A 10 x 10 factorial mating design and a ‘common-garden’ rearing approach were employed to examine genetic effects and heritability of growth, carcass-quality traits, and disease resistance, important production traits in the aquaculture of hybrid striped bass (♀ white bass, Morone chrysops, crossed with ♂striped bass, Morone saxatilis). Genotypes at four to ten nuclear-encoded microsatellites were used for parentage assignment and a general, linear-mixed model and a Restricted Maximum Likelihood (REML) algorithm were used to estimate variance components associated with dam, sire, and dam x sire interaction effects. Dam and sire effect on juvenile growth (weight, length and growth rates) were significant, whereas dam by sire interaction effect was not. Estimates of broad-sense heritability for growth, based on family means (h2 f), in dams ranged from 0.60 ± 0.20 to 0.82 ± 0.10 and in sires ranged from 0.43 ± 0.20 to 0.75 ± 0.18. High correlations were found between growth rates measured at two time intervals. Estimates of general combining ability for growth rates differed significantly among dams and among sires, whereas estimates of specific combining ability for each dam × sire combination did not differ significantly from zero. These results suggest that additive-effect genes contributed to the differences in juvenile growth. Dam and sire effect on fillet weight were significant; dam effect on liver weight and sire effect on total viscera weight were also significant. Dam and sire effect on hepatosomatic index and viscerasomatic index were significant, as was dam and sire interaction effect on viscerasomatic index. Phenotypic and genetics correlations between body weight and carcass-quality traits were high (0.85 - 1.00). Phenotypic correlations between body weight and standardized carcass-quality traits were positive but low, ranging from 0.07 to 0.19. Resistance to S. iniae was assessed in a challenge experiment, using the 10 dam x 10 sire factorial mating design. A significant effect of sire on resistance to S. iniae was found, and offspring from one sire had a 2.4 times higher probability of dying than offspring from the ‘average’ sire. Genetic effects on the immune-response parameters and on stress-response parameters assessed were non-significant.

The US hybrid striped bass (Morone chrysops x M. saxatilis) industry has been negatively impacted by infectious diseases because there are very few approved drugs and vaccines. Therefore, a series of experiments was conducted to explore the potential use of various dietary supplements including autolyzed brewers yeast, the commercial prebiotic GroBiotic®, oligonucleotides and levamisole for improvement of hybrid striped bass growth, immunity and resistance to disease caused by various pathogenic bacteria. In two trials with brewers yeast, fish fed diets supplemented with yeast at 2% generally showed enhanced weight gain and feed efficiency compared with those fed a basal diet. Brewers yeast also positively influenced resistance to S. iniae infection. In addition, results of immune response assays demonstrated that brewers yeast can be administered for relatively long periods without causing immunosuppression. GroBiotic® (Grobiotic) also resulted in significantly enhanced weight gain, innate immune responses and resistance of juvenile hybrid striped bass to S. iniae infection. An additional experiment with sub-adult fish showed significantly reduced mortality of fish fed a diet supplemented with GroBiotic® at 2% when subjected to an in-situ Mycobacterium marinum challenge. This is the first report of positive effects from dietary prebiotics for fish health management, although many fundamental questions should be pursued further. Dietary supplementation of a commercial oligonucleotide product (Ascogen P®) at 0.5% of the diet was shown to enhance resistance of hybrid striped bass against S. iniae infection and increased their neutrophil oxidative radical production. However, the effect on growth was marginal. Dietary levamisole supplementation at a low level (100 mg/kg) enhanced the growth and feed efficiency of juvenile hybrid striped bass. However, an elevated dosage (1000 mg/kg diet) strongly suppressed growth, feed intake and feed efficiency. Hypothesized beneficial influences, including antibody production and resistance to S. iniae and A. hydrophila were not substantiated. Although dietary levamisole increased fish macrophage respiratory burst, an in vitro study failed to show a direct effect on cultured macrophages. This suite of studies demonstrated the potential use of some dietary supplements to enhance hybrid striped bass production. Thus, immunonutrition represents a valuable strategy to apply in aquaculture.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains viii, 113 p. : ill. (some col.), col. map. Vita. Includes abstract. Includes bibliographical references.

Master of Science / Department of Biology / Martha E. Mather / Determining patterns and drivers of organismal distribution and abundance are fundamental and enduring challenges in ecology, especially for mobile organisms at a ‘scape scale. To address the problem presented by individuals whose distributions are dynamic across large geographic areas, here I tracked 59 acoustically-tagged migratory striped bass (Morone saxatilis) with an array of 26 stationary receivers in Plum Island Estuary (PIE), MA. Specifically, I asked (1) how these predators were distributed across the estuarine seascape, (2) if these fish used three types of geomorphic sites (exits, confluences, and non-confluences) differently, (3) if distinct types of individual distributional “types” existed, and (4) if fish within distinct distributional groups used geomorphic site types and regions differently. Based on three components of predator trajectories (site specific numbers of individuals, residence time, and number of movements), striped bass were not distributed evenly throughout PIE. Confluences attracted tagged striped bass although not all confluences or all parts of confluences were used equally. Use of non-confluences sites was more variable than exits or confluences. Thus, geomorphic drivers and regions link mobile organisms to physical conditions across the seascape. Based on spatial and spatial-temporal cluster analyses, these striped bass predators clustered into four seasonally-resident distributional types. These included the (1) Rowley River group (fish that primarily resided in the Rowley River), (2) Plum Island Sound group (fish that primarily resided in the Middle Sound region), (3) Extreme Fidelity group (fish that spent most of their time in PIE at a single receiver location), and (4) the Exploratory group (fish that showed no affiliation with any particular location). These distributional groups used geomorphic site types and regions differently. Thus, my data show a rare link between behavioral (i.e., individual animal personalities) and field ecology (seascape geomorphology) that can advance the understanding of field-based patterns and drivers of organismal distribution.

The aspects of the biology of Aeromonas hydrophila with respect to a striped mullet (Mugil cephalus L.0 nursery were examined. A. hydrophila density in the natural water was found to be strongly correlated with turbidity and weakly correlated with water temperature. No correlations were found between A. hydrophila density and water depth, dissolved oxygen, pH, total alkalinity, specific conductivity, or phytoplankton chlorophyll concentration. A. hydrophila density/g dry weight of stomach content were found to be correlated with chlorophyll concentration/g dry weight stomach content. The survivability of striped mullet after capture was found to be primarily related to stress. Stressed striped mullet tended to become infected by A. hydrophila more readily. The mortality of transported striped mullet was reduced with the use of quinaldine, a fish tranquilizer, and by reducing crowding during transport.

The movements of Western Chorus Frogs (Pseudacris, triseriata triseriata) were studied from March, 1970, to March, 1971, at the Robert H. and Esther L. Cooper Woodland Area near Muncie, Delaware County, Indiana. The objectives of the study were to determine: (1) the time and rate of dispersal from the breeding pool; (2) the day-to-day movements, including the time and minimal distance traveled; (3) the preferred cover or microhabitat; and (4) the site of hibernation.Seventy-three Chorus Frogs were tagged with approximately 50 μc Co60 and toe-clipped, and each was released at its capture site. The frogs were then sought at intervals by surveying the area with a portable survey meter equipped with a scintillation probe. The location of each recovered specimen and a description of the recapture site was recorded.Sixty-two individual specimens were recaptured at least one time. The number of recaptures for each specimen was variable, and the maximum number of recaptures for a single specimen was 26 times. In all, 324 recoveries of tagged specimens were made. The tagged specimens graduallybecame lost to the investigator, and the last specimen was found on August 4. The longest period of contact for an individual frog was 134 days.Some Chorus Frogs began leaving the breeding pools soon after the first eggs were observed on April 1. The exodus appeared to be gradual as a few (one to eight) additional tagged specimens were found out of the pools throughout April and early May. Four of these specimens returned at least once to their original pool and seventeen frogs entered a second pool.From a single attempt to monitor the overnight activities of these frogs, it appears that they remain quiescent during the daylight hours and become active between dusk and dawn.The minimal distances traveled by the tagged, specimens during the study are more a function of the length of the contact period and the number of recaptures than of the activity of the frogs. The average rate of movement for all of the specimens over the entire study period was 11.3 feet/day. However, the fastest observed rate of movement for a single specimen between two recapture sites was 138 feet/day. The greatest straight distance any specimen was found from its original pool was 700 feet. Most recaptures were within 500 feet of the pools where the specimens were tagged.In 213 (91.3%) of the 234 recaptures made daylight hours after the frogs left the breeding pools,the frogs were hidden in the leaf litter of the woods or dead grasses of the grassland. In the remaining recaptures the frogs were hidden under small objects. The frogs seemed to prefer moist rather than dry or wet cover, but this is possibly more a reflection of conditions at the time of the study than a preference on the part of the frogs.The gradual disappearance of the tagged frogs from the study area, the woodland situation of the breeding pools, and the concentration of searching efforts in the vicinity of the pools prevented the determination of the preferred habitat type (woodland or grassland). Also, because of the loss of all tagged specimens by the end of summer, hibernating sites were not located.There is evidence that the gradual disappearance of tagged specimens may be explained by predation or movement of the frogs underground or out of the study area. Other frogs lost their cobalt wires and could no longer be located.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 134-143). Also available via the Internet.

Comparative ecology and interspecific competition were examined between two sympatric congeners, Sebastes caurinus Richardson 1845 (copper rockfish) and S. maliger (Jordan and Gilbert 1880) (quillback rockfish) in Saanich Inlet, British Columbia, Canada, from 1986-1990. Ecological profiles were constructed through analyses of depth distribution, habitat and species associations, activities, feeding habits, gut allometry, growth, and reproduction. Interspecific competition between copper and quillback rockfish was examined by experimentally manipulating the densities of one or the other species on rocky reefs in Saanich Inlet where they were sympatric. The Pisces IV submersible was used to survey the distribution of rockfish in relatively deep-water (21-140 m) in Saanich Inlet. Copper and quillback rockfish were sympatric in water depths of 21-65 m. They occurred in association with one another the majority of the time (>90%) and their densities were greatest over areas of complex substrate. Size of copper and quillback rockfish was positively correlated with increased depth, primarily due to the absence of small fish in deeper waters. Both species were observed most frequently perched on open substrate or hovering in the water column. Copper rockfish were observed swimming more frequently than quillback rockfish. Copper and quillback rockfish primarily consumed demersal crustaceans throughout the year. Copper rockfish consumed a greater proportion of pelagic fishes than quillback rockfish, whereas quillback rockfish had a greater proportion of pelagic crustaceans in their diet. Levins' (1968) measure of niche breadth of the diet (by mass), as standardized by Hurlbert (1978), was narrow (0.19-0.20) to moderate (0.32-0.51) for quillback and copper rockfish respectively, during spring, summer, and fall. In the winter it was extremely narrow (0.02) for both species due to their feeding predominantly on one prey type, juvenile herring (Clupea harengus) . The Simplified Morisita Index of niche overlap (Horn 1966) in feeding habits (by mass) was relatively high (>0.55) throughout the year, and particularly during the winter (0.99). This high niche overlap in the winter occurred when large schools of juvenile herring were available in the environment and were probably not a limited resource. Extensive niche overlap between copper and quillback rockfish may therefore indicate an abundance of a shared resource rather than competition for the resource. Copper and quillback rockfish consumed the greatest quantity of food during the winter when feeding on juvenile herring, although quillback rockfish consumed significantly less food mass than copper rockfish in the winter. A greater proportion of quillback rockfish were collected with food in their stomachs during the spring and summer, when the numerically dominant food items were pelagic crustaceans. The importance of fish prey in the diets of both copper and quillback rockfish increased with size. Copper rockfish had a shorter intestine and larger stomach relative to similar-sized quillback rockfish. This suggested that the gastrointestinal tract of copper rockfish was better suited to holding and digesting fish and larger crustaceans than quillback rockfish, an observation consistent with differences in their feeding habits. Copper and quillback rockfish had similar growth patterns with no readily identifiable species-specific and sex-specific differences. Both sexes of both species attained asymptotic lengths of 30-31 cm total length and had similar growth coefficients (0.141-0.187). Within each sex, copper rockfish had a smaller increase in mass per unit of body length than quillback rockfish, indicative of a more pelagic lifestyle for copper rockfish. Estimated lengths at first and 100% sexual maturity for female and male copper and quillback rockfish were similar. Male copper rockfish were ripe, and potentially inseminated females, in January and February. Female copper rockfish were found to be carrying fertilized eggs in April and May, and gave birth to their young primarily in June. The reproductive cycle of quillback rockfish preceded that of copper rockfish by approximately one month, with parturition for quillback rockfish occurring mainly in May. The fecundity of copper and quillback rockfish was similar, with a 30-cm fish giving birth to approximately 90,000 young. Visceral fat cycles of mature female copper and quillback rockfish were complementary to their cycles of gonad maturation and increases in gonad size, indicating that they use visceral fat stores as a source of energy for maturation of their eggs and nourishment of their developing young. Visceral fat cycles of mature males were mainly coincident with the maturation and size increase of their gonads, indicating that they did not use visceral fat reserves in the maturation of their gonads. Male rockfish secondarily may have used their fat reserves as an energy source during the period when they were ripe, perhaps for mating activities. Visceral fat accumulation and dissipation in immature males and females appeared to be primarily related to periods of feeding. Interspecific competition between copper and quillback rockfish was asymmetrical, seasonal, and transitory, based on experimental manipulations of the densities of the congeners in natural populations. Copper rockfish did not have a competitive effect on quillback rockfish, but quillback rockfish had a weak competitive effect on copper rockfish. This effect was apparent only during the fall, was strongest in the fall immediately following the density manipulations, and appeared to weaken in the subsequent fall season. The seasonal competitive effect may have been caused by copper rockfish moving onto the study reefs (18-31 m depth) from shallower waters (<20 m) during the fall and winter, creating a short-term 'ecological crunch' in which food or space resources were limited. Overall, comparative ecological profiles of copper and quillback rockfish exhibited a large degree of overlap. Differences observed between them were small but consistently indicated that copper rockfish had a more pelagic lifestyle than quillback rockfish. The otherwise high degree of similarity between the two congeners, however, did not translate into sustained interspecific competition. Ecological theory purporting a major role for interspecific competition in structuring fish communities was therefore not supported by experimental manipulations of population densities of deep-subtidal, temperate zone rockfishes. The asymmetrical, seasonal, and transitory occurrence of weak interspecific competition demonstrated that competition between these rockfish species is dynamic, and cannot account for the pattern of species association. Alternative hypotheses based on the importance of intraspecific competition, predation, or environmental variability must therefore be considered. / Graduate

The method for the determination of total mercury in biological material described in this paper comprises a destruction of organic matter by wet digestion, a reduction of the mercury by stannous sulfate, and circulation of the displaced mercury vapor in a closed system directly connected with an atomic absorption spectrophotometer Seven tissues from ten samples of locally obtained Roccus saxatilis (striped bass) were analyzed, and a three-fold elevation of mercury levels in the liver over the levels in the filet noted. See Table XIX for a comparison of the high, low, and average values for each tissue.

This is the first study to assess how the coastal migratory stock of striped bass (Morone saxatilis) uses non-natal New England estuaries during their foraging migration. Using hydroacoustic telemetry from June through October in Plum Island Estuary, Massachusetts, I examined how long coastal migratory striped bass stayed throughout the seasons, if they were equally distributed, if individual striped bass were distributed differently, and if distribution changed with season, tide, or light. Striped bass, ages 2-5 (300-480 mm), were tagged with VEMCO transmitters in the spring and summer of 2005 (N=14) and 2006 (N=46). They stayed for an average of 66 days in 2005 (SE=7.6) and 72 days in 2006 (SE=6.2). Of the fish tagged in 2005 and 2006, 60% remained for longer than 30 days. This might reflect two striped bass migration strategies: 1) transient migration, in which striped bass visit many estuaries, and 2) estuary-specific, in which they reside in a single location for the summer. The amount of time the striped bass spent in six reaches delineated within the estuary was quantified. Striped bass were not evenly distributed across these reaches. Instead, they spent the most time in the mid Plum Island Sound and lower Rowley River reaches in both years. Three different uses of PIE were observed. Some striped bass stayed briefly (5-20 d; N=24), some stayed primarily in the Rowley River (N=14), and others stayed primarily in Plum Island Sound (N=22). Striped bass use of the mid Plum Island Sound and lower Rowley River reaches remained consistently high in spring and summer, but decreased in fall, while use of the lower Plum Island Sound did not vary much. Use of other reaches varied seasonally. Tide and light were less associated with distribution, but in the summer the Rowley River use-group increased utilization of tidal creeks during the day, though not at high tide. These three use-groups identified in Plum Island Estuary may be foraging contingents that may learn how to forage in specific parts of the estuary demonstrated by over half the striped bass remaining for much of the summer and congregating in distinct areas.