers were counted manually and intestinal tracts inspected for the presence of micro-particles. In Trial 1, both manual and electronic count data confirmed reductions of both size particles; SVC appeared to remove more small particles than large; more BHC consumed particles; SVC had fewer overall particles in their gill rakers than BHC. In Trial 2, electronic counts confirmed reductions of both size particles; both SVC and BHC consumed particles, yet more SVC consumed micro-particles compared to BHC. Of the fish that ate micro-particles, SVC consumed more than BHC. It is recommended to use multiple metrics to assess consumption of candidate micro-particles by filter-feeders when attempting to distinguish differential particle consumption. This study has implications for developing micro-particles for species-specific delivery of bioactive controls to help fisheries, provides some methods for further experiments with bioactive micro-particles, and may also have applications in aquaculture.

Journal of Aquaculture Research & Development↗
USGS2013

Accuracy of stream habitat interpolations across spatial scales

Stream habitat data are often collected across spatial scales because relationships among habitat, species occurrence, and management plans are linked at multiple spatial scales. Unfortunately, scale is often a factor limiting insight gained from spatial analysis of stream habitat data. Considerable cost is often expended to collect data at several spatial scales to provide accurate evaluation of spatial relationships in streams. To address utility of single scale set of stream habitat data used at varying scales, we examined the influence that data scaling had on accuracy of natural neighbor predictions of depth, flow, and benthic substrate. To achieve this goal, we measured two streams at gridded resolution of 0.33 × 0.33 meter cell size over a combined area of 934 m2 to create a baseline for natural neighbor interpolated maps at 12 incremental scales ranging from a raster cell size of 0.11 m2 to 16 m2 . Analysis of predictive maps showed a logarithmic linear decay pattern in RMSE values in interpolation accuracy for variables as resolution of data used to interpolate study areas became coarser. Proportional accuracy of interpolated models (r2 ) decreased, but it was maintained up to 78% as interpolation scale moved from 0.11 m2 to 16 m2 . Results indicated that accuracy retention was suitable for assessment and management purposes at various scales different from the data collection scale. Our study is relevant to spatial modeling, fish habitat assessment, and stream habitat management because it highlights the potential of using a single dataset to fulfill analysis needs rather than investing considerable cost to develop several scaled datasets.

Journal of Geographic Information System↗
USGS2018

Rearing performance of juvenile brown trout Salmo trutta fed a bioprocessed soybean meal diet with differing velocity regimes

This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets (46% protein, 16% lipid) and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary protein source for the reference diet, which was compared to a bioprocessed soybean meal ingredient that replaced approximately 67% of the fishmeal in the experimental diet. At the end of the experiment, there were no significant differences in gain, percent gain, feed conversion rates, nor specific growth rates between the dietary treatments. There were also no significant differences in intestinal morphology, splenosomatic, hepatosomatic, and viscerosomatic indices related to diet composition. However, gain, percent gain, feed fed, and specific growth rate were all significantly greater in brown trout reared at the higher velocity. No significant differences in any of the other variables measured were observed between the velocity treatments. There were no significant interactions between diet and velocity in any of the variables. Based on the results of this study, bioprocessed soybean meal can replace at least 67% of the fish meal in brown trout diets, regardless of the rearing velocities used in this study. Higher rearing velocities are recommended to maximize juvenile brown trout growth rates.

Open Journal of Animal Sciences↗
USGS1969

On the use of magnetic cleaning in paleointensity studies

The use of partial alternating field demagnetization and, to a lesser extent, partial thermal demagnetization has been found useful as a means of removing secondary components of magnetization from rocks used in certain methods of determining paleointensities. During the course of this investigation, which was carried out on lavas erupted during historic times, it was also learned that a partial remanence characterized by relatively low coercivity possessed blocking temperatures throughout the blocking temperature spectrum. On the other hand, a partial remanence characterized by low blocking temperatures possessed only low coercivity.

Hawaii↗
USGS1974

Seasonal variation of the upper digestive tract yeast flora of feral pigeons

Feral pigeons were sampled over a 16-month period to determine whether their normal yeast flora varied according to season. Candida albicans and Saccharomyces telluris occurred during the entire sampling period, with C. albicans reaching its highest levels between August and January and S. telluris peaking from March through May. Candida krusei was present for 10 months but exhibited no predictable variation in density. Candida tropicalis , C. guilliermondii and Geotrichum were isolated on several occasions while C. lusitaniae , C. pseudotropicalis and Torulopsis glabrata were each isolated once. The high levels of infection and frequency of occurrence of some yeast species make the feral pigeon highly suspect as a carrier and disseminator of potentially pathogenic yeast.

Journal of Wildlife Diseases↗
USGS1974

Trichomoniasis in the Hawaiian barred dove

Two barred doves found in the south Kona district of the island of Hawaii were diagnosed as having trichomoniasis on the basis of gross and microscopic lesions. This brings the confirmed list of columbid species susceptible to natural trichomoniasis to four and is the first report of the disease from columbids in the Hawaiian Islands.

Hawaii↗
USGS1976

Blood values of the canvasback duck by age, sex and season

Blood samples were obtained from canvasback ducklings from Manitoba and Saskatchewan and from immature and adult canvasbacks on the Mississippi River near LaCrosse, Wisconsin and the Chesapeake Bay. These samples were used to determine baseline data on red cell counts, hematocrit, total protein, glucose, cholesterol, hemaglobin and distribution of plasma proteins. Calculations were also made to determine mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. The major differences noted were between ducklings and adults. The former having higher total protein and lower hematocrit, glucose and cholesterol values. These hematologic values were collected in order to provide baseline information on apparently healthy canvasbacks, thereby providing disease investigators with a standard of comparison.

Canada, United States↗
USGS1983

Outbreak of avian cholera on the wintering grounds of the Mississippi Valley Canada goose flock

Avian cholera is reported for the first time in Canada geese, Branta canadensis , of the Mississippi Valley population. The disease was detected in weekly surveillance transects and was responsible to the loss of about 850 geese during the winter of 1978–1979 at localized areas in southern Illinois. Necropsies performed on 480 geese that died at Union County Conservation Area and on 133 birds at Horseshoe Lake Conservation Area during January and February 1979 revealed that the majority of losses (649%) were caused by avian cholera. Lead poisoning was responsible for the death of 14% of the geese analyzed and the remaining 22%, most of which were decomposed, were undiagnosed. Lethal lead levels and Pasteurella multocida occurred concomitantly in a few instances.

Illinois↗
USGS1987

Immunization of salmonids against Yersinia ruckeri: Significance of humoral immunity and cross protection between serotypes

Brook trout ( Salvelinus fontinalis ) were immunized with bacterins containing either Serotype 1 or 2 isolates of Yersinia ruckeri to determine the relative degree of cross-protection afforded when the fish were challenged with the homologous or heterologous serotype. While fish immunized with pH-lysed bacterins produced highly specific agglutinins that did not cross-react with antigens derived from a heterologous serotype of Y. ruckeri all fish were protected against experimental challenge, regardless of which serotype was used for bacterin production and experimental challenge. Other experiments indicated that brook trout injected intraperitoneally with highly specific antibodies could not be passively immunized against experimental challenge.

Journal of Wildlife Diseases↗
USGS1989

Fusarium mycotoxins from peanuts suspected as a cause of sandhill crane mortality

An estimated 9,500 sandhill cranes (Grus canadensis) died in Gaines County, Texas and Roosevelt County, New Mexico between 1982 and 1987. The predominant clinical sign observed in sick cranes was their inability to hold their heads erect, both while standing and flying. Multiple muscle hemorrhages and submandibular edema were the most common lesions seen at necropsy. Mycotoxins produced by Fusarium sp. growing during cold, wet weather on peanuts left in the field after harvest, the predominant foods of the dead cranes at the time of these mortality events, were identified as the most likely cause of this mortality. Rendering moldy peanuts inaccessible to the cranes by conventional tillage resulted in reduced crane mortality in these areas.

New Mexico, Texas↗
USGS1991

Isolation and phenotypic characterization of an oxidase-negative Aeromonas salmonicida causing furunculosis in coho salmon (Oncorhynchus kisutch)

An oxidase-negative Aeromonas salmonicida was isolated from coho salmon ( Oncorhynchus kisutch ) suffering from an epizootic of furunculosis at the state hatchery near Belfair, Washington. Typical, oxidase-positive A. salmonicida was isolated concurrently from the same population of fish. Mortality was controlled with medicated feed treatments. Evidence supporting the identification of the two types of A. salmonicida is presented. Methods for the proper identification of oxidase-negative A. salmonicida isolates are evaluated.

Journal of Wildlife Diseases↗
USGS1991

Poisoning of Canada geese in Texas by parathion sprayed for control of Russian wheat aphid

Approximately 200 Canada geese ( Branta canadensis ) died at a playa lake in the Texas Panhandle shortly after a winter wheat field in the basin adjacent to the lake was treated with parathion to control newly invading Russian wheat aphids ( Diuraphis noxia ). No evidence of infectious disease was diagnosed during necropsies of geese. Brain ChE activities were depressed up to 77% below normal. Parathion residues in GI tract contents of geese ranged from 4 to 34 ppm. Based on this evidence, parathion was responsible for the goose mortalities. Parathion applications to winter wheat will undoubtedly increase if parathion is applied for control of both Russian wheat aphids and greenbugs ( Schizaphis graminum ). Geese may potentially be exposed to widespread applications of parathion from fall to spring, essentially their entire wintering period.

Texas↗
USGS1994

Isolation of Aeromonas salmonicida from paddlefish, Polyodon spathula

Aeromonas salmonicida was isolated from paddlefish ( Polyodon spathula ) mortalities collected during an epizootic of furunculosis at the Spring River State Hatchery, Arkansas (USA), in 1992. Isolates of the bacterium were obtained from culture of gill and kidney tissue. This is the first epizootic of bacterial etiology to be reported in paddlefish.

Arkansas↗
USGS1970

Challenge infection as a means of determining the rate of disease resistant Trichomonas gallinae-free birds in a population

Trichomonas gallinae -free pigeons and mourning doves were infected with the Jones' Barn strain of T. gallinae to determine the rate of disease resistant T. gallinae -free birds in each population. Although all birds became infected 88% of the pigeons were resistant to trichomoniasis while 82% of the mourning doves were resistant. It was concluded that these birds had been previously infected and spontaneously lost their trichomonad fauna while retaining their resistance to fatal infection.

Journal of Wildlife Diseases↗