Notre étude s’inscrit dans un processus de recherche de nouveaux composés d’origine naturelle à activités biologiques avérées à partir de macroalgues brunes, avec d’éventuelles perspectives d’exploitation industrielle. Ainsi, dans un premier volet nous avons testé des méthodologies innovantes en matière d‘extraction en utilisant trois espèces d’algues brunes comme modèles. Nous avons optimisé le protocole d’extraction solide/liquide en estimant divers paramètres cruciaux qui influent sur le rendement d’extraction et sur les activités antiradicalaires des composés extraits. Soucieux de trouver une méthodologie innovante d’extraction plus « verte » répondant aux normes européennes, nous avons donc testé des méthodes d’extraction utilisant des solvants dans leur état supercritique ou sous forme pressurisés. La comparaison avec le procédé d’extraction solide/liquide nous a permis de sélectionner l’extraction par fluides pressurisés (PLE) employée avec un mélange Ethanol-Eau pour l’extraction de composés antiradicalaires avec une haute efficacité. Dans une deuxième partie nous nous sommes intéressés aux variations quantitatives et qualitatives des principales macromolécules présentes chez l’espèce invasive Sargassum muticum en Europe. L’emploi de deux techniques analytiques, RMN HR-MAS et spectroscopie IR, nous a permis d’avoir une vue d’ensemble des compartiments susceptibles de subir des variations selon la position géographique d’une même espèce à large répartition. Cette étude nous a montré comment une espèce est capable de changer sa composition biochimique en fonction de son environnement et ainsi s’acclimater à des milieux assez différents. Ce travail a mis en évidence les effets de différents paramètres environnementaux sur les compartiments lipidique (analysés en GC), protéique ainsi que sur les quantités de carbohydrates et de pigments (analysés en HPLC). L’influence de ces paramètres sur la taille des individus de Sargassum muticum a également été discutée. La dernière partie de cette étude nous a permis de décrire les variations quantitatives et qualitatives des phlorotannins chez l’espèce invasive Sargassum muticum sur une grande échelle spatiale, le long d’un gradient latitudinal (Norvège-Portugal). Dans un premier temps cette variabilité a été appréhendée grâce à un suivi temporel et spatial des teneurs en phlorotannins. L’étude des variabilités intra-spécifiques et intra-individuelles nous a permis de mettre en évidence un effet du stade de développement et de la partie de l’algue considérée : les teneurs et activités des phlorotannins sont plus importantes dans les crampons et chez les individus matures. Après la recherche d’un protocole simple pour la semi-purification des composés phénoliques présent chez Sargassum muticum, nous avons pu mettre en évidence la présence de composés de type phlorethol au moyen de techniques de RMN à deux dimensions (2D). Ces fractions semi-purifiées possèdent des activités antiradicalaire et antibactérienne notoires. Enfin, l’utilisation de plusieurs techniques de séparation membranaires nous a permis d’estimer le poids moléculaire des différents composés présents dans le pool de composés phénoliques extrait. Enfin, suite aux constats effectués sur les populations, l’effet de l’intensité lumineuse et de la température de l’eau a pu être apprécié isolément : les radiations UVA et UVB boostent la production de CP alors qu’une augmentation de la température fait chuter la production de CP chez S. muticum. / Our study is part of the research process for new compounds of natural origin with biological activities and possible industrial perspectives. In a first part, we tested innovative extraction methodologies using three brown algae species as model. We optimized the solid/liquid extraction protocol by estimating diverse crucial parameters which influence the extraction yield and radical scavenging activities of extracts. In order to find an innovative and more "green" extraction methodology answering the European standards, we thus tested more recent extraction methods using solvents in their supercritical state or under pressure. The comparison with the solid/liquid process allowed us to select pressurized liquid extraction (PLE) using an ethanol-water mixture for the extraction of active compounds with a high efficiency, but also to select Sargassum muticum as an interesting model for further investigations. In a second part, we were interested in the quantitative and qualitative variations of the main macromolecules present in the invasive species S. muticum in Europe. The employment of two analytical techniques (NMR HR-MAS and IR spectroscopy), allowed us to have an overview of biochemical parts of the algae, which vary according to the geographical position of this wide spread species. This study showed how a species is able to modify its biochemical composition, and then to acclimate, according to the environment. We then focused on molecules, which showed important variations along the latitudinal range of S. muticum. This work highlighted the effects of environmental parameters on lipid (GC analysis) and protein compartments as well as on carbohydrates and pigments quantities (HPLC analysis). The influence of these parameters on the size of individuals was also discussed. The last part of this study allowed us to describe the quantitative and qualitative variations of phlorotannins in S. muticum on a large spatial scale, along a latitudinal gradient (Norway-Portugal). At first this variability was measured thanks to temporal and spatial follow-up of the phlorotannins contents. The study of intra-specific and intra-individual variabilities allowed us to highlight an effect of the development stage and of the seaweed part: phlorotannins contents and activities are more important in holdfast and in mature individuals. After the research of a simple protocol for the phenolic compounds semi-purification present in Sargassum muticum, we were able to highlight the presence of compounds of only phlorethol type in this species by means of 2D RMN techniques. These semi-purified fractions possess notorious radical scavenging and antibacterial activities. Finally, the use of several membrane separation techniques allowed us to consider the molecular weight of the various compounds present in the extracted pool of phenolic compounds. Finally, under controlled conditions, the effects of the light quality and the seawater temperature were tested: UV-A and UV-B radiations boost the production of CP while an increase of the temperature makes the phlorotannins production decreasing in S. muticum.

Trois modèles invasifs à large répartition en Europe, le long d'un gradient latitudinal Norvège-Portugal, ont été choisis : Sargassum muticum, Codium fragile et Gracilaria vermiculophylla. Cette thèse a pour objectif l'étude de la phénologie, de l'écophysiologie et du métabolome de ces macrophytes invasifs face à une variation de facteurs environnementaux 1) à une échelle locale, 2) à l'échelle du gradient latitudinal (en lien avec le changement climatique global) ainsi que l'étude 3) des voies de valorisation possibles des métabolites de stress par bio-inspiration. Le gradient latitudinal, se traduisant par un gradient thermique, permet de mimer le réchauffement climatique car les conséquences de ce changement climatique sur les espèces en milieu naturel ne sont généralement appréciables qu'à l'échelle de dizaines d'années. Les suivis de l'écologie, dumétabolome ainsi que des impacts potentiels de ces espèces à une échelle locale en France, a permis d'étudier le développement et le cycle de vie des espèces. En particulier, G. vermiculophylla se caractérise par une phénologie spécifique (avec la prépondérance de petits fragments végétatifs, <3cm) en Rade de Brest et par une tolérance accrue à l'envasement jusqu'à 12 cm de profondeur en acclimatant son métabolome tout en maintenant une physiologie dormante. Cette espèce ingénieur impacte en profondeur l'écosystème vaseux de la Rade. Le suivi le long du gradient latitudinal a permis d'illustrer la plasticité phénologique des espèces et notamment un potentiel invasif contrasté de C. fragile entre les différentes latitudes. Lors de marée basse de vives eaux, les espèces présentent une acclimatation de leur photo-physiologie en fonction de la latitude avec la mise en évidence d'une photoinhibition du PSll, lié au stress engendré par les conditions environnementales.Enfin, ce travail a illustré les propriétés multifonctionnelles d'extraits enrichis en composés phénoliques, présentant des activités antioxydantes mais également photoprotectrices ou ostéogéniques, soulignant l'émergence de voies de valorisation originales par bio-inspiration pour divers secteurs tels que la cosmétologie et les biomatériaux en santé humaine. / Three model species with a large distribution along European coasts, along a latitudinal gradient from Norway to Portugal was chosen: Sargassum muticum, Codium fragile and Gracilaria vermiculophylla. The aims of this PhD thesis were to study the phenology, ecophysiology and the metabolom of these non-native marine macrophytes and their ability to cope with a variation of environmental factors 1) at a population scale, 2) along the latitudinal gradient (in relation with the global climatic change) and to propose 3) bio-inspired molecules for industrial purposes. The latitudinal gradient corresponding to a thermic gradient, allows to imitate the global warming as climatic change ¡mpacts are most of the time only visible at decennial scale.Monitorings of ecology, metabolome and potential impacts of these macroalgae, at a population scale, allowed to study the development and life cycle of these models. In particular, G. vermiculophylla exhibited a specific phenology (with a majority of small vegetative fragments, <3cm) in the Bay of Brest and a highly tolerance to burial until 12 cm depth in the sediment by acclimatizing its metabolome together with the ability to maintain a dormancy physiology. This engineer species modifies deeply muddy shores of this Bay. Latitunal gradients's monitoring highlighted the phenological plasticity and a contrasted invasive potential of C.fragile between latitudes. During low spring tides, species exhibited an acclimation of their photophysiology between latitudes with photoinhibition process related to induce environmental stress. Furthermore, this work showed the multifunctional properties of polyphenols enriched extracts with antioxidant, photoprotective or osteogenic activities, highlighting the emergence of original bio-inspired pathways for cosmetic or biomaterial applications.

Master of Science / Department of Biology / Anthony Joern / Temperature and food quality vary across broad latitudinal gradients, greatly affecting performance by insect herbivores. The contribution of each varies latitudinally so that geographically distinct populations are challenged by differences in nutritional needs and energetic demands. While there has been extensive work studying diet selectivity and nutritional ecology of insect herbivores, few studies have focused on how insect herbivores adapt across such vast environmental gradients. The generalist-feeding grasshopper, Melanoplus femurrubrum (DeGreer), has a broad geographic range that extends across much of North America, making this species ideal for comparative investigations of intrinsic performance responses to extensive but predictable patterns of environmental variation. I compared responses by six populations collected from populations located from Texas to North Dakota (USA) using a common garden experimental design to investigate clinal responses in grasshopper performance. I examined responses in: (1) body size, (2) thermoregulation and adaptive coloration, (3) developmental and growth rates, (4) metabolic rates, (5) total consumption and rates, (6) diet ratio selection, and (7) digestive processing efficiencies across the latitudinal gradient. Grasshopper body size followed the Converse Bergmann’s Rule with decreasing body size as latitude increased. Temperature influenced all other responses, but responses to diet were not always significant or directional. Latitudinal trends for development and growth rates were observed but mass-specific metabolic rates were similar for all populations. Total consumption was body size dependent but independent of diet type. Mass-specific consumption varied but no single directional trend was detected. There was a shift in carbohydrate-biased diet preference at low latitude toward protein-biased diet ratios at higher latitudes, suggesting adaptations to different energetic demands by these populations. However, post-ingestive (digestive) efficiencies demonstrated variable responses with northern populations observing highest efficiencies for some indices but not all. Overall, this research documents phenotypic plasticity to environmental variability to some degree for digestive efficiencies, but ecotypic responses in body size and diet preference among M. femurrubrum populations were observed.

This study investigated the impact of three edaphic factors on the distribution of forest plants in Sweden. Based on 2657 plots with 22 common species, Canonical Correspondence Analysis (CCA) and Generalized-linear-model (GLM) were performed with pH measurements in the top layer of the soil, latitude and deciduous tree proportion as explanatory variables. Variation of the species occurrence could to a substantial degree be explained by pH, latitude and proportion of timber volume of deciduous tree species. Furthermore, the majority of species were affected by the studied environmental variables. Therefore, these factors have an important role in the ecological interactions in the forest. All species also showed broad pH-niches with many occurrences spread out within the species entire pH-range. Finally, the study relates to educational science through designing a meaningful excursion for secondary school when teaching ecology.

Orientador: Marco Antonio de Assis / Banca: Sergius Gandolfi / Banca: Natália Macedo Ivanauskas / Resumo: Este trabalho foi desenvolvido em um trecho de Floresta Ombrófila Densa Atlântica no Núcleo Picinguaba do Parque Estadual da Serra do Mar, litoral norte do Estado de São Paulo, município de Ubatuba-SP. A área de estudo corresponde a uma das parcelas amostrais (Parcela D) do Projeto Temático "Composição florística, estrutura e funcionamento da Floresta Ombrófila Densa dos Núcleos Picinguaba e Santa Virgínia do Parque Estadual da Serra do Mar" do Programa BIOTA-FAPESP. Nosso estudo foi estruturado em três capítulos. No Capítulo 1, objetivamos descrever a composição florística e a estrutura da comunidade arbórea em uma parcela de 1 ha; avaliar o padrão de distribuição espacial das espécies e; investigar a ocorrência de correlações entre a distribuição das espécies e as variáveis 'altitude média', 'desnível topográfico', 'cobertura rochosa', 'presença de água na superfície do solo', 'distância do rio' e 'luz no interior da parcela', através de uma CCA. No Capítulo 2, investigamos a distribuição da riqueza e da diversidade de espécies ao longo do perfil vertical, considerando os estratos adultos e regenerantes da comunidade, buscando responder em quais níveis de altura está presente o maior número de espécies arbóreas. No Capítulo 3, avaliamos a distribuição das espécies e os padrões de similaridade florística entre áreas de Floresta Ombrófila Densa das Terras Baixas e Submontana situadas ao longo de um gradiente latitudinal entre os Estados do Rio de Janeiro e Santa Catarina. Nossos resultados revelaram valores elevados de riqueza (161 spp) e diversidade (H' = 4,0) no hectare analisado. Observamos padrões de distribuição espacial aleatórios para a maioria das espécies na comunidade, onde apenas Euterpe edulis, Alsophila sternbergii e Coussarea meridionalis var. porophylla apresentaram padrão agregado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study was conducted in a stretch of Atlantic Rain Forest at Núcleo Picinguaba do Parque Estadual da Serra do Mar, northern coast of São Paulo State, municipality of Ubatuba-SP. The study area represents one of the sample plots (Plot D) of the Project "Composição florística, estrutura e funcionamento da Floresta Ombrófila Densa dos Núcleos Picinguaba e Santa Virginia do Parque Estadual da Serra do Mar" Programa BIOTA-FAPESP. Our study was structured in three chapters. In Chapter 1, we aimed to describe the floristic composition and tree structure in a plot of 1 ha; assess the pattern of spatial distribution of species and, to investigate the occurrence of correlations between species distribution and the variables 'average height', 'topographic gap', 'cover rock ', 'presence of water on soil surface', 'distance from the river' and 'light in the interior of the plot', through a CCA. In Chapter 2, we investigated species richness and diversity distribution along the vertical profile, involving both regenerating and adult strata, in order to answer which height levels show the greatest number of tree species. In Chapter 3, we assessed species distribution and the occurrence of patterns on floristic similarities between areas of Lowlands and Submontanes Atlantic Rain Forests areas along a latitudinal gradient between Rio de Janeiro and Santa Catarina states. Our results revealed high richness (161 spp) and diversity (H' = 4.0) values in the area examined. We observed random patterns on spatial distribution for most species in the community, where only Euterpe edulis, Alsophila sternbergii and Coussarea meridionalis var. porophylla showed clumped patterns. Significant correlations between species and environmental variables matrices were detected for axis 1 of CCA (p = 0.001). The regenerating stratum showed greater floristic richness than adult stratum and higher values... (Complete abstract click electronic access below) / Mestre

O camarão corrupto Callichirus seilacheri foi erigido por Bott (1955) através de uma breve e incompleta descrição carente da maioria das ilustrações sobre as principais estruturas corporais desta espécie. Callichirus seilacheri é considerada, atualmente, como o único representante do gênero Callichirus na costa do Pacífico Leste. Sua distribuição geográfica abrange um amplo gradiente latitudinal de aproximadamente 50º graus (~13º N - 37º S) desde a praia Los Blancos (localidade-tipo), El Salvador até Lenga na costa de Chile. O estado taxonômico da grande população de C. seilacheri tem sido questionado no passado em reiteradas oportunidades. Este questionamento tem relação com a falta de estudos taxonômicos associados com estas populações e com o fato que alguns antecedentes moleculares têm demonstrado que as populações de Callichirus da costa do Pacífico de Nicarágua e México são diferentes. Considerando estes antecedentes, o primero objetivo do presente estudo foi avaliar o estado taxonômico de C. seilacheri na costa do Pacífico Leste da América Central. Para isto, foi coletado material de C. seilacheri em diferentes localidades da costa do Pacifico de América Central, incluindo a localidade-tipo desta espécie na costa de El Salvador. Conforme as observações morfológicas do material coletado, os caracteres diagnósticos de C. seilacheri incluem entre outros aspectos: (i) pedúnculos oculares com uma alongada projeção pré-córneal, cujas pontas divergem lateralmente; (ii) segmentos terminais do pedúnculo antênular e antenal com as bases paralelas; e (iii) pereiópodo maior do primeiro par de pereiópodos dos machos adultos com o mero armado de um lóbulo retangular na região ventral anterior e ísquio curvado para baixo com um gancho na margem ventral. Uma das descobertas mais relevantes foi que todas as fêmeas de C. seilacheri têm ambos gonóporos masculino e feminino, o qual representa o primeiro registro de intersexualidade no gênero Callichirus. O segundo objetivo desta tese foi avaliar se a espécie da costa chilena Callichirus garthi (Retamal, 1975), considerada como uma sinonímia-junior de C. seilacheri da costa do Pacífico da América Central, é uma espécie válida. Para isto, comparou-se o material-tipo de C. garthi e outros lotes desta espécie coletados ao longo da costa de Chile (~18º e 37º S) com os espécimes de C. seilacheri coletados na localidade-tipo (Playa Los Blancos, El Salvador) e em outras localidades da América Central. A comparação morfológica revelou importantes diferenças morfológicas entre os tipos morfológicos identificados em ambas espécies. Entre as principais diferenças e possível mencionar que C. garthi possui as pontas dos pedúnculos oculares paralelas, enquanto que em C. seilacheri são divergentes formando um angulo de 60-70°. Os machos adultos de ambas espécies compartilham quelípodos desiguais na fase adulta, mas somente, C. seilacheri tem um gancho sobre a margem ventral do ísquio e um lóbulo meral retangular. A analise morfológica do material biológico coletado em ambas regiões permite concluir que os espécimes coletados ao longo da costa do Chile pertencem à C. garthi, enquanto que os exemplares coletados na costa do Pacífico da Costa Rica pertencem à espécie C. seilacheri. Conforme a essas informações, C. garthi é uma espécie válida. Portanto, sugere-se a separação da grande população de C. seilacheri em duas diferentes populações: (i) uma pertencente ao C. seilacheri a qual ocorre desde a costa do El Salvador ate Costa Rica (~19º N 08º N), (ii) outra pertencente ao C. garthi a qual ocorre entre os 18º S e 37º S da costa chilena. A hipótese do centro abundância (HCA) é baseada na suposição de que as retricções fisiológicas limitam o desenvolvimento das populações nas bordas do seu intervalo de distribuição. Com o intuito de testar a validez desta hipótese, espécimes da espécie modelo Callichirus garthi foram coletados em sete populações distribuídas ao longo da costa chilena. Em cada população foram avaliados a densidade junto com uma serie de atributos populacionais de C. garthi (e.g. tamanho máximo do corpo, razão sexual, etc). Os principais resultados revelaram que C. garthi foi significativamente menos abundante nas populações locais, perto do centro e aumentou para as bordas norte e sul da sua distribuição na costa do Chile. No extremo sul e norte da distribuição, a estrutura da população foi composta por indivíduos de todos os tamanhos, em contraste com às localidades do centro, onde os indivíduos estavam concentrados em uma faixa de tamanho mais estreita. Surpreendentemente, nas bordas (norte e sul), à razão entre os sexos foi estremamente equilibrada. A abundância local foi levemente correlacionada com a distância entre cada localidade e o rio mais próximo e foi fortemente correlacionada com a estrutura da população. Aparentemente, a proximidade de um rio oferece as condições ideais para que C. garthi forme populações densas e equilibradas, o qual seria um reflexo do sucesso a nível individual que esta espécie atinge em direção às bordas. O modelo de distribuição de abundância de C. garthi pode ser considerado como uma exceção nas populações naturais devido que na maioria dos estudos prévios nesta matéria o modelo usualmente reportado é o modelo normal de abundância para um dos extremos. As generalizações acerca do padrão reprodutivo dos invertebrados bentônicos costeiros propõem que as espécies tropicais tenham reprodução do tipo continua, como reflexo das baixas oscilações térmicas ao longo de todo o ano (hipótese de Orton). Com o propósito de testar esta suposição em um ambiente tropical da América, foram realizados durante um ano amostragens mensais em uma população de C. seilacheri da costa do Pacífico de Costa Rica (América Central). Os resultados revelaram que C. seilacheri tem uma marcada sazonalidade reprodutiva, a qual contradiz os padrões esperados em regiões tropicais. As fêmeas ovígeras estiveram presentes desde maio até novembro, o que está estatisticamente relacionado com a diminuição da salinidade durante a estação chuvosa. A temperatura não teve influência sobre a periodicidade reprodutiva. Aparentemente, à reprodução em C. seilacheri está fortemente relacionada com a variabilidade climática da costa do Pacífico na Costa Rica, sendo desencadeada por oscilações na salinidade. Uma comparação entre C. garthi da costa chilena e C. seilacheri da costa do Pacífico da América Central revelou importantes diferenças na produção de ovos. Callichirus seilacheri produz uma media de quatro menos ovos e menores que C. garthi da costa do Chile. A variabilidade nas características reprodutivas (produção e tamanho dos ovos) e de tamanho corporal dos indivíduos observada nestas duas espécies de camarões corruptos sugerem a imposição de importantes restrições fisiológicas dadas principalmente por a temperatura em ambas às regiões da América. Os aspectos examinados no presente estudo constituem novos antecedentes sobre a taxonômia, morfologia e ecología em um dos gêneros da família Callianassidae mais representativos nas praias de areia da América. Cada um destas informações pode ser considerado de especial relevância para a conservação das populações de C. garthi e C. seilacheri no Pacífico Leste. Especialmente, porque ambas espécies são frequentemente recolhidas como isca para a pesca comercial e esportiva em algumas pequenas vilas costeiras. / The ghost shrimp Callichirus seilacheri was erected by Bott (1955) through a brief and poorly illustrated description. This species is considered as the only one current representative of genus Callichirus along the eastern Pacific. Their distribution encompasses approximately 50 degree of latitude, from Los Blancos, El Salvador (13º N) to Lenga, Chile (37º S). The identity of the large population of C. seilacheri along the Pacific coast of Americas has been questioned by different researchers whom have indicated the existence of more than one species of Callichirus for the Pacific coast of Mexico and the Pacific coast of Costa Rica and Nicaragua. Considering this information, the first focus of this thesis was realize a redescription of C. seilacheri based on specimens collected in different localities from Central America, including the type-locality of this species. According to the observations, the diagnostic features of C. seilacheri include (i) the eyestalks with elongated precorneal projection with tips diverging laterally; (ii) terminal segments of antennular peduncle and antennal with the parallel base and (iii) adult male with larger cheliped with rough rectangular lobe over anterior ventral margin of merus, ischium curved downward with a hook on ventral margin. All females analyzed herein have both male and female gonopores, thus firstly recorded the presence of intersex within the genus Callichirus. The second objective of this thesis was test whether Callichirus garthi (Retamal, 1975) which is considered as a junior synonymy of C. seilacheri constitute a valid species for the eastern Pacific. For this, a full comparison between specimens of the genus Callichirus collected along the Pacific coast of Central America and Chilean coast, including the type-locality of C. seilacheri and C. garthi was realized. The comparison revealed important morphological differences between both species. For example, in C. garthi the tips of the eyestalk are parallel while diverge distally forming an about 60-70° angle in C. seilacheri. Adult males of both species share unequal chelipeds; however, only C. seilacheri has a hook on ventral margin of ischium and its merus is armed with a rectangular lobe over anterior ventral margin. Additional material collected along the Chilean coast and from different localities from the Pacific coast of Costa Rica allowed confirms the taxonomic status of both species in the Eastern Pacific. All specimens collected along the Chilean coast belong to C. garthi while those of Costa Rica fit to form of C. seilacheri from El Salvador. According to the results, C. garthi is a valid species. Therefore, it is postulated the separation of large population of C. seilacheri into two different populations: (i) one belonging to C. seilacheri which distributes from Mexico to Costa Rica (~19º 08º N), (ii) other assigned to C. garthi which encompasses, at least, between 18º S 37º S of the Chilean coast. The abundant-centre hypothesis (ACH) is based on the assumption that physiological constraints limit populations at the edges of their distributional range. In the third chapter is examined the applicability of the ACH in a marine system by testing whether physiological predictions are reflected in large-scale variations of life-history traits. In order to achieve this information, specimens of Callichirus garthi were collected in the intertidal zone at seven sampling sites. In each site we evaluated (i) local abundance, (ii) maximum body size, (iii) sex-ratio, (iv) length-size frequency distribution, and (v) size at maturity. The main outcomes revealed that C. garthi is a species of low occurrence which was present in seven of all visited beaches (N = 61). Callichirus garthi was clearly less abundant within local populations near the centre and increased towards the northern and southern edges of its distribution. This pattern of abundance was significantly fitted by the abundant edge model. At the southern end and northern of the distribution, population structure was composed by individuals of all sizes in contrast with localities from the centre where individuals were concentrated in a narrow size range. Surprisingly at the edges (north and south), the sex ratio was extremely balanced. Physical variables (SST, grain size) had not influences on variation of life-history traits; however, the local abundance was slightly correlated with the distance between each locality and the closest river and was strongly correlated with population structure. Overall, the observed pattern was intimately linked with input of nutrients from the closest rivers. The findings allow separate the great population of C. garthi along the Chilean coast in two kinds: (A) stable populations (at the border of distribution), and (B) unstable populations (at the centre of distribution). In both cases, the population demography is controlled by dense-dependent factors. The results underline the importance of incorporating ecological, physiological and life-history studies in future tests of the ACH. Generalizations about breeding patterns of near-shore benthic marine invertebrates have proposed that tropical species have continuous reproduction as a reflection of constant temperature throughout the year (Ortons hypothesis). Based on this assumption, it was analysed the reproductive periodicity and egg production in the intertidal ghost shrimp Callichirus seilacheri from the Central Pacific coast of Costa Rica. In order to obtain such information, a total of 449 individuals were collected monthly from December 2011 to November 2012. The results showed that females with ovaries filled with mature oocytes were present throughout the whole year. However, the presence of ovigerous females was restricted to the period between May and November which fits to a seasonal breeding cycle. Apparition of egg-bearing females was statistically correlated with the decrease of salinity detected during rainy season, but not with temperature. Compared to C. garthi from temperate waters, C. seilacheri produced on the average four times less eggs and smaller. Variability in reproductive features and body size of these species seem to reflect physiological constraints imposed by temperature in cold and warm regions. The aspects examined in each chapter of this thesis constitute new antecedents about morphology, taxonomy, and ecology of one of the most representative genus of the family Callianassidae from American coast. Each one of these informations may be considered of especial importance for the management and conservation of the Callichiruss populations from the eastern Pacific. Especially, because both species herein analyzed are frequently collected as bait for commercial and recreational fishing in some small villages along Pacific coast of America.

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-04-16T15:52:11Z No. of bitstreams: 2 Dissertação - Carolina Ramos Caiado Gomes - 2014.pdf: 1331727 bytes, checksum: 59847313ee21fdd7bb1bffc8147d497d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-17T10:55:24Z (GMT) No. of bitstreams: 2 Dissertação - Carolina Ramos Caiado Gomes - 2014.pdf: 1331727 bytes, checksum: 59847313ee21fdd7bb1bffc8147d497d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-17T10:55:24Z (GMT). No. of bitstreams: 2 Dissertação - Carolina Ramos Caiado Gomes - 2014.pdf: 1331727 bytes, checksum: 59847313ee21fdd7bb1bffc8147d497d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-05-23 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Nestedness is a particular pattern of species distribution in metacommunities in which a group of species found in poorer sites is a subset of the group of species found in richer sites. In the beta diversity partition context, nestedness is considered one of beta diversity components, jointly with species turnover. However, it is clear now that this term has been used in a wrong way instead of beta diversity due to richness differences. In specific cases that such richness differences reflect an ordered gain or loss of species between sites, then the nested pattern emerges. In the present work I used the beta diversity partition approach, focusing on the richness differences component, combined with a specific metric of nestedness, the NODF, to explore situations in which the richness differences between sites occur in a nested way considering different systems and scales of study. In the first chapter I use aquatic macroinvertebrates communities to show the importance of spatial position of patches of the same microhabitat in generating nestedness in riffles. I found that patches and riffle sites located in the beginning of the riffles are poorer then patches and riffle sites at the end of the same riffles, and that initial sites are nested in final sites in a same riffle. In the second chapter I use birds and mammals communities in the New World to assess how nestedness varies in latitudinal and longitudinal gradients. Nestedness emerged in several regions in both gradients, and it is always related to richness differences in such gradients combined with directional processes that cause an ordered loss or gain of species. / O aninhamento é um padrão ecológico particular de distribuição de espécies em metacomunidades em que o grupo de espécies encontradas em sítios menos ricos é subconjunto daquele encontrado em sítios mais ricos. No contexto de partição de diversidade beta, o aninhamento era considerado, juntamente com a substituição de espécies, um componente da diversidade beta. Porém, atualmente está claro que este termo estava sendo equivocadamente utilizado para se referir à diversidade beta devido a diferenças de riqueza. Em casos específicos em que tais diferenças de riqueza refletem uma perda ou ganho ordenado de espécies entre sítios emerge, então, o aninhamento. No presente trabalho utilizei a abordagem de partição de diversidade beta, focando no componente das diferenças de riqueza, combinada com o uso de uma métrica específica de aninhamento, o NODF, a fim de explorar situações em que a diferença de riqueza entre sítios ocorre de maneira aninhada, considerando diferentes sistemas e escalas de estudo. No primeiro capítulo utilizo comunidades de macroinvertebrados aquáticos para evidenciar a importância da posição espacial de um mesmo micro-habitat na geração de aninhamento em corredeiras. Encontrei que manchas e trechos no início de corredeiras são menos ricos do que no final de corredeiras, e que para trechos há aninhamento da fauna encontrada no trecho inicial em relação à fauna encontrada no trecho final de uma mesma corredeira. No segundo capítulo utilizo comunidades de aves e mamíferos considerando uma escala que abrange todo o Novo Mundo para avaliar como o aninhamento varia ao longo de gradientes latitudinais e longitudinais. O padrão aninhado emergiu em várias regiões de ambos os gradientes, e está sempre relacionado a diferenças de riquezas existentes nesses gradientes combinada com processos direcionais que levam a perda ou ganho ordenado de espécies.

Plants have spread to almost everywhere in the world. As they disperse, they meet many different environments to which they may be able to adapt. For a plant species to adapt to a new environment, genetic variation is needed. The individuals differ from each other in their genetic composition, which often means differences in phenotypes. Those individuals that manage to reproduce will form the next generation. With different conditions in different environments, it will not be the same phenotypes that reproduce everywhere. In that way, plant species will form into a mosaic of locally adapted populations varying genetically as the species disperses. After the last ice age plants have started to disperse away from the equators. With increasing latitudes come increasing challenges to migrating plants. As plant species disperse northwards along this gradient of varying conditions individuals are selected for cold adaptive traits like flowering time and freezing tolerance, acquired by cold acclimation. In this way, genetic variation from the original populations for these traits becomes sorted out along a latitudinal cline. The aim of this thesis was to understand how selection along a latitudinal gradient has shaped natural variation in cold adaptive traits in plants dispersing northwards, and specifically, to investigate what variation can be observed in phenotypes for these traits and how these traits correlate with genetic variation in genes known to be involved in cold acclimation. In this study significant variation was found in a sample of the model plan Arabidopsis thaliana accessions in cold adaptive traits flowering time and freezing tolerance. A clear latitudinal cline in the cold adaptive traits freezing tolerance for A. thaliana was observed. Analysis of nucleotide polymorphism for the cold responsive ICE1 (inducer of CBF expression 1) transcription factor revealed a haplotype structure with two allelic clades as well as unusually high levels of synonymous polymorphism. Nucleotide polymorphism analysis for the transcription factors CBF1, CBF2 and CBF3 (C-repeat binding factors) that play a key role in regulating the expression of a group of target genes known as the “CBF regulon” showed a distinct geographical haplotype structure. One haplotype was dominant in southern accessions while in the other northern accessions overrepresented. There was a significant effect of CBF haplotype on both freezing tolerance and flowering time even after correcting for latitude. Significant differences in CBF expression levels were found between the different CBF genes as well as between different accessions. Sequence variation at CBF was shown to have a significant effect on expression levels of CBF2. No clear correlations were found between CBF gene expression and freezing tolerance or temperature sensitivity for any of the accessions used in the study. This highlights the complex relationship between sequence variation in candidate genes and gene expression, and the problems associated with unraveling the genetic basis of ecologically important traits.

Cost and benefits of high individual growth rates are likely to vary across different environments leading to geographic differentiation in growth strategies. In ectotherms, habitats constrained by short growing seasons favour rapid growth and development leading to adaptive latitudinal clines in these traits. Geographic variation in growth strategies should be influenced by physiological variation as well as environmental factors, however many of these mechanisms remain largely unexplored. In my thesis, I studied hormonal correlates of growth strategies, and compensatory responses to phenological variation and environmental stress in anuran tadpoles. I tested the hypotheses that fast growing high latitude common frog Rana temporaria tadpoles have higher growth hormone (GH) expression, and low stress hormone (CORT) elevation in response to predator stress. I found no relationship between GH expression and latitude, but CORT response decreased with latitude after 24 hours of predator exposure. Lower CORT response at high latitude can be adaptive as it may enable the tadpoles to maintain high growth in time constrained habitats. I also found that breeding phenology affected latitudinal variation in growth, development and anti-predator strategies. Northern R. temporaria tadpoles were phenotypically more similar to southern tadpoles when breeding occurred early, suggesting that part of the latitudinal variation is plastic and affected by yearly variation in phenology. When time stress was manipulated by delaying hatching, tadpoles were able to compensate by increasing their development and growth during the larval stage, decreasing the cost of the delayed development. In the final study, I found that northern tadpoles showed stronger compensatory growth during the larval stage than southern tadpoles after being delayed by low food, however, temperature manipulation did not induce differences in the compensatory responses. In general, my results highlight the roles of both environmental and genetic variation in determining individual growth strategies. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 735

Increases in global temperatures resulting from climate change have raised concern over potential responses of Arctic charr, <i>Salvelinus alpinus</i>, a cold-adapted freshwater/anadromous fish species in the salmonid family. While various aspects of adult Arctic charr ecology are well established, juvenile, and in particular, young-of-the-year (YOY) ecology is less well understood. The study of early life stages is important because of implications for subsequent population dynamics as well as their particular sensitivity to climate change. In this thesis, I aimed to broaden the scope of knowledge on juvenile Arctic charr from Canadian populations with a particular emphasis on YOY, and thermal habitat use through four studies. An intensive study of juvenile Arctic charr from Lake Hazen, Nunavut, demonstrated a preference during the summer for stream environments, particularly those fed by warm upstream ponds. Charr occupying both stream and nearshore lake habitats were found to feed similarly, with chironomids occurring most frequently in diets. Some older stream-dwelling charr preyed on smaller, younger Arctic charr. Preferred stream occupancy is likely mediated by physical barriers created mainly by water velocity, and by distance from the lake, lake-ice dynamics, low water depth, and turbidity. Water velocities and possibly intercohort competition resulted in stream habitat segregation by size, with YOY mainly found in low velocity pools and back eddies adjacent to stream banks, but not in water velocities greater than 0.1m/s. Greatest charr densities in streams were found in small, shallow, slow-flowing side channels, which are highly susceptible to drought. A discriminant function analysis model based on carbon and nitrogen stable isotope values was used to identify offspring of piscivorous large-form and non-piscivorous small-form Arctic charr morphotypes from Lake Hazen, Nunavut. The adult morphotypes were estimated to contribute approximately equally to the YOY population, however, the morphotype offspring were differentially distributed among sampled nursery sites. Unequal distribution corresponds with prerequisites suggested for the evolution of trophic specialists within a single population that experiences assortative mating based on trophic specialization. An assessment of growth rates and otolith-inferred metabolic rates obtained from YOY from 23 populations over a 27˚ latitudinal gradient demonstrated latitudinal variability consistent with countergradient variation where northern populations demonstrated faster growth and higher metabolic rates compared to southern populations. Countergradient variation (CGV) is defined as genetic variation that counteracts the negative influences of the physical environment, minimizing phenotypic variability along a gradient. Otolith-inferred metabolic rates from free-living animals reflect the average daily energy expenditure of the organism, which incorporate the energetic costs of standard metabolic rate (SMR) and other processes such as feeding, locomotion, thermoregulation, reproduction and growth. As such, variations in otolith-inferred metabolic rates may reflect a combined increase in feeding, activity and SMRs in northern populations. Nevertheless, the phenotypic variation in physiological traits observed here demonstrates the significant adaptability of Arctic charr to different thermal regimes with different growing season lengths. Otolith-inferred temperatures and fork lengths at capture from YOY from two proximal fluvial and lacustrine sites in Labrador were used to compare growth and thermal habitat use between habitat types. Otolith-inferred temperatures were not significantly correlated with air temperatures, suggestive of behavioural thermoregulation by YOY at both sites. The majority of YOY from Kogluktokoluk Brook (fluvial) were found using temperatures consistent with laboratory determined preferred temperatures for juvenile Arctic charr, whereas most Tom’s Pond (lacustrine) YOY were found using temperatures ranging between preferred temperatures and optimal temperatures for growth. Otolith-inferred temperatures were only correlated to fork lengths in Tom’s Pond YOY. The lack of correlation in Kogluktokoluk Brook YOY may reflect resource partitioning occurring as a result of territoriality known to occur among stream salmonids. The limited range of temperatures used by fluvial YOY in this study, particularly the lack of cooler temperatures, suggests that fluvial YOY may face barriers to accessing thermal refugia, and as a result may be particularly vulnerable to climate change. Examining the ecology of juvenile Arctic charr from Canadian populations over a number of spatial scales (i.e. latitudinal, regional and local) highlighted the considerable phenotypic plasticity demonstrated by the species. While physiological plasticity observed over the latitudinal gradient reflected the ability for juvenile Arctic charr to utilize different thermal regimes, the regional comparison between habitat types demonstrated that the ability for juvenile Arctic charr to respond to climate change is likely to vary between habitat types. Further, on a local scale, behavioural plasticity was observed, but was found to be influenced by several regulatory factors. The study of the ecology of juvenile Arctic charr in this thesis has highlighted various factors affecting juvenile Arctic charr in Canada: temperature, water velocity, cover, maternal influences, habitat type and ration. The relative contributions of these factors as well as others which were not directly testable in this thesis (e.g. variability in standard metabolic rate, the role of genetic adaptation) are likely to vary with latitude, populations and habitat types. Deciphering the relative roles of these factors will allow better predictions of responses to climate change.