Made available in DSpace on 2017-07-10T14:38:32Z (GMT). No. of bitstreams: 1 Alcione _Refatti.pdf: 576718 bytes, checksum: f91da01987284b0966b64d0b054ca091 (MD5) Previous issue date: 2016-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Abstract Dispersal patterns of early life stages of fish were evaluated in the Iguaçu River at Iguaçu National Park, Brazil-Argentina. Sampling was conducted in the stretch of 20 km, downstream the Iguaçu Falls to the mouth with Paraná River, over three spawning seasons (2011-2014). Higher densities of eggs drifting occurred especially in December, in 2012-2013. The eggs drift was high through all stretch, however, early stage of development was more abundant nearest downstream Iguaçu Falls, while later stages increased into the mouth. The larvae density drift was low, with predominance of preflexion and flexion stages, especially near the Iguaçu Falls. Our results revealed high drift of buoyant eggs highlighting fish spawning in the rapid and turbulent waters of the Iguaçu River, particularly downstream the Iguaçu Falls, and rainfall could be trigger to spawning. Eggs drift passively by rapid flow towards the mouth (5-11hours), probably most of them hatch in the Paraná River, and the larvae disperse to nursery habitats likely in Paraná River. Additionally, inshore zones along the stretch may provide habitats for the larval development / Padrões de dispersão de peixes na fase inicial da vida foram avaliados no rio Iguaçu no Parque Nacional do Iguaçu, Brasil-Argentina. A amostragem foi realizada no trecho de 20 km, da jusante das Cataratas do Iguaçu até a foz com o rio Paraná, ao longo de três estações de desova (2011-2014). Maiores densidades de ovos ocorreram especialmente em dezembro, em 2012-2013. A deriva de ovos foi elevada por todo trecho, no entanto, os estágios iniciais de desenvolvimento foram mais abundantes no trecho mais próximo à jusante das Cataratas do Iguaçu, enquanto os estágios mais avançados aumentaram na foz com o rio Paraná. A deriva de larvas foi baixa, com predominância dos estágios de pré-flexão e flexão, especialmente próximo das Cataratas do Iguaçu. Nossos resultados revelaram elevada deriva de ovos flutuantes destacando a desova dos peixes nas águas rápidas e turbulentas do rio Iguaçu, particularmente a jusante das Cataratas do Iguaçu, e a precipitação pode ser um gatilho para a desova. Ovos derivam passivamente pelo fluxo rápido em direção a foz (5-11horas), provavelmente a maioria deles eclode no rio Paraná, e as larvas provavelmente dispersam para habitats berçários no rio Paraná. Além disso, as zonas costeiras ao longo do trecho podem fornecer habitats para o desenvolvimento larval.

The causative agent of the most devastating honeybee disease, American foulbrood (AFB), is the spore-forming bacterium Paenibacillus larvae. To prevent AFB outbreaks beekeepers prophylactically treat their hives with antibiotics even though it decreases the overall health of uninfected hives. A new treatment for AFB is needed due to recent legislation against using antibiotics, antibiotic resistance developing in P. larvae, and the resilience of P. larvae spores. Bacteriophages, or phages, are an attractive alternative to traditional antibiotics because of their specificity and ability to evolve alongside their target bacterium. In this study, two phage cocktails were developed for the treatment of AFB. The first cocktail was comprised of Brevibacillus laterosporus phages. B. laterosporus is a commensal microbe in most honeybee guts. When treated with B. laterosporus phages, B. laterosporus is induced to produce an antimicrobial toxin to which P. larvae is highly sensitive. Treating AFB infected hives with B. laterosporus phages was able to clear active infections at a rate of 75% as opposed to untreated hives that did not recover. However, B. laterosporus phages did not clear latent P. larvae spores and recovered hives relapsed after treatment. The second cocktail was comprised of P. larvae phages and hives treated with the second cocktail recovered at a rate of 100%, protected 100% of at-risk hives, and treated hives did not relapse with AFB suggesting neutralization of P. larvae spores. A P. larvae phage used in the second cocktail was examined to identify any spore-phage interactions. Results from modified plaque assays, fluorescence from FITC-labeled phages bound to spores, and electron microscopy images all confirm that phages bind to P. larvae spores. Phage therapy for the treatment of AFB is an exciting avenue not only as an alternative to chemical antibiotics, but rather a treatment that can neutralize P. larvae spores.

Brevibacillus laterosporus (B. laterosporus) is a pathogen difficult to distinguish from Paenibacillus larvae (P. larvae), and contributes to Colony Collapse Disorder (CCD) of honeybees. To develop a biocontrol agent to limit its presence, bacteriophages were isolated from Utah County soil samples and used to infect B. laterosporus isolated from Utah County honey and larvae samples. Since CCD is prevalent in Utah beehives, bacteriophage that infect and lyse B. laterosporus may be isolated and characterized. Pathogens were isolated from soil samples, and 16S rRNA gene tests initially identified the strains as P. larvae. Bacteriophages were isolated, purified, and amplified sufficiently to obtain images by electron microscope and genome sequencing by 454 pyrosequencing. Genomes were annotated with DNA Master, a Multiple Document Interface (MDI) program. Open reading frames (ORF's) were compared to the National Center for Biotechnology Information's (NCBI) database of primary biological sequence information via the Basic Local Alignment Search Tool (BLAST) algorithm. Later testing determined the pathogen to actually be B. laterosporus. Plaques demonstrated lytic activity, and electron microscopy revealed bacteriophages of the myoviridae family. The five sequenced genomes were composed of linear dsDNA ranging from 45,552 to 58,572 base pairs in length, 92 to 100 genes per genome, and a 38.10% to 41.44% range of G + C content. Discovering and describing new bacteriophages is a reasonably reproducible process and contributes to appreciating the diverse relationships between bacteriophage, bacteria, and eukaryota. Scientific facilitation of the bacteriophages role in limiting detrimental bacteria may contribute as an adjunctive therapy for CCD.

Microaerobic fermentation (MF) is a process of controlled degradation of organic waste material that occurs in enclosed fermentors under micro-aerobic conditions at near-room temperature. MF processing of vegetal materials progresses to endpoints in about 2-5 weeks. During MF processing, an acidic leachate rich in organic acids and alcohols is produced. The research presented in this thesis focuses on the efficiency of MF pre-processing of feedstock containing fibrous lignocellulosic (FLC) materials; efficiency of microbial and insect larvae-based treatments of MF leachate; tolerance of the Black Soldier fly larvae (BSFL) to various biological inhibitors common in leachate; and effectiveness of using MF and BSFL solid and liquid processing products as agricultural fertilizers. Results indicate that MF is unsuitable for pre-processing of FLC materials. Enhanced MF leachate treatment may increase efficiency of FLC processing though. Leachate can be efficiently treated using BSFL which decrease overall leachate toxicity. BSFL are able to tolerate increased levels of many of the biological inhibitors within the leachate including ethanol, acetate, pH extremes and temperature. MF solid residues increased corn plant growth when amended into soil, but residues resulting from BSFL processing of solid organics stunted corn plant growth. Short-term phytotoxicity of MF leachate was eliminated by diluting it 10 - 10,000 times or through BSFL processing. It can be concluded that MF processing of organics is beneficial for producing solid soil amendments from non-FLC materials and that dilution or BSFL treatment of MF leachate leads to a beneficial liquid fertilizer.

The upper optimum temperature for embryonic development of mountain whitefish is 6 C, and for the post yolk sac stage is 9 to 12 C. The need to know effects on all stages in the life cycle in cases of thermal pollution is demonstrated. Abnormalities caused by thermal pollution in hatched larvae were agape jaws, coloboma or fissure of the eye, monophthalmia or the presence of only one eye, monomicrophthalmia or the presence of one small eye and one case of twinning. High mortalities of eggs occurred at 9 C and higher. Study of the energy expenditure, by the dry weight method showed an energy deficit at 6 and 9 Cat the time of hatching. The larvae are then fully capable of offsetting these deficits by feeding. The oxygen consumption method showed an energy deficit during hatching at 6 C, but failed to show any at 9 C. The efficiency of yolk conversion generally decreased as development progressed. No group effect in active metabolism was observed in the underyearlings. The electrochemical method of measuring oxygen consumption of embryos gave a cumulative value which was 6.8% higher than values obtained using the manometric method. This increase is attributed to the increase in activity of embryos caused by the nature of the experimental set up. Active metabolism and scope for activity were high at 9 and 12 C compared to 6 and 15 C. Standard metabolism steeply increased at 1:5 C. There was very little scope for activity at 15 C. The embryonic development was similar to that of other whitefishes. The mountain whitefish requires more thermal units to reach corresponding stages than does the lake whitefish, after the stage when the blastodisc is prominantly raised up on the yolk.

No description available.

The importance of parental nutritional status on planktotrophic larvae was investigated in both laboratory-conditioned and field (populations) parents of two New Zealand echinoderms: the sea urchin Pseudechinus huttoni and the starfish Sclerasterias mollis. Three questions were addressed: (i) Does parental nutritional status affect the reproductive features (gonad index, gametogenesis, fecundity and biochemical composition) both in the laboratory and under natural conditions? (ii) Does parental nutritional status affect egg characteristics (diameter, number, dry weight, fertilization rate and biochemical composition)? (iii) Are the characteristics of larvae (growth, development, morphology, mortality rate and body composition) influenced by parental or larval nutrition (or both)? To answer the first question, adult P. huttoni and S. mollis were maintained in the laboratory with a low or high diet (in terms of quantity and quality for P. huttoni, and in terms of quantity for S. mollis) for one year. The effect of low and high diets on reproductive features was studied and the same parameters were studied in two parental populations with dissimilar food availability (for P. huttoni: Otago Shelf and Doubtful Sound populations; for S. mollis: Otago inshore and offshore populations). To address the second question, egg characteristics of the laboratory-held and field parents were measured. The third question was answered by rearing larvae of the laboratory and field parents with both low and high concentration planktonic diets. P. huttoni reared in the laboratory with a higher food ration had greater gonad indices and lipid concentration and larger oocyte area. Sea urchins from the Doubtful Sound population had higher food availability, greater gonad lipid concentration and larger oocytes. Parental nutrition had some effect on the characteristics of the egg in P. huttoni. The laboratory-held urchins fed a high diet produced larger eggs: P. huttoni from Doubtful Sound produced larger eggs with a greater carbohydrate concentration. P. huttoni larvae from low-fed laboratory and Otago Shelf parents had faster development The effect of larval nutrition was more important than parental food availability on larval growth and development. Feeding parents in the laboratory had no effect on larval morphology but larvae from Doubtful Sound, which had better food availability, had longer arms relative to body width. A higher cell concentration in the planktonic diet led to shorter larval arm relative to body width. In S. mollis reared in the laboratory, a higher food ration led to larger gonad and pyloric caeca indices. The starfish from an Otago inshore population mainly had a higher gonad index than those from an Otago offshore population. In the laboratory-held parents S. mollis, nutrition had no effect on the egg characteristics. In the field, starfish with higher food availability produced smaller eggs with lower carbohydrate concentration. There was no significant difference between development rates of S. mollis larvae from low and high fed laboratory parents. However, those from the Otago inshore parents, with better food availability, had faster development than the larvae from Otago offshore parents. In S. mollis larvae, the origin of the parents (either from the laboratory or the field) had no effect on larval shape. A higher concentration planktonic diet led to longer larvae relative to body width in larvae from high-fed laboratory parents. In both P. huttoni and S. mollis, parental and larval diet had no effect on rate of instantaneous larval mortality. In both P. huttoni and S. mollis larvae, biochemical composition of the larvae and the egg were different to each other. Egg reserves appear not to be a factor which affects larval characteristics in these species.

Giralang Pond was a water body, with little emergent or submerged vegetation, designed to trap fine sediment and buffer input of rising water to Ginninderra Wetland downstream. Ginninderra Wetland was designed to retain and use sediment nutrients and other potential hazardous materials in urban run-off. Water in the Wetland was more turbid and had lower magnesium concentration, redox potentials and dissolved oxygen concentration than did Giralang Pond. Water temperature was a minimum of 4 °C in the winter and reached a summer maximum of 30 °C Giralang Pond had more organisms but fewer taxa than Ginninderra Wetland. The greatest abundance in the pond resulted principally from high numbers of two numerically dominant species Calamoecia sp. and Micronecta sp.. More organisms were found in vegetated habitats of Ginninderra Wetland than open water habitats. The number of invertebrates and the number of taxa found in Typha domingensis did not differ significantly from similar estimates for Schoenplectus validus, Gambusia qffinis was the dominant predator in both water bodies. On one occasion, G. qffinis reached population densities of 35 individuals per m-2 . G. qffinis was five times more abundant in Gininnderra Wetland than in Giralang Pond and also showed a preference for vegetated areas. G. qffinis over-grazed it's prey on several occasions. G. qffinis, invertebrate predators and prey followed a pattern of a community in a stable predator-prey cycle. Prey in early spring increased population numbers and then decreased when G. qffinis and other predators increased their numbers. The pattern was further strengthened by occurring in both areas of open water and vegetated habitat types.

Bibliography: leaves 176-189 / xiii, 223 leaves, [2] leaves of plates : ill. (2 col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 1987

Black rockfish (Sebastes melanops) is an important marine recreational species throughout the Pacific Northwest. Recent catch data indicate a trend of age-truncation in the black rockfish population off the Oregon coast, with older females rapidly disappearing from the population. In populations with broad age distributions, older fish may contribute disproportionately to larval production through a variety of mechanisms. Thus, the removal of older age classes through fishing may impact the population far beyond the simple loss of biomass. We tested the hypothesis that older females produce higher quality offspring, or offspring otherwise more capable of survival, than those from younger females. Mature female black rockfish of various ages were captured live and held until parturition. Larvae were then reared under identical conditions to compare performance in terms of growth, starvation, and mortality. Results indicate that older females produce offspring that grow faster in both length and weight, survive longer in the absence of an exogenous food supply, and exhibit lower mortality rates than offspring from younger mothers. This difference in larval performance may be explained by the relatively greater amount of endogenous energy reserves present in the oil globules of offspring from older mothers. Larval oil globule volume at parturition was significantly related to all larval performance factors and was strongly correlated with maternal age. Given the difference in larval quality, it is critical for the management of black rockfish, and possibly other species as well, that these older individuals not be addressed solely in terms of biomass, but their relative reproductive contribution and the repercussions of their removal from the population be considered. / Graduation date: 2004