This study examined the suitability of Florida largemouth bass (Micropterus salmoides floridanus) for introduction into Virginia and other mid-latitude waters by comparing the performance of northern (M. s. salmoides), Florida, and hybrid largemouth bass in a 342 ha south-central Virginia reservoir, Briery Creek Lake (BcL). Fingerling northern and Florida largemouth bass were stocked into Briery Creek Lake in 1986, following impoundment, and in 1987. Largemouth bass were collected for genotypic and performance analyses in the autumn and spring beginning in 1989 and ending spring 1991. Electrophoretic analyses demonstrated that hybrid largemouth bass (F1 and Fx) dominated the 1987-1990 cohorts and indicated that one or both founding stocks were genetically impure. Comparisons of electroshock catch composition showed no survival advantage for Florida largemouth bass (FLMB) age-1 and older and no differential vulnerability to angling among the four presumptive genotypes of largemouth bass in Briery Creek Lake. Age-O FLMB proportions declined over both winters (1989-1990 and 1990-1991) indicating relatively high first-mortality in the thermal regime of Briery Creek Lake (3,875 annual mean of heating degree days). Statistical comparisons of growth revealed no consistent differences among the respective bass genotypes, although survival and growth tended to be slightly higher for PI hybrid bass. The average total length of largemouth bass in BCL was below the state's average by age three. Total lengths of age-O FI and northern largemouth bass (NLMB) were higher than FLMB and Fx bass in October, perhaps as a result of earlier spawning among NLMB and between the subspecies. Relative weights of largemouth bass in BCL were generally below 95; and few significant differences in (Wr) were observed among the presumptive largemouth bass genotypes. The suboptimal condition (Wr) of largemouth bass in BCL coupled with the decline in growth and condition of bass with increasing age suggested inadequate prey abundance in Briery Creek Lake. Overall, Florida subspecific alleles did not increase in BCL over time, but the population genetic composition shifted toward an Fx mixture in the 1990 year class; future generations of largemouth bass should be dominated by Fx individuals. Results of this study did not demonstrate substantial performance differences among northern and Florida largemouth bass, and their hybrids, except for poorer first-year survival of the Florida subspecies. Therefore, this study provides no support for the continued introduction of Florida largemouth bass in Virginia or other mid-latitude regions. / Master of Science

This thesis examines the reproductive cycles of five species of Texas centrarchids: the largemouthed black bass, the black crappie, the bluegill, the redear sunfish, and the striped bass. In this report attention is given to the reproductive cycles of the five species for a period of one year.

This study is based on the examinations and analyses of 388 largemouthed black bass (Micropterus salmoides) and 118 spotted black bass (Micropterus puctulatus ssp.) which were collected over a period of three years from 9 lakes in the North-Central and East Texas areas. The results should show the following: (1) the average age of the black bass in each of the nine reservoirs in Texas; (2) the growth rate of the bass in these reservoirs; (3) the feeding habits of the bass in all reservoirs studied; (4) a comparison of the growth rates of the largemouthed and spotted basses; and (5) a comparison of the growth rates of bass from Texas and Oklahoma.

Channel catfish have pectoral spines that lock to defend against gape-limited predators such as largemouth bass. Previous work indicated that spines increase survival of channel catfish exposed to bass but did not determine whether bass avoid catfish if less dangerous species are available. We presented bass with channel catfish and two alternatives, bluegill and goldfish, and compared order of ingestion, ingestion time, percent of successful strikes, and time spent chasing each prey species. We also presented the three species in a jar study that standardized position in the water column as well as in a net-pen study. The order of ingestion was suggestive of a preference for goldfish, then bluegill and finally channel catfish. Handling time was greater for channel catfish, less for bluegill, and the least for goldfish. Fewer catfish were eaten when other prey were available. Bass appear to avoid channel catfish if alternative prey is available.

Glacial lakes, such as those in the Midwest region of the United States, are ecologically and economically important, and they provide a wide range of ecosystem services, such as habitat for wildlife and fishes, flood control and recreational boating. Glacial lakes often support locally important sport fisheries, such as largemouth bass <i>Micropterus salmoides</i> and bluegill <i>Lepomis macrochirus</i>,<i> </i>which are partially dependent on suitable habitat within lakes. Nearshore vegetation is often removed by lakeshore landowners for perceived aesthetics and boat access, or by area managers as a form of indirect fisheries management and invasive species control. The connection between nearshore vegetation and fish population health, though widely studied is somewhat unclear. In the two research chapters of this thesis we attempted to further understanding of the environmental factors that influence vegetation abundance and distribution, how vegetation abundance and distribution influences fish population abundance and size structure, and how young-of-year (YOY) largemouth bass utilize habitats within the nearshore environment. In the first research chapter, we used structural equation modeling (SEM) and data collected by the Indiana Department of Natural Resources to quantify the complexity of relationships among catchment characteristics (e.g., catchment size), lake morphology, water quality, vegetation abundance and distribution, and fish population abundance and size structure. Across multiple lakes, lake productivity was more influential in explaining cross-lake variation of largemouth bass and bluegill proportional stock density (PSD) and largemouth bass catch per unit effort (CPUE) than vegetation. This may be a result of the feedback between phytoplankton production and rooted vegetation production. The models we constructed provide insights into the complexity of environmental variables that influence nearshore vegetation and fish populations. In the second research chapter we used stable isotopes (δ¹³ Carbon, δ¹⁵ Nitrogen, δ¹⁸ Oxygen and δ² Hydrogen) to examine the consistency of habitat use and foraging of YOY largemouth bass within Indiana glacial lakes. We observed spatial variation in stable isotope ratios of YOY largemouth bass between habitat types and sites. Additionally, there were significant, positive relationships between δ¹³C of locally collected potential prey items and δ¹³C of YOY largemouth bass suggesting localized foraging patterns. Later in the summer, as young bass grew in size and likely switched to piscivory, we did not observe similar spatial variation in young bass stable isotopes or spatial relationships between prey and the young bass suggesting more homogeneous foraging patterns. Understanding the habitat use patterns of young bass may allow for more efficient and effective management of the nearshore environment. Overall, a greater consideration for the complexity of relationships between nearshore habitat and fish populations may facilitate more effective management.

In fish, maternal stress prior to spawn has been reported to have effects on offspring phenotype. Cortisol, the main glucocorticoid (GC) stress hormone, has been proposed as a potential mediator of such effects because of its organizational role in early teleost development. The present thesis tested whether maternal social stress or treatment with cortisol (as a proxy for maternal stress) prior to spawn affects the cortisol response to stress and anxiety-related behaviours in offspring. In zebrafish (Danio rerio), offspring of dominant females exhibited greater boldness at 6 days post-fertilization (DPF). Interestingly, offspring of females that engaged in social interactions, regardless of the resulting social status of the two females, exhibited greater survival at 1 DPF, a greater fear-related decrease in activity in response to bright light at 6 DPF, and decreased baseline whole-body cortisol content at 0 and 30 DPF. A field experiment with wild largemouth bass (Micropterus salmoides) revealed that maternal cortisol treatment prior to spawn also affected offspring phenotype; offspring of cortisol-treated females had higher masses right after hatch, had greater fear responses, were less bold and less anxious, and exhibited an attenuated cortisol response to an acute stressor. Together, the results of the present thesis suggest that effects of maternal stress prior to spawn on offspring survival, growth, responses to stress, and anxiety-related behaviours are mediated, at least in part, by elevated maternal cortisol but not likely via increased deposition of maternal cortisol into eggs. The effects of maternal stress and cortisol treatment on offspring reported in the present thesis also suggest that maternal stress may prime offspring with adaptive traits to better survive in a stressful environment.

No description available.

Angling practices subject Largemouth Bass Micropterus salmoides to multiple stressors, causing homeostatic physiological disturbances. The combined effects of ambient and live well temperature on stress responses from exercise have not been thoroughly examined. Large numbers of fish required for stress experiments can be produced by intensive culture, but hatchery fish may differ physiologically from wild fish due to dietary carbohydrates. Therefore, the effects of diet, population, and temperature on stress response and health were examined. Stress responses were similar among fish fed formulated and live diets and liver health improved within 4-6 weeks. Although cortisol responses of hatchery and wild fish differed, secondary stress responses were similar. Fish subjected to simulated angling at temperatures of 17, 25, 33 °C with live well temperature differentials of -4, 0, +4 °C, had the lowest resilience to stress at the warmest temperatures, exhausting energy supplies, coincident with metabolic acidosis and poor ion regulation.

No description available.

Populations of largemouth bass, Micropterus salmoides, and bluegill, Lepomis macrochirus, were evaluated from five pit-lakes in Muhlenberg County, Kentucky, to determine if accurate proportional stock density (PSD) data can be obtained from a mandatory creel survey. It was hypothesized that the proportion of stock-to-quality (300-400mm) and quality (+400mm) largemouth bass from four years (2007-2010) of creel survey data would be statistically similar to those generated through on-site sampling in 2011. Fish were collected via a combination of gill netting, seining, hook-and-line fishing, and boat-mounted electro-fishing. In two of the pit-lakes, the sampling-generated length frequency data was not significantly different from the creel survey data (Pump Gadj[1]=0.03, P=0.8629, Goose Gadj[1]=0.76, P=0.3850). There were significant differences between creel and sampling data for the other pit-lakes (Big Reno Gadj[1]=5.74 P=0.0166, Airstrip Gadj[1]=14.3 P=0.0002, Lime Gadj[1]=9.81 P=0.0017). At least one of the lakes likely demonstrated significances because of low sample size (Airstrip and/or Lime). Changes in population structure due to modified harvest regulations may be responsible for the significant differences (Big Reno and Lime). Population structures were verified with relative weight, length-at-age, and an assessment of five years of largemouth bass and bluegill PSD data. It appears that creel survey data does accurately reflect that of simple sampling techniques and can help guide management decisions.