Hatchery supplementation of declining fish populations is used for increasing year-class strength, particularly when fish are released with knowledge of local predators. The ability of young-of-the-year lake sturgeon (Acipenser fulvescens) to avoid predation, as well as their vulnerability to predation, remains undocumented. The objective of my thesis was to determine: 1) whether hatchery-reared, predator-naive juvenile sturgeon would respond to alarm cues from injured conspecific cues, a reliable indicator of predation risk in other fishes; and 2) if sturgeon would learn to identify unknown predators through a Pavlovian-like conditioning with conspecific alarm cues. Releaser-induced recognition learning is a variant of Pavlovian learning in which recognition of a previously neutral stimulus is acquired through the experience of pairing a behaviourally active releasing stimulus and a novel stimulus. Sturgeon were initially conditioned using a behaviourally active stimulus of sturgeon alarm cue, paired with a behaviourally neutral stimulus of novel northern pike (Esox lucius) odour, or were pseudo-conditioned with distilled water paired with pike odour. Following conditioning, sturgeon were tested for recognition of the predator odour 24 hours later. The first population of fish (Rainy River) showed a dramatic antipredator response to alarm cues from the skin of conspecifics, but failed to exhibit learning of a novel predator through conditioning with alarm cues obtained from the skin of conspecifics. However, when Rainy River fish were conditioned with alarm cues from the whole body of conspecifics, they showed strong learning of the predator. Conditioning Wolf River fish to recognize predators with whole body extract had no effect on response to predator odours. However, when the fish were conditioned multiple times there was evidence of predator learning. These results highlight potential opportunities and limitation to life-skill training of artificially reared sturgeon for future conservation initiatives.

Sturgeon fish (Acipenseriformes) is commercially used to produce high quality fish meat and highly priced caviar. In fact, all species of Sturgeon fish are integrated into CITES appendix. Sturgeon (Acipenser baerii) is the most frequently bred/reared and the most commercial representative of its kind, not only in Europe but also in Asia. The aim of this final project is to evaluate international sturgeon trade while using CITES references from 1998-2012. The source of data(s) was commercial database CITES. Over the last 15 years, we have exported and imported almost 5000 tons and 32 million pieces of all species. During this monitored period the frequency/traffic of the trade increased. The mostly traded forms were fish eggs which were exclusively destined/designated for commercial purpose and came from those specimens which were reared in captivity - (94% from commercial activity). People mostly traded sturgeon in these forms : (1) eggs, (2) caviar, (3) extracts,(4) derivatives, (5) fish meat and others. In the last 3 years, the trade intensity in fish eggs markedly decreased. On the contrary, since 2008 there was an annual growth of/in the sale of caviar. France was not only the country of origin but also the country where there was the largest/greatest/biggest volume of market. Germany was one of the main export countries, while Armenia , if we take the quantity (kg) into account. On the other hand, The U.S. was the main import country. Sturgeon was exported in the greatest quantity to Moldavia. During the period of time mentioned above, The Czech Republic exported only twice (35 000 pieces) and imported (210 pieces) of living specimen.

In Sachsen gewinnt die Aufzucht von Stören in Teichen zunehmend an Bedeutung, insbesondere um die Wirtschaftlichkeit der Warmwasserteichwirtschaft zu verbessern. Mit der Störerzeugung wurden Kapazitäten für die Herstellung von Farmkaviar geschaffen. Dieser ist jedoch starken Qualitätsunterschieden unterworfen. Störe neigen zu einer starken Verfettung des Eingeweidekomplexes, des Filets und der Gonaden, was geschmackliche Probleme zur Folge hat. Es wurde untersucht, ob spezielle Futtermittel, die für die finale Aufzuchtphase von Stören angeboten werden, geeignet sind, die Kaviarqualität zu verbessern und der Verfettung entgegenzuwirken. Mit allen vier geprüften Futtermitteln konnten gute Zuwachsleistungen und eine Verbesserung der Produktqualität erreicht werden. Alle Futtermittel erwiesen sich als geeignet für die Störaufzucht in der finalen Aufzuchtsaison vor der Kaviargewinnung. Die eingesetzten Futtermittel hatten jedoch weder Einfluss auf die zu gewinnende Menge, noch auf die Qualität des Kaviars.

Žuvininkystė Lietuvoje turi gilias tradicijas. Tai viena seniausių verslo krypčių, todėl rūpinantis jos plėtra vis didesnis dėmesys telkiamas akvakultūrai, kuri užtikrina įvairių žuvų rūšių išteklių išsaugojimą. Lietuvai tapus ES nare, žuvininkystės plėtros galimybės tapo kur kas didesnės (tą lėmė rinkos laisvė, didelė prekybos erdvė). Žuvininkystei didelis dėmesys buvo telkiamas 2007-2013 m. žuvininkystės sektoriaus programoje. Taip pat svarbu paminėti, kad Lietuvoje įkurtas tarptautinio akvakultūros centro padalinys. Visa tai tik įrodo pakankamą akvakultūros reikšmę Lietuvos versle. Tad šiandien yra labai aktualu analizuoti, kokios yra akvakultūros vystymo galimybės, ekonominė nauda, kokios reikalingos veisimo sąlygos. Atsižvelgiant į tai, šiame darbe didelis dėmesys skiriamas analizuojamo žuvininkystės ūkio UAB „Vasaknos“ žuvų auginimo ypatumams, ekonominių duomenų analizei bei vandens fizinių ir cheminių savybių tyrimams bei jų analizei. Darbo tikslas: išanalizuoti lašišinių ir eršketinių žuvų auginimo ypatumus žuvininkystės ūkyje UAB „Vasaknos“ bei pateikti šio ūkio ekonominių rodiklių ir tvenkinių, saugyklų ir baseino vandens fizinių, cheminių savybių analizę. Darbo uždaviniai: 1) apibrėžti akvakultūros svarbą ir jos perspektyvas Lietuvos žuvininkystėje; 2) išnagrinėti lašišinių bei eršketinių žuvų rūšių ypatybes; 3) išanalizuoti lašišinių bei eršketinių žuvų auginimo ypatumus; 4) išanalizuoti 2010-2012 m. ekonominius rodiklius UAB „Vasaknos“; 5) ištirti UAB „Vasaknos“... [toliau žr. visą tekstą] / Fishery has rich traditions in Lithuania. It is one of the oldest branches of the business, so a growing attention for the aquaculture as for a tool for protecting various kinds of fishes’ resources is being paid at the moment. The possibilities of fishery development have increased significantly after Lithuania has become the member of EU – this is a result of market’s freedom and a bigger space of trading. A big attention for the development of the fishery has been paid in the Programme of the Fishery Sector for 2007-2013. Also it is important to notice that a Department of the International Centre of Aquaculture was established in Lithuania recently by showing the understanding of the importance of aquaculture in the Lithuania’s business field. In respect to this, it is very important today to analyse the possibilities of aquaculture development, its economical benefit as well as the conditions of fishes breeding. So in this Masters’ thesis a big attention is being paid for the peculiarities of fishes raising in the fishery farm UAB “Vasaknos” as well as for analysis of economical data of this farm and for the research of the physical and chemical characteristics of the farm’s ponds’ water. The aim of the thesis: to analyze the peculiarities of the salmon and sturgeon fishes raising in the fishery farm UAB “Vasaknos” as well as provide the analysis of the economical characteristics of this farm’s activity and physical and chemical characteristics of the farm’s ponds’... [to full text]

En biologie de la conservation, les pratiques de réintroduction consistent à élever des animaux en captivité et à les relâcher dans l’aire de répartition où l’espèce en question a décliné ou disparu, ceci dans le but de soutenir la population naturelle. Pour les poissons, l’élevage en pisciculture implique une sélection des individus au moment de la reproduction et un développement des jeunes stades dans un environnement contrôlé qui peuvent influencer fortement les attributs comportementaux,génétiques, morphologiques et physiologiques nécessaires pour répondre de manière adéquate aux conditions du milieu naturel. L’exposition de ces individus naïfs, particulièrement les jeunes stades, àla variabilité (environnements enrichis) pourrait limiter ces carences et améliorer la survie post lâcher.Dans ce cadre, des expérimentations sont nécessaires pour comprendre comment l’environnement d’élevage affecte les performances individuelles qui impacteront directement la fitness en milieu naturel et par conséquent l’efficacité des programmes de réintroduction avec un objectif de conservation. La dernière population d’esturgeon sauvage d’Europe de l’ouest est issue de la Gironde (Sud-Ouest France), il s’agit de l’esturgeon européen (Acipenser sturio). Cette espèce est classée en danger critique d’extinction et fait l’objet d’un programme de restauration européen décliné en plans d’actions nationaux en France et en Allemagne. Dans ce travail, cette espèce est utilisée comme modèle afin d’évaluer les effets des pratiques d’élevage sur la survie, la croissance et le comportement des jeunes de l’année en captivité puis leur comportement et leur survie post lâcher en milieu naturel. Des esturgeons nés en captivité, issus de 2 croisements, ont été élevés selon deux méthodes, l’élevage « traditionnel » (faible variabilité spatiale et temporelle) et l’élevage« enrichi » (augmentation de la variabilité spatiale et temporelle), jusqu’à ce qu’ils atteignent trois mois puis leurs performances ont été évaluées en conditions contrôlées. Les individus ont ensuite étaient relâchés en rivière et leurs déplacements individuels ont été suivis pendant 20 jours à l’aide d’une technologie de télémétrie acoustique après avoir évalué les effets du marquage sur les performances individuelles. Les résultats en conditions contrôlées mettent en évidence que dans un élevage enrichi les individus atteignent un poids et une taille supérieurs dès le premier mois de vie.L’analyse de la croissance révèle que les individus issus des deux croisements ont une croissance similaire en conditions enrichies mais celle-ci diffère dans un environnement traditionnel. L’analyse du comportement en milieu contrôlé indique que les individus élevés en conditions enrichies seraient plus lents à explorer un environnement inconnu mais plus nombreux que parmi les individus élevés de manière traditionnelle. Le suivi post-lâcher des jeunes stades de cette espèce et plus largement des espèces d’esturgeon a été réalisé pour la première fois dans le cadre de ce travail. La survie globale des poissons était de 69,3% (52.2−90.9%), la survie la plus faible concernant un croisement élevé de manière traditionnelle. [...] Ce travail milite pour que les pratiques de repeuplement et la recherche sur l’écologie des espèces travaillent en synergie afin de favoriser la mise en place d’une aquaculture adaptative qui soutienne la conservation des espèces. / Stocking for conservation purposes is the practice of raising animals in captivity and releasing the min to an area from which the species have either declined or disappeared, in an attempt to enhance the natural population. Fish reared in hatcheries are exposed to selective reproduction, and early life experiences in a safe setting can strongly influence the behavioral, genetic, morphological and physiological attributes necessary to respond adequately to natural conditions after stocking.Exposing naive individuals to variability during early stages −enriched environment− could reduce such deficiencies and improve fish survival after release. This approach needs to be studied tounderstand how it affects performance traits that will directly impact fish fitness in the wild and consequently, its effects on stocking programs efficiency for conservation. The last remaining wild sturgeon population in Western Europe, the European sturgeon (Acipenser sturio), is located in theGironde (Southwest France). This species is critically endangered and subject of a recovery plan with specific action plans in France and Germany. In this study, this species was used as a model to assess effects of rearing practices on survival, growth and behavioral performance of young-of-the-yearsturgeons before stocking and their behavior and survival in the wild after release. Captive-born sturgeons belonging to two crossings were reared under traditional (i.e. low spatial and temporal variability) and enriched (i.e. higher spatial and temporal variability) practices for 3 months and their performance was evaluated in laboratory. Then, the fish were released in the Dordogne River and their individual movements were tracked for 20 days using a acoustic telemetry system; after evaluating the tagging effects on fish performance. Results in the laboratory demonstrated that enriched environment resulted in bigger fish from the first month. Growth curve analysis revealed that enriched environment made both fish crossings grow in a similar manner. In contrast, crossings’growth differed in traditional rearing. Behaviorally, enriched-reared fish were slower to explore a new environment but more individuals engaged on doing so than traditional-reared fish. Post-release assessment on such small individuals was carried out for the first time for a sturgeon species. Fish over all survival was 69.3% (52.2−90.2%) where the lowest survival was found for one crossing reared under traditional conditions. After release, most movements (85.7%) occurred during the first three days after stocking and downstream direction. During the study, 82% of the fish were detected within 13.5km from the release site and no fish reached the saline estuary. Fish were mainly active during night hours, but traditional-reared fish were significantly more active during the day than enriched-reared fish during the first three days. Our findings advocate for the integration of enriched rearing practices within the juvenile production for release in order to boost the performances linked fitness. Stocking practices and life history research should work together to favor adaptive aquaculture approaches, which support species conservation / En conservación, la repoblación de especies es la práctica de criar animales en cautiverio y suposterior liberación en zonas donde la especie ha disminuido o desaparecido con la finalidad deaumentar la población natural. Los peces cultivados en piscifactorías están expuestos a la reproducción selectiva, y la experiencia temprana en ambientes seguros puede tener una fuerte influencia en los atributos genéticos, morfológicos, fisiológicos y de comportamiento, necesarios para responder adecuadamente en la naturaleza después de la liberación. La exposición de individuos sin experiencia previa a la variabilidad en el ambiente (ambientes enriquecidos) durante los estadios tempranos de su desarrollo puede reducir estas deficiencias y mejorar la sobrevivencia después de la liberación. Este tema necesita ser estudiado más a fondo para entender cómo el ambiente de cría afecta los atributos de rendimiento que influirán directamente en el “fitness” de los individuos una vez en la naturaleza y por consecuencia, en la eficiencia de los programas de repoblación para la conservación. El último relicto de esturión salvaje en el sudoeste de Europa, el esturión europeo (Acipenser sturio), está en peligro crítico de extinción, sujeto a un plan de recuperación y planes específicos de conservación en Francia y Alemania. En este estudio, esta especie fue usada como modelo para evaluar los efectos de las prácticas de cría en la sobrevivencia,crecimiento, y comportamiento en juveniles de menos de un año de edad antes de la liberación y, su comportamiento y sobrevivencia en la naturaleza después de la liberación. Para esto, esturiones de dos cruces diferentes fueron criados durante tres meses en cautiverio en ambientes tradicionales(baja variabilidad espacial y temporal) y ambientes enriquecidos (alta variabilidad espacial ytemporal) y evaluados en laboratorio. Posteriormente los peces fueron liberados en el río Dordoña y se rastrearon sus movimientos individualmente durante 20 días usando un sistema de telemetría; los efectos de este marcado se evaluaron previamente. Los resultados de laboratorio demuestran que la cría enriquecida produce peces de mayor tamaño desde el primer mes de crianza. Los análisis en las curvas de crecimiento revelaron que la cría enriquecida hizo que los peces de ambos cruces crecieran de manera similar. Por el contrario, el crecimiento fue diferente bajo la cría tradicional. Con respecto al comportamiento, los peces de cría enriquecida tardaron más en empezar a explorar un ambiente nuevo pero más individuos se involucraron en esta actividad que los peces de cría tradicional. En la naturaleza, es la primera vez que se monitorea esturiones de tan poca edad. La sobrevivencia global fue del 69.3% (52.2−90.9%) donde uno de los cruces criado tradicionalmente tuvo la tasa más baja.(...) Las prácticas de repoblación y la investigación de historia de vida deben trabajar en conjunto para favorecer los enfoques adaptativos de acuacultura que apoyen la conservación de especies.

I investigated Lake Sturgeon (Acipenser fulvescens) foraging and anti-predator behaviour. My goals were to understand: (1) The role of environmental change on foraging and anti-predator behaviour trade-offs. (2) The relative cost/benefit trade-off between escape behaviour and cover-seeking behaviour. (3) How development of several independent morphological traits affects anti-predator behaviours. I used simulated river mesocosms to study Lake Sturgeon behavioural ecology under controlled conditions. I found: (1) Foraging intensity was significantly higher during the night than the day as well as in turbid environments versus clear environments, indicating that decreased turbidity alone, may in part drive anti-predator behaviour and constrain foraging activity. (2) In high-risk clear-water environments, Lake Sturgeon responded to danger by evoking an escape response and seeking cover in rocky microhabitats. However, in low-risk turbid environments, Lake Sturgeon responded to danger by seeking cover in rocky microhabitats, but not fleeing to a significant degree. Cover-seeking behaviour may therefore be a relatively low-cost/high-benefit anti-predator strategy. (3) Strong evidence for trait co-dependence between escape responses and body size, where larger fish were able to elicit stronger escape responses. I also found that cover-seeking behaviour exhibited a complex multi-tiered relationship, representing a mixture of trait compensation and trait co-specialization that is dependent on specific combinations of morphological traits. These findings are important because they help us understand: (1) The degree to which anti-predator behaviour can be influenced by changing environmental conditions. (2) The relative cost/benefit trade-off between two common anti-predator behaviours. (3) How behaviour and morphology interact in species with a complex anti-predator phenotype.

Dentition is a key vertebrate innovation showing not only great morphological diversity, but also different maintenance or replacement of functional teeth. Most extant vertebrates replace their dentition through addition of new teeth from deeply invaginated epithelium, i.e. the successional dental lamina, due to presence of dental stem cells. However, in some early branching lineages of ray-finned fishes (Actinopterygii), new tooth germs arise from the adjacent superficial epithelium without the presence of the successional dental lamina. Whether the two types of dental development in vertebrates are equivalent and whether comparable dental stem cells play role in tooth replacement is currently not satisfactorily evaluated. This Master thesis aims at describing the development of palatal and pharyngeal dentition of a member of an early branching lineage of ray-finned fishes, the sterlet sturgeon (Acipenser ruthenus). The sterlet dentition is fairly dynamic. The teeth are replaced without the successional dental lamina, however, this replacement shows characteristics similar to those described in vertebrates with the successional dental lamina. A marker of dental stem/progenitor cells, Sox2, is localized in the outer dental epithelium of the predecessor tooth in the vicinity of the adjacent taste...

The role of fish in the Native American economy of the lower Columbia River has never been considered in detail. My study focused on the Columbia River from its mouth to the Cascades and the Willamette River from its confluence with the Columbia to Willamette Falls. For this study I asked: How was salmon used? What other fish were important? Where and how were these fish taken and used? To address these questions, I evaluated historical documents, including explorer's accounts and the administrative records of fur companies dating from the late 1700's through the 1850's. I used fishery data, physical descriptions, migratory and spawning habits, and foraging patterns to identify fish in historic accounts. I annotated historic information and provided a synthesis of the historic fisheries. White sturgeon (Acipenser transmontanus), eulachon (Thaleichthys pacificus) and chinook salmon (Oncorhynchus tshawytscha) dominated the trade. Chum (O.keta) and lamprey (Lampetra sp.) were available, although not traded in large numbers. White sturgeon, eulachon, fall chinook, chum and lamprey were smoke cured. Steel head (0. mykiss) , coho (O.kisutch), perch (Embiotocidae), and resident trout were traded in small numbers indicating that other fish were part of the economy. Sockeye. salmon (O.nerka) was not traded. f "~{.' Indians captured white sturgeon with: multiple hooks on set-lines and funnel nets to take white sturgeon during the winter; scoop nets and the eulachon rake took eulachon; spring and summer chinook were taken with hoop nets and platforms in the Cascades rapids and at Willamette Falls; gaffs were used to take chinook and sturgeon during the summer in Baker Bay; and hoop nets took fall chinook in streams. Seine nets were noted but not were not discussed except for the chinook fishery of Baker Bay. Historic information on fishes used and methods of capture contrasts with the archaeological record of the Portland Basin. Resident freshwater fish, minnows (Cyprinidae) and suckers (Catostomus sp.), are abundant in the archaeological faunal record, but are rarely mentioned in historic accounts. Artifacts such as net weights are common in archaeological contexts in contrast with the limited discussions in the historic record. Possible explanations for these discrepancies are reviewed.

In 1971, Isaac Asimov observed in humanity, a science-important society. For this he credited the man who had been his editor in the 1940s during the period known as the golden age of American science fiction, John W. Campbell, Jr. Campbell was editor of Astounding Science-Fiction, the magazine that launched both Asimov's career and the golden age, from 1938 until his death in 1971. Campbell and his authors set the foundation for the modern sci-fi, cementing genre distinction by the application of plausible technological speculation. Campbell assumed the science-important society that Asimov found thirty years later, attributing sci-fi ascendance during the golden age a particular compatibility with that cultural context. On another level, sci-fi's compatibility with "science-important" tendencies during the first half of the twentieth-century betrayed a deeper agreement with the social structures that fueled those tendencies and reflected an explication of modernity on capitalist terms. Tethered to an imperative of plausibly extrapolated technology within an American context, sci-fi authors retained the social underpinnings of that context. In this thesis, I perform a textual analysis of stories published in Astounding during the 1940s, following the sci-fi as it grew into a mainstream cultural product. In this, I prioritize not the intentions of authors to advance explicit themes or speculations. Rather, I allow the authors' direction of reader sympathy to suggest the way that favored characterizations advanced ideological bias. Sci-fi authors supported a route to success via individualistic, competitive, and private enterprise. They supported an American capitalistic conveyance of modernity. / Master of Arts

Abstract The Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus, Mitchell) is an anadromous species that spawns in tidal freshwater rivers from Canada to Florida. Overfishing, river sedimentation and alteration of the river bottom have decreased Atlantic Sturgeon populations, and NOAA lists the species as endangered. Ecologists sometimes find it difficult to locate individuals of a species that is rare, endangered or invasive. The need for methods less invasive that can create more resolution of cryptic species presence is necessary. Environmental DNA (eDNA) is a non-invasive means of detecting rare, endangered, or invasive species by isolating nuclear or mitochondrial DNA (mtDNA) from the water column. We evaluated the potential of eDNA to document the presence of Atlantic Sturgeon in the James River, Virginia. Genetic primers targeted the mitochondrial Cytochrome Oxydase I gene, and a restriction enzyme assay (DraIII) was developed. Positive control mesocosm and James River samples revealed a nonspecific sequence—mostly bacteria commonly seen in environmental waters. Methods more stringent to a single species was necessary. Novel qPCR primers were derived from a second region of Cytochrome Oxydase II, and subject to quantitative PCR. This technique correctly identified Atlantic Sturgeon DNA and differentiated among other fish taxa commonly occurring in the lower James River, Virginia. Quantitative PCR had a biomass detection limit of 32.3 ug/L and subsequent analysis of catchment of Atlantic Sturgeon from the Lower James River, Virginia from the fall of 2013 provided estimates of 264.2 ug/L Atlantic Sturgeon biomass. Quantitative PCR sensitivity analysis and incorporation of studies of the hydrology of the James River should be done to further define habitat utilization by local Atlantic Sturgeon populations. IACUC: AD20127