bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fish Diversity and Abundance in Relation to Interannual and Lake‐Specific Variation in Abiotic Characteristics of Floodplain Lakes of the Lower Kaskaskia River, Illinois
Authors: Shoup Daniel E. , Wahl David H. 
Published: October 2009

AbstractThe importance of floodplain lakes to tropical river systems is well established, but little is known about the function of these habitats in temperate river systems. We examined fish diversity, abundance, and reproduction within six oxbow lakes of the Kaskaskia River, Illinois, over 5 years and their relationship to 11 abiotic environmental variables. The lakes were hydrologically dynamic within and among years, varying in the time connected with the main stem (0‐22 weeks/year) and the frequency of low (<0.3‐m) water (0‐23 weeks/year). Differences were found both among years and lakes. All measured limnological variables (dissolved oxygen, Secchi disk depth, conductivity, and temperature) varied temporally, but only conductivity and Secchi disk depth varied among lakes. Fish species differed among lakes and between adjacent lotic habitats, and species‐specific abundance varied among years, seasons, and lakes. This variation was related to several environmental variables. Diversity was positively related to the distance between the oxbow lake and the river but not to any variables that had interannual variation. Seine catch per unit effort (CPUE) was negatively related to mean water level and Secchi disk depth. Total electrofishing CPUE was not related to any variables; however, that of bluegills Lepomis macrochirus was positively related to maximum depth and that of warmouths L. gulosus was positively related to vegetated area. Across all lakes, evidence of reproduction was found for five species and was negatively related to the mean water level and frequency of low water and positively related to flood periodicity. The oxbow lakes have the potential to contribute to the fish community of the main river by providing spawning and nursery habitat for several fish species as well as helping maintain several less abundant main‐stem species. However, when considering management options to maintain or restore these ecosystem functions, interannual variation in environmental variables, particularly those related to flood periodicity, should be considered.
Hearing Sensitivity of the Walleye Pollock
Authors: Mann David A. , Wilson Christopher D. , Song Jiakun , Popper Arthur N. 
Published: October 2009

AbstractThe hearing abilities of three age‐groups (which correspond to size‐classes) of walleye pollock Theragra chalcogramma were determined from auditory evoked potentials. Walleye pollock had the best hearing sensitivity from 100 to 200 Hz, with thresholds around 75 dB re: 1 μPa. Hearing sensitivity decreased with increasing frequency up to 450 Hz. There was no significant difference in hearing sensitivity between the age‐groups, although there was a significant interaction between frequency and age as well as a trend in which the older fish had slightly lower mean thresholds. At the same time, there was a substantial increase in the size of the saccular otolith and associated sensory epithelia of the inner ear, suggesting that a large increase in ear size does not lead to a large change in hearing sensitivity. In addition, there was an effect of water temperature on the hearing thresholds at 350 Hz, whereby each degree of temperature (°C) increase resulted in an 8.3‐dB decrease in hearing threshold. The results suggest that the hearing thresholds of walleye pollock are generally similar to those of other gadid fishes. This knowledge can be used to evaluate the potential impact, in terms of behavioral responses or physiological effects, that various human‐generated sounds (e.g., seismic survey and underwater radiated vessel noise) may have on this species.
Interspecific Resource Competition between the Invasive Round Goby and Three Native Species: Logperch, Slimy Sculpin, and Spoonhead Sculpin
Authors: Bergstrom Margot A. , Mensinger Allen F. 
Published: October 2009

AbstractThe invasive round goby Apollonia melanostomus (formerly Neogobius melanostomus) has negatively affected benthic fish communities throughout the Great Lakes. In this study, we compared the sensory physiology and behavior of three native species—slimy sculpin Cottus cognatus, spoonhead sculpin C. ricei, and logperch Percina caprodes—with those of the round goby to determine the mechanisms that allow the round goby to dominate native fish. The reaction and strike distances of the four species were examined during predator‐prey trials using natural amphipod prey Gammarus spp. under varying light intensities (0‐130 lx) to compare input from the mechanosensory lateral line and visual systems. Trials in the dark (0 lx) indicated that the sculpins and the round goby had similar lateral line sensitivity. However, all three native species had a significant advantage in reaction and strike distance over the round goby at higher light intensities. Interspecific resource competition was assessed by pairing a round goby with a native fish in an artificial stream. Round gobies gained significantly more weight than the native fishes during all trials. Slimy sculpins were able to maintain their weight in the presence of the round goby; however, spoonhead sculpins and logperch lost a significant amount of weight during the trials. These experiments indicate that although the round goby does not possess an inherent sensory advantage, it can dominate resources and outcompete native fish. Thus, round gobies may pose risks for a wide variety of native benthic fishes.
Migration Characteristics of Hatchery and Natural Spring Chinook Salmon Smolts from the Grande Ronde River Basin, Oregon, to Lower Granite Dam on the Snake River
Authors: Monzyk Fred R. , Jonasson Brian C. , Hoffnagle Timothy L. , Keniry Patrick J. , Carmichael Richard W. , Cleary Peter J. 
Published: October 2009

AbstractSmolts of spring Chinook salmon Oncorhynchus tshawytscha experience substantial mortality while migrating through free‐flowing reaches of the Snake River basin before reaching Lower Granite Dam, the first dam encountered in the Columbia‐Snake river hydrosystem. We investigated the patterns of travel time and survival of hatchery and natural smolts fitted with passive integrated transponder (PIT) tags through specific reaches of the migration corridor during the 2000‐2006 migration years for two populations originating in the Grande Ronde River basin (Lostine River and Catherine Creek). For both populations, median travel times for natural smolts were significantly longer in the upper reaches of the migration corridor but shorter in the lower reaches than for their hatchery counterparts. Also, among both hatchery and natural smolts, smaller individuals spent more time in the upper reaches, presumably feeding to attain a larger size before continuing their migration. Within populations, both hatchery and natural smolts showed similar patterns of survival through the reaches of the migration corridor above Lower Granite Dam. Size‐selective mortality was evident for hatchery and natural smolts from both populations, especially in the upper reaches, larger individuals experiencing higher survival. The Catherine Creek population experienced the majority of natural and hatchery smolt mortality (32.8‐65.8%) in a relatively short (91‐km), low‐gradient reach immediately below the summer rearing habitat. In contrast, the Lostine River natural and hatchery smolts experienced lower mortality (3.6‐46.1%) in a 174‐km reach below the summer rearing habitat. The results of this study demonstrate the dynamic nature of survival and migration rate among spring Chinook salmon smolts during their initial seaward migration from tributaries.
Shifts in the Trophic Ecology of Brook Trout Resulting from Interactions with Yellow Perch: An Intraguild Predator‐Prey Interaction
Authors: Browne David R. , Rasmussen Joseph B. 
Published: October 2009

AbstractIn size‐structured populations, predator‐prey interactions may be preceded by a phase of resource competition earlier in ontogeny, with potential consequences for population dynamics and resource management. We hypothesized that brook trout Salvelinus fontinalis and yellow perch Perca flavescens would compete for shared resources and interact as predator and prey. We used stable isotopes and stomach content analysis to compare the trophic ecology of brook trout in lakes with and without yellow perch. Percent littoral resource use by brook trout differed between perch and nonperch systems, ranging from approximately 50% to 100% in nonperch lakes compared with 10‐70% in perch lakes. Nonpiscivorous‐sized brook trout (fork length [FL] < 25 cm) showed a significant ontogenetic diet shift toward greater pelagic resource use during growth from 15 to 25 cm in sympatry with yellow perch. Nonpiscivorous‐sized brook trout in nonperch lakes consumed a mixture of zoobenthos, zooplankton, and littoral prey fish. In contrast, in lakes containing yellow perch, nonpiscivorous‐sized brook trout fed primarily on pelagic prey. Brook trout shifted to piscivory at a FL of approximately 25 cm in both perch and nonperch systems. Isotopic results and stomach content analysis indicated that yellow perch were the primary prey of piscivorous‐sized brook trout (FL > 25 cm) in perch lakes, occurring in 66‐100% of the brook trout sampled and accounting for over 97% of the diet by weight. Overall, the presence of yellow perch resulted in a shift in the energetic basis for brook trout production from primarily littoral to primarily pelagic. The shift in brook trout food web position was associated with a decline in brook trout catch per unit effort. We conclude that brook trout and yellow perch interact as intraguild predator and prey and that the interaction is dominated by yellow perch.
Effects of Common Carp on Reproduction, Growth, and Survival of Largemouth Bass and Bluegills
Authors: Wolfe Matthew D. , Santucci Victor J. , Einfalt Lisa M. , Wahl David H. 
Published: October 2009

AbstractThe common carp Cyprinus carpio was introduced to North America more than a century ago, but little research has focused on interactions between this invasive species and native fishes. We used large mesocosms (600 m2) within drainable 0.4‐ha ponds to examine the effects of adult common carp on (1) reproduction of largemouth bass Micropterus salmoides and bluegills Lepomis macrochirus and (2) growth and survival of the larvae and juveniles of these centrarchid species. In separate enclosures, adult bluegills or largemouth bass were stocked with or without common carp. In enclosures with common carp, turbidity was substantially higher, but both centrarchid species spawned and the densities and sizes of larval largemouth bass and bluegills were similar to those of larvae in enclosures without common carp. As juveniles grew, largemouth bass survived at a higher rate but were smaller in enclosures containing common carp compared with largemouth bass in enclosures without common carp. In a second experiment, we stocked known numbers of older juvenile centrarchids into enclosures and found decreased growth for both largemouth bass and bluegills. However, survival of largemouth bass was again higher in enclosures with common carp. Although centrarchid spawning was successful and larval growth and survival did not decrease in the presence of common carp, centrarchid growth slowed at the juvenile stage, probably due to food resource limitation resulting from direct competition with common carp for invertebrate forage, high turbidity caused by common carp, or both of these factors.
Evaluation of Long‐Term Retention and Detection of Oxytetracycline Marks in Walleye Otoliths Using Genetic Methodology
Authors: Logsdon Dale E. , Miller Loren M. , Anderson Charles S. 
Published: October 2009

AbstractBecause neither genetic population assignments nor oxytetracycline (OTC) mark identifications are 100% accurate, genetic methods were modeled alone and in combination with OTC mark observations to identify the source of walleyes Sander vitreus in a supplemented population and to evaluate the accuracy of OTC mark examination in distinguishing stocked fish that had been treated with OTC from those produced naturally in the lake. Readers examined otoliths from 3,663 fish from two year‐classes that were sampled up to 5 years after stocking. A subset of 1,578 of the examined individuals were also assigned to source populations based on genotypes at eight microsatellite loci using baseline genetic data from the stocking source and the recipient population (the measure of genetic divergence [FST] = 0.07 between populations before stocking). The models indicated that OTC mark observation errors occurred in all samples and that the error rates varied among samples and readers. Model estimates of overall false‐negative error rates ranged from 11.4% to 17.2%, and estimates of overall false‐positive error rates ranged from 8.9% to 16.7%. Over the ages of walleyes inspected (3 months to age 5), there was neither a systematic increase in mark errors with age nor a decrease in mark intensities; thus, the OTC marks present at 3 months appeared to be permanent. Any true mark absence was due to inefficient OTC immersion treatment or the loss of a successfully applied mark before the first sample was inspected as fingerlings. The presence of both false positives and false negatives in all samples indicates that mark detection error did consistently contribute to the overall mark error rates. Thus, changes in quality control are justified for both OTC immersion treatment and mark detection procedures.
American Shad Feeding on Spawning Grounds in the St. Johns River, Florida
Authors: Harris Julianne E. , McBride Richard S. 
Published: October 2009

AbstractWe evaluated the feeding habits of American shad Alosa sapidissima on spawning grounds in the St. Johns River, Florida. Feeding intensity in freshwater was generally low but highly variable. The items consumed were mainly pelagic (cyclopoid copepods and woody debris), although benthic (mollusks and sand) and surface (adult insects [Coleoptera, Hemiptera, and Odonata]) organisms occurred occasionally. The stomach fullness index varied by location for males, suggesting that ingestion is related to prey availability. Feeding by females also varied by location and continued during final oocyte maturation and active spawning. Egg cannibalism was suggested by the presence of some eggs morphologically similar to American shad eggs in the stomachs of males and females collected when females were running ripe. The results from diel sampling suggested that individuals consumed approximately 1.727 kJ/d in freshwater, which represents only a small fraction of the estimated daily energetic expenditure during the spawning run. Unlike iteroparous populations, Florida's American shad probably do not conserve energy for out‐migration. While this low incidence of freshwater feeding did not maintain fish weight, it may increase available energy and thereby increase fecundity.
The Structure of Complex Biological Reference Points and the Theory of Replacement
Authors: Rothschild Brian J. , Jiao Yue 
Published: October 2009

AbstractThe percent spawning‐stock biomass per recruit (PSSBR) is a commonly used biological reference point (BRP). Justification for using specific values of PSSBR as BRPs has largely been based upon graphical interrelations of (1) the dependence of recruitment on stock, (2) the dependence of stock on recruitment (i.e., replacement), and (3) the dependence of spawning‐stock biomass on fishing mortality. This paper provides analytic solutions of these interdependencies. Analytic solutions are provided for equilibrium and nonequilibrium cases: (1) fixed recruitment and fixed mortality, (2) fixed recruitment and variable mortality, and (3) variable recruitment and variable mortality. The analysis is used to develop equations for both the “replacement line” and a full recruitment→stock→recruitment cycle. The analysis clarifies the connection between iteroparous and semelparous populations in both equilibrium and nonequilibrium settings. The analytic derivations provide the opportunity to conduct research on optimization of the equations and set the stage for field and laboratory studies of the dependence of stock on recruitment, complementing the much more intensive studies of the dependence of recruitment on stock.
Evaluation of the Sampling Efficiency of Three Otolith Sampling Methods for Commercial King Mackerel Fisheries
Authors: Chih Ching‐Ping 
Published: October 2009

AbstractThe aims of this study were to (1) compare the efficiency of two widely used otolith sampling methods: The random otolith sampling method (ROS) and the age‐length key sampling method (ALK); (2) explore whether a new otolith sampling method, the reweighting method (REW), provides more efficiency than either the ROS or ALK methods; and (3) incorporate the concept of effective sample size into sampling design. The REW differs from the ALK in that the REW has larger sampling intervals and reweights the estimated age‐frequency distribution with the length‐frequency distribution instead of building an age‐length key. Bootstrapping approaches were used to analyze the precision of age‐frequency distributions derived with these three methods (1) when otolith samples were sampled directly from a simulated population of king mackerelScomberomorus cavallaand (2) when king mackerel samples were collected via two‐stage cluster sampling, which is the sampling method commonly used in the field. The results showed that when samples were selected directly from the simulated king mackerel population the age‐frequency distributions derived from the REW samples had slightly better precision than those estimated from the ROS and ALK samples. However, when cluster sampling was used the efficiency of the REW and ALK greatly exceeded that of the ROS. This is because the nonindependence among fish samples in individual trips makes the effective sample sizes much smaller than the actual sample sizes. The problem of nonindependence of otolith samples can be avoided when the ALK or REW is used. Overcoming the nonindependence problem of the ROS requires a number of otolith samples that can exceed the number needed for the ALK or REW by several times. Thus, the ROS is the least cost‐effective among the three sampling methods examined, while the REW provides the best combination of efficiency and flexibility.
A study of selected phytoestrogens retention by reverse osmosis and nanofiltration membranes - the role of fouling and scaling
Authors: Dudziak Mariusz , Bodzek Michał 
Published: October 2009

AbstractFouling and scaling are common phenomena that accompany membrane filtration and are caused by the presence of organic and inorganic matter in water, which may affect the removal of low-molecular mass organic micropollutants. Comparative filtration of deionized water containing selected phytoestrogens (biochanin A, daidzein, genistein, and coumestrol) was carried out using one new membrane and one contaminated with organic or inorganic matter. Two commercial Osmonics DS membranes were selected for the research, reverse osmosis DS3SE and nanofiltration DS5DK. Filtration was carried out in the dead-end mode. Higher removal of phytoestrogens was caused by reverse osmosis and retention depended on the molar mass of the compound. The decrease in membrane efficiency associated with fouling or scaling brings about an increase in the retention coefficient of phytoestrogens during both reverse osmosis and nanofiltration. The highest increase in phytoestrogen retention was found for the nanofiltraton membrane which was more susceptible to fouling than the osmotic one. This confirms the effect of membrane porosity on the phenomenon studied. The increase in micropollutants removal observed after fouling or scaling was caused by the modification of the membrane surface, hindered diffusion of the compound, and intensified or limited adsorption of micropollutants on the membrane surface.
Factors influencing detection of Potato Leafroll Virus and Potato Virus Y in potato tuber extracts
Authors: Treder Krzysztof , Przewodowski Włodzimierz , Barnyk Agnieszka 
Published: October 2009

Factors influencing detection of Potato Leafroll Virus and Potato Virus Y in potato tuber extracts
Detection of Potato leafroll virus (PLRV) and Potato virus Y (PVY) directly in potato tubers has been influenced by several factors. The most important were: the place of tuber sampling, preincubation of tuber sap before loading into wells of microplate and duration of tubers storage after collecting from field. The concentration of both viruses was highest in the heel part of tubers, whenever tested. Preincubation of tuber sap for several hours improved true/false signal ratio for dormant tubers and enabled reliable detection of both viruses. However after natural dormancy breaking it was necessary to change Cocktail-ELISA procedure to obtain reliable results, consistent with DAS-ELISA on leaves. The sap was not preincubated but loaded into wells directly after sample collecting and immuno-enzymatic reaction was developed overnight in refrigerator.
Equine recurrent uveitis: A clinical manifestation of leptospirosis
Authors: Frellstedt L. 
Published: October 2009

SummaryLeptospirosis is a zoonosis of worldwide distribution affecting domestic animals, wildlife and man. The bacterial disease is caused by pathogenicLeptospiraspp., which are transmitted from reservoir hosts to accidental hosts. Horses are accidental hosts and can become susceptible to leptospiral infections. Widespread exposure to leptospires exists and is significantly more common than clinical disease.Leptospirosis can have different clinical manifestations including abortion, still birth, systemic disease with hepatic or renal dysfunction, and equine recurrent uveitis (ERU). ERU is the most frequently encountered clinical manifestation and this article will focus on the review of leptospira‐associated ERU.Equine recurrent uveitis is the most common cause of vision impairment and blindness in horses. The pathogenesis of leptospira‐associated ERU involves direct bacterial effects and immune‐mediated responses. Clinical signs vary between the acute and chronic phases of the disease and progress over time. The diagnosis of leptospira‐associated ERU can be difficult and usually requires a combination of diagnostic tests. Medical and surgical treatments have been described with varying outcomes. The prognosis for sight is usually poor, although core vitrectomy may improve the outcome. Avoidance of leptospiral exposure of horses is the only reliable prevention of leptospira‐associated disease.
Epithelioid variant of haemangiosarcoma in a gelding
Authors: Dawson D. R. , Scrivani P. V. , Schaefer D. M. W. , Bogdanovic L. B. , Ainsworth D. M. 
Published: October 2009

SummaryThis case report provides a clinical description of an epithelioid variant of haemangiosarcoma in a horse. Haemangiosarcomas are rare neoplasms in equids, and only recently have the pathological aspects of the epithelioid variant in horses been described. Despite performance of cytology and surgical biopsy, theante mortemdiagnosis was incorrect in this case, demonstrating the common problem with diagnosing this neoplasm due to the lack of overt vascular differentiation. Due to the deteriorating condition of the patient, no antineoplastic treatment was attempted. Apost mortemcomputed tomography helped characterise the invasive nature of the tumour. Only withpost mortemsampling was the diagnosis of epithelioid variant of haemangiosarcoma discovered.