Thesis (Ph.D.)--University of Tasmania, 2000. / Library has additional copy on CD-ROM. Includes bibliographical references.

No description available.

Microplankton at five sites off South Georgia in January to February 1991 was dominated by a range of diatoms. The haptophyte Phaeocystis was present in three of the five sites but in low abundance only. Diatoms dominated at a more southerly site near the Antarctic Peninsula in March, whereas dinoflagellates dominated at a site near Deception Island. Multivariate analysis allowed the seven sites to be distinguished on the basis of microplankton species composition. Analysis of thirteen lipid classes present in total lipid extracted from the microplankton also demonstrated substantial differences from site to site. Multivariate analysis showed a different pattern of variation from the species ordination, with the South Georgia sites forming a distinct cluster. Outlier sites identified in the species and lipid ordinations confirmed the association between some taxonomic groups and lipid 'fingerprints'. Fatty acids extracted from total lipid in microplankton at five sites around South Georgia and two sites near the Antarctic Peninsula ranged from 37 to 195 J.Lg1-1, with a ratio of fatty acids in polar lipid: neutral lipid ranging from 4: 1 to 1:2. A further eleven particulate samples analysed from sites around the Antarctic Peninsula had slightly lower fatty acid content with a mean of 50 J.Lg1-1. Fatty acids in polar lipid were rich in (n-3) polyunsaturated fatty acids, chiefly 20:5(n-3). However, 22:6(n-3) could be as abundant as 20:5(n-3) in polar lipid from microplankton less than 20 J.1m, and also in dinoflagellate-rich microplankton. Neutral lipid was dominated by 16:0, 16:1(n-7) and 18:1(n-9) fatty acids and contained only low levels of (n-3) polyunsaturated fatty acids. The data reveal the high nutritional quality of microplankton lipids in the Southern Ocean for filter feeding animals, including krill. Samples of krill from eight sites around South Georgia consisted predominantly of immature animals, and females were entirely absent from samples from two of the eight sites studied. Animal wet mass varied from 0.16-1.72 g (median values of 0.47, 1.15 and 1.46 g for immatures, males and females respectively). Lipid amounts varied from 5-147 mg per animal (median values of 17.8, 21.0 and 73.3 mg for immatures, males and females respectively). Triacylglycerol (TAG) and phosphatidylcholine were the two most abundant lipid classes in all animals. Multivariate analysis of lipid composition indicated significant overlap between sex-maturity classes, although female krill tended to be distinguished from males by higher proportions of TAG and lower proportions of phosphatidylserine plus phosphatidylinositol. Reproductive investment is implicated in the overall variability in lipid content and composition, with females containing high lipid levels as reserves for egg production, whilst males showed apparent lipid deficits resulting from short-term mobilisation of storage material for spermatophore production and attachment. Significant and systematic site-to-site variability in lipid content and composition were evident in the samples and this could not be explained by the sex ratio or animal size. Such variability might have arisen from local patterns of krill distribution but could not be ascribed simply to temporal changes in lipid during the study. Immature Antarctic krill (length 40-45 mm) maintained in an aquarium for up to nine months were fed dense suspensions of cultures of two algal taxa, the haptophyte /sochrysis and the diatom Thalassiosira. Following acclimation to the experimental feeding regime, the animals were transferred to identical containers holding cultures of the same alga already labelled with [14C]bicarbonate. Faecal pellets collected after transfer showed detectable radioactivity after 30 minutes for /sochrysis and 55 minutes for Thalassiosira, providing an estimation of gut throughput time. With both algal cultures, radioactivity in faecal pellets increased over the 4-5 hour collection period. However, whilst faecal pellets derived from Isochrysis showed a rapid initial increase followed by an approach to a plateau value, the radioactivity in Thalassiosira-derived pellets increased steadily. A first-order kinetic model fitted to these data showed a more rapid turnover time for Isochrysis (k = 47 min) than for Thaiassiosira (k = 256 min). The assimilation efficiency based on the ratio of ingested radiolabelled lipid to that egested in faeces was 86% for /sochrysis and 63% for Thalassiosira, whereas corresponding efficiencies calculated from mass lipid budgets were 75% for /sochrysis and 77% for Thalassiosira. Analysis of fatty acid content and composition of total lipid from algae, krill and faecal pellets established that all dietary fatty acids were very efficiently ssimilated although there was a relatively preferential excretion of saturated fatty acids. All the assimilated fatty acids were extensively catabolised with the possible exceptions of saturated fatty acids and 18:4. Evidence was obtained for some biosynthesis of saturated fatty acids from non-lipid dietary precursors and for a limited conversion of 18:3 to 18:4 Collating the data presented in this thesis in a budget indicates that under suitable conditions, Euphausia superba is capable of acquiring the lipid necessary for growth and reproduction over time scales of only a few weeks and certainly within a single summer. Hence, krill appears to be an animal capable of high energy throughput and high reproductive output.

From a review of recent developments in the harvesting and processing of krill, an analysis is made of the market potential for the main products of a krill fishery, namely whole krill, tail meats, mince (particularly surimi) and meal. A techno-economic analysis of various catching - processing - product systems is made, in terms of costs and prices applicable in Western countries in 1977. The study finds that in practice the rapid spoilage rate of- krill after capture effectively determines that it should be processed on board freezer or factory trawlers. However, unless krill is marketed essentially as a crustacean product (even though in minced form) it is most unlikely to generate sufficient revenue to justify the high costs of its exploitation. Consideration is also given to the management issues raised by the exploitation of Antarctic krill in the context of the Southern Ocean. It is concluded that the quantities of krill likely to be taken by Western countries in the foreseeable future will be comparatively low. However. should the Soviets continue to expand their activities then even comparatively modest catch levels (of the order of a few million tonnes per year) could have a serious effect on Southern Ocean stocks, if not on krill, then on other species dependent upon this resource.

La temperatura es uno de los factores ambientales más importantes para la vida, siendo los ambientes fríos los que presentan la mayor distribución en la biosfera. Diferentes organismos han desarrollado diversas estrategias de tolerancia y adaptación al frío, entre ellas la síntesis de enzimas adaptadas/activas a bajas temperaturas. Estas enzimas especializadas se caracterizan por una alta eficiencia catalítica, temperaturas óptimas desplazadas a bajas temperaturas y termolabilidad a temperaturas moderadas. La disponibilidad del krill antártico, pequeño crustáceo explotado con fines comerciales, ha permitido el estudio de sus actividades enzimáticas. En el Centro de Ingeniería Bioquímica y Biotecnología los estudios se han centrado principalmente en la actividad proteasa y lipasa. Las enzimas lipolíticas están involucradas en le metabolismo lipídico, siendo las lipasas responsables de la hidrólisis y síntesis de triacilgliceroles. Basados en estos antecedentes se propone la siguiente hipótesis de trabajo: “el krill antártico Eupausia superba Dana posee enzimas lipolíticas adaptadas al frío, capaces de actuar in vitro a bajas temperaturas”, para el abordaje de esta hipótesis se desarrollaron tres objetivos específicos: (i) separación y obtención de enzimas lipolíticas de krill antártico, (ii) determinación de las características bioquímicas y fisicoquímicas de las enzimas lipolíticas purificadas y (iii) secuenciación y análisis de las secuencias de las enzimas lipolíticas de krill antártico. Se examinaron las condiciones para la obtención de un adecuado extracto enzimático, el procedimiento de autólisis a 40ºC durante 24 h o la homogenización a 8.300 rpm durante 1-2 min a 4ºC, permitió la obtención de un extracto con alta actividad lipasa específica. Se trabajó con dos enzimas lipolíticas de krill antártico, KL1 y KL2. La enzima lipolítica purificad KL1 presentó una masa molecular de 50 kDa y pI de 6,6 con una actividad sobre p-nitrofenilpalmitato (C16) de 2,9*103 U/mg a 20ºC y pH 8, presentó una temperatura óptima de 40ºC y pH óptimo de 9.KL1 exhibió un comportamiento inusual a temperaturas moderadas, sin embargo, a 10ºC retuvo el 23% de su actividad máxima, Se determinó una energía de activación de 24,7 kcal/mol (25-40ºC). Adicionalmente se caracterizó la enzima lipolítica KL2 previamente purificada que presentó una temperatura óptima a 37ºC y pH óptimo de 8, retuvo el 46% de su actividad máxima a 10ºC, Se determinó una energía de activación de 4,9 kcal/mol (10-37ºC). Las características de KL1 indiacarían que corresponde a una enzima mesofílica, en cambio, KL2 presentaría las propiedades de adaptación al frío (baja energía de activación y actividad a bajas temperaturas). El análisis de las secuencias de lipasas eucariontes realizado para el diseño de partidores para la identificación y ampliación PCR de genes de lipasa de krill antártico indicó que las lipasas presentan una baja similitud entre sus secuencias aminoácidos conservados contiguos y la peque ña longitud de las zonas conservadas, El análisis de las secuencias amplificadas por PCR no indicó similitud con lipasas. De igual modo el análisis de la secuencia parcial de KL2 tampoco mostró similitud significativa con lipasas, La ausencia de similitud probablemente se debería a las características antes señaladas de las lipasas, como también la posibilidad que correspondan a nuevas lipasas.

Der Antarktische Krill (Euphausia superba) ist eine Schlüsselart des Ökosystems des Südozeans und möglicherwese die biomassereichste Art der Erde. Klimawandelbedingte Lebensraumänderungen, die Expansion der kommerziellen Krillfischerei, sowie sich erholende Bartenwalpopulationen setzen Krillpopulationen jedoch zunehmend unter Druck. Daher besteht ein großer Bedarf, die Auswirkungen dieser verschiedener Stressoren auf Krillpopulationen zu verstehen und vorherzusagen. Dabei helfen Simulationsmodelle, die das Wachstum und die Entwicklung des Krills vorhersagen. Modelle sind vielseitige Instrumente, mit denen sich die Auswirkungen verschiedener Stressoren auf Krill in unterschiedlichen Szenarien bewerten lässt, was sie für Management- und Projektionsstudien besonders nützlich macht. In dieser Arbeit untersuchen wir Möglichkeiten die Robustheit von Modellen zu verbessern, die das Wachstum von Krillindividuen unter verschiedenen Umweltbedingungen vorhersagen. Zunächst haben wir ein bestehendes Wachstumsmodell erweitert, indem wir es um realistischere physiologische Prozesse ergänzt haben, was zu verbesserten Wachstumsvorhersagen führte. Anschließend haben wir in der Vergangenheit publizierte Wachstumsmodelle verglichen, um zu untersuchen, ob die Mechanismen des Krillwachstums verallgemeinerbar sind, da die Modelle für verschiedene Regionen entwickelt und mit unterschiedlichen Daten kalibriert wurden, regelmäßig aber außerhalb dieser Regionen verwendet werden. Diese Information ist wichtig für künftige Simulationsstudien, da eine regionale Spezifität die Modelle in ihrer großskaligen Anwendbarkeit limitieren würde. Die Wachstumsvorhersagen der verschiedenen Modellen bei identischen Inputdaten zeigte dabei, dass die Mechanismen und Wachstumsvorhersagen zwischen den Modellen erheblich variieren. Durch die Identifizierung der Ursachen dieser Modellspezifität, konnten wir das allgemeine Verständnis der Krill-Wachstumsmechanismen verbessern und zu der Entwicklung robusterer Modellen beitragen. Individuenbasierte Modelle ermöglichen die Einbindung vieler Prozesse, wie z. B. Verhalten, was diese Art von Modellen besonders attraktiv macht. Unser mechanistisches Verständnis des Verhaltens von Krill ist jedoch noch begrenzt, und wir haben versucht, dies durch die Analyse eines achtmonatigen Datensatzes über das vertikale Migrationsverhalten des Krills zu verbessern. Die Analysen zeigten, dass das vertikale Migrationsverhalten von Krillschwärmen sehr flexibel ist und wahrscheinlich von mehreren Faktoren wie dem Stadium, der Jahreszeit, den Nahrungsbedingungen und der Anwesenheit von Krillprädatoren bestimmt wird. Diese Studie dient als Grundlage für die Entwicklung von Modellkomponenten, die es erlauben das Krillverhalten in individualbasierte Modelle zu integrieren. Anschließend haben wir das vorhandene Wissen über das Krillverhalten in einem Reviewartikel zusammengefasst und dabei die möglichen Auswirkungen des Klimawandels auf Krillverteilung und das Schwarmverhalten analysiert. Zuletzt haben wir einen Systematic Literature Review durchgeführt, um eine Übersicht von Daten zu erstellen, die für die Modellentwicklung und -parametrisierung genutzt werden können. Auf diese Weise konnten wir Aspekte der Krillökologie identifizieren, für die aktuell besonders wenige Daten existieren, was wertvoll für zukünftige empirische Forschung sein wird. Da die Schließung dieser Datenlücken Zeit brauchen wird, diskutieren wir zudem auch Möglichkeiten zur Modellierung des Krillwachstums trotz bestehender Unsicherheiten. Mit dieser Arbeit leisten wir einen Beitrag zur Entwicklung realistischerer und robusterer individuenbasierter Krill-Wachstumsmodelle.:1. Introduction 2. Article I - The impact of seasonal regulation of metabolism on the life history of Antarctic krill (Euphausia superba) 3. Article II - An intercomparison of models predicting growth of Antarctic krill (Euphausia superba): the importance of recognizing model specificity 4. Article III - An open and lightweight method to analyze the vertical distribution of pelagic organisms using echogram screenshots 5. Article IV - Plasticity and seasonality of the vertical migratory behaviour of Antarctic krill using acoustic data from fishing vessels 6. Article V - Impacts of climate change on krill behaviour and population dynamics 7. Article VI - Mapping the data landscape for developing and parameterizing Antarctic krill models 8. Supervised Research Projects 9. Discussion 10. Literature cited in Introduction and Discussion 11. Appendices

A necessidade da criação de produtos inovadores com características funcionais está relacionada com a demanda de consumidores que priorizam o bem-estar vinculado a uma alimentação saudável e equilibrado. Nesse sentido, o objetivo deste estudo foi avaliar os efeitos da adição de succinil quitosana (SQ) como um substituto da fração lipídica e agente emulsificante sobre a qualidade de bolos. Para tanto, no capítulo 1 foi realizado um levantamento conciso da literatura para a compreensão dos temas abordados. No capítulo 2, o estudo da SQ se baseou na sua obtenção e caracterização para aplicaçãoem bolos. A análise de infravermelho e difração de raio X validaram as reações de desacetilação e succinilação, sendo que os estudos térmicos demonstraram estabilidade térmica (acima de 300 °C) viabilizando a utilização da SQ em produtos de panificação. A aplicação da suspensão de SQ (2,0 g/100 g) em massas de bolos com níveis reduzidos de gordura (0 % (controle), 25 %, 50 %, 75 % e 100 % (ausência total de gordura)) com ajustes na quantidade de água, para adaptação das consistências das massas, resultou em massas de bolos com parâmetros de viscosidade semelhantes. A redução de gordura até um nível de 50 % e presença de SQ contribuiu para o aumento da área 2D (de 13, 83 para 19,05 mm2) e razão largura/altura, além da umidade e atividade de água. A SQ influenciou significativamente (p < 0,05) na vida de prateleira, visto que a taxa de endurecimento foi de 27,8 (N/dia) para os bolos controle, e em bolos com nível de 25 % apresentou o valor de 26,1 (N/dia) e 49,2 (N/dia) para àqueles com presença total de SQ. Os teores de lipídeos diminuíram significativamente (p < 0,05), embora o conteúdo total de minerais e proteínas tenham apresentado ligeiras variações. Em relação à análise sensorial, foram atribuídas aos bolos com redução de até 50 % de gordura notas entre 6 e 7, e àqueles com 75 % de redução, nota inferior para os atributos de textura, sabor e aspecto geral. Dos provadores, 35 % \"provavelmente comprariam\" os bolos com 50 % de gordura. Nesse sentido, a SQ pode ser considerada um potencial substituto de gordura em bolos, podendo-se reduzir à metade a quantidade deste ingrediente em sua formulação original, agregando qualidades tecnológicas, sensoriais e nutricionais a esses produtos. / The need to create innovative products with functional characteristics is related to the demand of consumers which prioritize the well-being combined to a healthy and balanced diet. In this sense, the objective of this study was to evaluate the effects of the addition of succinyl chitosan (SQ) as an emulsifying agent and lipid fraction substitute on the qualities of cakes. Therefore, in chapter 1 a concise survey of the literature was carried out to understand the themes covered. In chapter 2, the SQ study was based on its obtaining and characterization for application in cakes. Infrared analysis and X-ray diffraction validated the deacetylation and succinylation reactions, and the thermal studies demonstrated thermal stability (above 300 °C), allowing the use of SQ in bakery products. The application of SQ suspension (2.0 g / 100 g) with reduced levels of fat (0 % (control), 25 %, 50 %, 75 % and 100 %) adjusting the amount of water, to adapt the batter\'s consistencies, resulted in cakes with similar viscosity parameters. The reduction of fat up to 50 % and presence of SQ contributed to the increase of the 2D area (from 13,83 to 19,05 mm2) and width / height ratio, as well as moisture and water activity. SQ significantly influenced (p <0.05) shelf life, since the hardening rate was 27,8 (N / day) for control cakes, and in cakes with a 25% level the value was 26,1 (N / day) and 49.2 (N / day) for those with total presence of SQ. The lipid contents decreased significantly (p <0.05), although the total content of minerals and proteins showed slight variations. Regarding sensory analysis, scores between 6 and 7 were attributed to cakes with a fat reduction of up to 50%, and those with a 75% reduction were attributed a lower score, according to the attributes of texture, taste and overall appearance. From consumers, 35% \"I would probably purchase\" the cakes with 50% fat. In this sense, SQ may be considered a potential substitute for fat in cakes, and it can reduce the amount of this ingredient by half in its original formulation, adding technological, sensorial and nutritional qualities to these products.

A necessidade da criação de produtos inovadores com características funcionais está relacionada com a demanda de consumidores que priorizam o bem-estar vinculado a uma alimentação saudável e equilibrado. Nesse sentido, o objetivo deste estudo foi avaliar os efeitos da adição de succinil quitosana (SQ) como um substituto da fração lipídica e agente emulsificante sobre a qualidade de bolos. Para tanto, no capítulo 1 foi realizado um levantamento conciso da literatura para a compreensão dos temas abordados. No capítulo 2, o estudo da SQ se baseou na sua obtenção e caracterização para aplicaçãoem bolos. A análise de infravermelho e difração de raio X validaram as reações de desacetilação e succinilação, sendo que os estudos térmicos demonstraram estabilidade térmica (acima de 300 °C) viabilizando a utilização da SQ em produtos de panificação. A aplicação da suspensão de SQ (2,0 g/100 g) em massas de bolos com níveis reduzidos de gordura (0 % (controle), 25 %, 50 %, 75 % e 100 % (ausência total de gordura)) com ajustes na quantidade de água, para adaptação das consistências das massas, resultou em massas de bolos com parâmetros de viscosidade semelhantes. A redução de gordura até um nível de 50 % e presença de SQ contribuiu para o aumento da área 2D (de 13, 83 para 19,05 mm2) e razão largura/altura, além da umidade e atividade de água. A SQ influenciou significativamente (p < 0,05) na vida de prateleira, visto que a taxa de endurecimento foi de 27,8 (N/dia) para os bolos controle, e em bolos com nível de 25 % apresentou o valor de 26,1 (N/dia) e 49,2 (N/dia) para àqueles com presença total de SQ. Os teores de lipídeos diminuíram significativamente (p < 0,05), embora o conteúdo total de minerais e proteínas tenham apresentado ligeiras variações. Em relação à análise sensorial, foram atribuídas aos bolos com redução de até 50 % de gordura notas entre 6 e 7, e àqueles com 75 % de redução, nota inferior para os atributos de textura, sabor e aspecto geral. Dos provadores, 35 % \"provavelmente comprariam\" os bolos com 50 % de gordura. Nesse sentido, a SQ pode ser considerada um potencial substituto de gordura em bolos, podendo-se reduzir à metade a quantidade deste ingrediente em sua formulação original, agregando qualidades tecnológicas, sensoriais e nutricionais a esses produtos. / The need to create innovative products with functional characteristics is related to the demand of consumers which prioritize the well-being combined to a healthy and balanced diet. In this sense, the objective of this study was to evaluate the effects of the addition of succinyl chitosan (SQ) as an emulsifying agent and lipid fraction substitute on the qualities of cakes. Therefore, in chapter 1 a concise survey of the literature was carried out to understand the themes covered. In chapter 2, the SQ study was based on its obtaining and characterization for application in cakes. Infrared analysis and X-ray diffraction validated the deacetylation and succinylation reactions, and the thermal studies demonstrated thermal stability (above 300 °C), allowing the use of SQ in bakery products. The application of SQ suspension (2.0 g / 100 g) with reduced levels of fat (0 % (control), 25 %, 50 %, 75 % and 100 %) adjusting the amount of water, to adapt the batter\'s consistencies, resulted in cakes with similar viscosity parameters. The reduction of fat up to 50 % and presence of SQ contributed to the increase of the 2D area (from 13,83 to 19,05 mm2) and width / height ratio, as well as moisture and water activity. SQ significantly influenced (p <0.05) shelf life, since the hardening rate was 27,8 (N / day) for control cakes, and in cakes with a 25% level the value was 26,1 (N / day) and 49.2 (N / day) for those with total presence of SQ. The lipid contents decreased significantly (p <0.05), although the total content of minerals and proteins showed slight variations. Regarding sensory analysis, scores between 6 and 7 were attributed to cakes with a fat reduction of up to 50%, and those with a 75% reduction were attributed a lower score, according to the attributes of texture, taste and overall appearance. From consumers, 35% \"I would probably purchase\" the cakes with 50% fat. In this sense, SQ may be considered a potential substitute for fat in cakes, and it can reduce the amount of this ingredient by half in its original formulation, adding technological, sensorial and nutritional qualities to these products.

Bifenilos policlorados (PCBs) e pesticidas organoclorados são compostos que não ocorrem naturalmente no ambiente e não são facilmente degradados química ou microbiologicamente. Seu estudo no ambiente é importante devido à sua persistência, toxicidade, lipossolubilidade e conseqüente biomagnificação. Por isso, representam a maioria dos poluentes orgânicos persistentes (POPs) considerados prioritários pela UNEP (United Nations Environmental Programme) e banidos ou restritos pela Convenção de Estocolmo, de maio de 2001. Tais poluentes podem ser facilmente emitidos para a atmosfera, atingindo áreas remotas como a Antártida, integrando um processo cíclico de contaminação conhecido como destilação global. No presente trabalho otimizou-se uma metodologia analítica capaz de detectá-los em ovos gorados de pingüins e indivíduos de krill coletados na Baía do Almirantado, Ilha Rei Jorge, Antártida. Tal metodologia foi avaliada e enquadrou-se em critérios internacionais de controle de qualidade. Os compostos mais presentes foram, de um modo geral, os PCBs, DDTs e o HCB e a ocorrência pareceu ser espécie-específica dentro do gênero Pygoscelis. Em todos os casos, o teor dos compostos não foi superior ao de aves árticas em nível trófico semelhante. A análise do krill permitiu estimar a biomagnificação dos compostos encontrados nos ovos, cuja única fonte de contaminação é a transferência fêmea-filhote. / Polychlorinated biphenyls (PCBs) and organochlorine pesticides are compounds that do not occur naturally in the environment and are not easily degraded by chemical or microbiological action. Their study in the environment is important due to persistence, toxicity, liposolubility and consequent biomagnification. For these reasons, they represent the majority of the persistent organic pollutants (POPs), considered to have priority by the UNEP (United Nations Environmental Programme) and banished and/or restricted by the Stockholm Convention of May, 2001. Such pollutants can be easily ejected into the atmosphere and reach areas as remote as Antarctica, integrating a cyclical contamination process known as ?global distillation?. In the present work an analytical methodology capable of detecting such compounds in unhatched penguin eggs and whole krill was optimized. The samples were collected in Admiralty Bay, King George Island, Antarctica. This methodology was evaluated and fitted international quality control criteria. The compounds found in higher levels were, in most of the samples, the PCBs, DDTs and HCB and the occurrence seemed to be species-specific for the Pygoscelis genus. In all of the cases, the levels found were not higher than the ones in arctic birds in a similar trophic level.The krill samples analysis made it possible to estimate the biomagnification of the compounds found in eggs, whose only source of contamination is the female-offspring transfer.

Submitted by Maike Costa (maiksebas@gmail.com) on 2017-01-30T14:52:04Z No. of bitstreams: 1 arquivo total.pdf: 977684 bytes, checksum: 2c0212ba73478698d80000576996a9f2 (MD5) / Made available in DSpace on 2017-01-30T14:52:04Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 977684 bytes, checksum: 2c0212ba73478698d80000576996a9f2 (MD5) Previous issue date: 2016-04-04 / Epilepsy is a neurological disease characterized by long duration disorders, where the most severe episode of this disorder is associated with seizure attacks. Science has been seeking new drugs, as well as unconventional treatments to provide quality of life for individuals affected by this disease. There is scientific evidence of an association between the fatty acid content of the diet and specific changes in neurotransmission system, especially polyunsaturated fatty acids, which are able to alter neuronal excitability, act as neuroprotective, in addition to possess anticonvulsant. This study aimed to investigate the possible anticonvulsant effects of krill oil (rich in polyunsaturated fatty acids) in the central nervous system of mice, evaluating even if it interferes with locomotor and / or muscle relaxation activity, and it has effects sedatives common to anticonvulsant drugs. We used 100 male Swiss mice were divided into control group (CG) received distilled water and krill Group (GK), which received the krill oil, both by gavage and the amount administered 1ml/100g of animal weight / day, for 30 days. Behavioral changes were analyzed on the 31st day through convulsive experiments (pilocarpine, electroshock and pentylenetetrazol), anxiolytics experiments (activity monitor, open, rota-rod and the elevated plus-maze). In the electroshock test the group submitted to supplementation with krill oil presented a shorter seizure when compared to the control group. In pentylenetetrazol test (PTZ) GK obtained a higher latency to onset of first seizure in addition to the reduction in tonic seizures and tonic-clonic, when compared to the CG. In the apparatus of the open field, it was observed an increase in immobility time, reduction in input frequency in the central quarters of the krill group, plus a reduction in peripheral ambulation compared to the control group. In Activity Monitor test, animals in the supplemented group traveled a shorter distance, less uptime and lower speed when compared to the control group. The results of the entry number in both the open arms and in the closed arms of the maze as well as the time spent in the open arms was not statistically significant, it was applied to pilocarpine and the test route rod. On krill oil the above is a possible candidate for the adjunctive treatment of seizures. / A epilepsia é uma doença caracterizada por transtornos neurológicos de longa duração, onde o episódio mais grave dessa patologia está associado a crises de convulsão. A ciência vem buscando novos fármacos, assim como tratamentos não convencionais para fornecer qualidade de vida aos indivíduos acometidos por essa doença. Há evidências científicas de uma associação entre o conteúdo de ácidos graxos da dieta e mudanças específicas no sistema de neurotransmissão, com destaque para os ácidos graxos poliinsaturados, que são capazes de alterar a excitabilidade neuronal, agirem como neuroprotetores, além de possuirem ação anticonvulsivante. O presente estudo teve como objetivo investigar os possíveis efeitos anticonvulsivantes do óleo de krill (rico em ácidos graxos poliinsaturados) no sistema nervoso central de camundongos, avaliando ainda se o mesmo interfere na atividade locomotora e/ou no relaxamento muscular, bem como se possui efeitos sedativos comuns a fármacos anticonvulsivantes. Foram utilizados 100 camundongos Swiss machos, divididos em Grupo Controle (GC) que recebeu água destilada, e Grupo Krill (GK), que recebeu o óleo de krill, ambos por gavagem sendo a quantidade administrada 1mL/100g de peso do animal/dia, durante 30 dias. As alterações comportamentais foram analisadas no 31°dia por meio dos experimentos convulsivantes (pilocarpina, eletro-choque e pentilenotetrazol), experimentos ansiolíticos (monitor de atividade, campo aberto, rota-rod e o labirinto em cruz elevado). No teste do eletrochoque o grupo submetido à suplementação com óleo de krill apresentou um menor tempo de convulsão quando comparado ao grupo controle. No teste pentilenotetrazol (PTZ) o GK obteve uma maior latência para o aparecimento da primeira convulsão, além da diminuição das convulsões tônicas e tônico-clônicas,quando comparado ao GC. No aparelho do campo aberto, foi observado um aumento do tempo de imobilidade, redução na frequência de entrada nos quadrantes centrais do grupo krill, além de uma redução na ambulação periférica quando comparado ao grupo controle. No teste do monitor de atividades, os animais do grupo suplementado percorreram uma menor distância, com menor tempo de atividade e uma menor velocidade, quando comparado ao grupo controle. A análise dos resultados do número de entrada, tanto nos braços abertos quanto nos braços fechados do labirinto, bem como o tempo de permanência nos braços abertos, não demonstrou significância estatística, o mesmo foi aplicado para o teste de pilocarpina e o rota rod. Diante do exposto o óleo de krill é um possível candidato ao tratamento coadjuvante da convulsão.