Foraging presents a significant challenge for neonatal predators. Both physical maturation and predatory experience may improve predatory abilities. To tease apart which improvements in predatory abilities were due to increased maturation and which to increased experience, several experiments that isolated the effects of maturation and experience were conducted. Individual whitespotted bamboosharks, Chiloscyllium plagiosum, improved predatory efficiency with both maturation and experience. Physical maturation, when isolated from experience, improved predatory efficiency of naïve sharks foraging on shrimp, an elusive prey, but not of sharks foraging on worms, a non-elusive prey. Predatory experience, when isolated from maturation, improved predatory efficiency of sharks foraging on worms but not of sharks foraging on shrimp. Both maturation and experience are important in the development of whitespotted bamboosharks' predatory abilities and may influence the type of prey they can exploit. To determine whether whitespotted bamboosharksare able to retain the ability to capture and eat prey after a period of prey absence, sharks that had 20 days of foraging experience were denied access to live prey for 18 days, after which they were re-exposed to live prey. Predatory efficiency of sharks did not decrease during the 18 day prey-absence period. After sharks were re-exposed to live prey, their predatory efficiency was similar to that of sharks of the same age with equivalent experience but no prey-absence period, but was higher than that of naïve sharks. Whitespotted bamboosharks retain the ability to catch and consume prey after a short period of prey absence. This retention may improve their ability to forage on prey that is spatially or temporally patchy. To determine whether experience with one prey type affects the whitespotted bambooshark's ability to forage on novel prey, sharks that had 20 days of experience foraging on one type of prey (either worms or shrimp) were given foraging trials with the other prey. Experience with one prey improved sharks abilities to forage on novel; sharks foraging on novel prey were as efficient as sharks that had foraged on that prey for 20 days. Whitespotted bamboosharks can maintain or easily modify many predatory skills when foraging on novel prey.

Diss. (sammanfattning) Umeå : Univ., 2008. / Härtill 4 uppsatser.

Aranhas orbitelas realizam comportamentos de busca quando uma presa, fixada no centro ou na periferia da teia, é suprimida. A fim de investigar os componentes da memória predatória relacionados com a localização espacial e com o tamanho da presa, foram realizados três exerimentos com a aranha Argiope argentata (Fabricius, 1775). No Experimento 1, buscou-se saber se haveria diferenças entre as seqüências de busca executadas no caso da supressão de uma mosca fixada no centro e de uma mosca fixada na periferia da teia. No Experimento 2, replicou -se o Experimento 1, usando como presa um fragmento de tenébrio, mais pesado do que a mosca. No Experimento 3, tentou-se verificar se as aranhas gastariam mais tempo buscando uma presa armazenada na periferia da teia quando esta presa fosse experimentalmente deslocada para outro local. Os resultados mostram que A. argentata discrimina, na sua busca, presas fixadas no centro ou na periferia da teia, e que têm um tempo médio de busca maior no caso de uma presa de tamanho maior (Experimentos 1 e 2). As aranhas contudo parecem não discriminar a parte de cima da parte de baixo da região periférica de sua teia (Experimento 3). As informações obtidas na presente pesquisa contribuem para a formulação de modelos a respeito do funcionamento da memória em aranhas. / Orbweb spiders perform searching movements when a prey attached to the hub or hoarded at the periphery of the web is suppressed. We here examined the question of a possible memory representation of the attachment site and of prey size in three experiments with Argiope argentata (Fabricius, 1775). In Experiment 1, we looked for differences between search sequences performed when a domestic fly was suppressed, when attached to the hub or hoarded at the periphery of the web. The procedure of Experiment 1 was replicated in Experiment 2, but prey was then part of a larva of tenebrium, heavier than a fly. In Experiment 3, we tested the hypothesis that a spider would spend more time searching for a prey when the hoarding site of this prey is changed relatively to initial experience. Results show that A. argentata perform different searching sequences according to the site of attachment of a prey (hub vs. periphery) and tends to spend more time searching for heavier prey (Experiments 1 and 2). There was however no discrimination of upper or lower parts of the web as to searching behavior (Experiment 3). The present results contribute to the formulation of memory models in spiders.

Aranhas orbitelas realizam comportamentos de busca quando uma presa, fixada no centro ou na periferia da teia, é suprimida. A fim de investigar os componentes da memória predatória relacionados com a localização espacial e com o tamanho da presa, foram realizados três exerimentos com a aranha Argiope argentata (Fabricius, 1775). No Experimento 1, buscou-se saber se haveria diferenças entre as seqüências de busca executadas no caso da supressão de uma mosca fixada no centro e de uma mosca fixada na periferia da teia. No Experimento 2, replicou -se o Experimento 1, usando como presa um fragmento de tenébrio, mais pesado do que a mosca. No Experimento 3, tentou-se verificar se as aranhas gastariam mais tempo buscando uma presa armazenada na periferia da teia quando esta presa fosse experimentalmente deslocada para outro local. Os resultados mostram que A. argentata discrimina, na sua busca, presas fixadas no centro ou na periferia da teia, e que têm um tempo médio de busca maior no caso de uma presa de tamanho maior (Experimentos 1 e 2). As aranhas contudo parecem não discriminar a parte de cima da parte de baixo da região periférica de sua teia (Experimento 3). As informações obtidas na presente pesquisa contribuem para a formulação de modelos a respeito do funcionamento da memória em aranhas. / Orbweb spiders perform searching movements when a prey attached to the hub or hoarded at the periphery of the web is suppressed. We here examined the question of a possible memory representation of the attachment site and of prey size in three experiments with Argiope argentata (Fabricius, 1775). In Experiment 1, we looked for differences between search sequences performed when a domestic fly was suppressed, when attached to the hub or hoarded at the periphery of the web. The procedure of Experiment 1 was replicated in Experiment 2, but prey was then part of a larva of tenebrium, heavier than a fly. In Experiment 3, we tested the hypothesis that a spider would spend more time searching for a prey when the hoarding site of this prey is changed relatively to initial experience. Results show that A. argentata perform different searching sequences according to the site of attachment of a prey (hub vs. periphery) and tends to spend more time searching for heavier prey (Experiments 1 and 2). There was however no discrimination of upper or lower parts of the web as to searching behavior (Experiment 3). The present results contribute to the formulation of memory models in spiders.

A memória é considerada por muitos pesquisadores como um dos produtos mais fascinantes da evolução biológica, justamente por proporcionar aos animais a vantagem adaptativa de se utilizar de uma experiência prévia para a solução de problemas necessários para a sobrevivência. Os animais se utilizam de processos mnemônicos durante o forrageamento, a seleção de parceiros sexuais, seleção de habitat e a preferência alimentar. As aranhas são um modelo interessante em estudos de memória e há evidências do uso de experiências passadas na otimização do forrageio: a teia permite que as aranhas capturem e armazenem mais de um item alimentar. Há carência na literatura de estudos comparativos evolutivos da memória, o que dificulta identificar as possíveis pressões seletivas. O primeiro objetivo deste trabalho foi fazer um estudo comparativo de aspectos da memória predatória em aranhas do grupo Orbiculariae. Este grupo é monofilético e tem como principal sinapomorfia a construção de teia orbicular. Porém, ao longo da evolução, o padrão de teia foi se modificando desde uma estrutura plana até uma tridimensional. Tais modificações podem ter gerado diferenças comportamentais e no sistema de memória dessas aranhas. Por este motivo, o outro objetivo, foi traçar a evolução da memória dentro do grupo. Delinearam-se três grupos de estudo com sete espécies. Na condição natural, observou-se a captura de duas presas sucessivas. Na condição experimental I, ofereceu-se uma primeira presa (p1) à aranha e, em seguida, ofereceu-se uma segunda (p2); durante o deslocamento da aranha até p2, retirou-se p1 da teia. Na condição II, ao invés de se oferecer p2, a aranha foi atraída à periferia (simulando a queda de p2). No deslocamento da aranha até a fonte de vibração removeu-se p1. O indício de memória é observado quando, na supressão da presa, a aranha executa um comportamento denominado Busca. Neste, a aranha executa sacudidas/detecções dos fios no centro/refúgio da teia. A busca por p1 roubada foi observada em todas as espécies estudadas, exceto em Z. geniculata no grupo I. A presença de p2 parece interferir na expressão da memória de p1; deixar p2 na teia enquanto busca por p1, aumenta as chances de p2 também ser roubada por ação dos cleptoparasitas. Zosis apresenta algumas peculiaridades, entre elas a ausência de veneno. Dessa forma, o tempo gasto durante a imobilização de p2 parece ser suficiente para causar o esquecimento de p1. Todas as espécies buscaram por p1 quando não houve oferta de p2, inclusive Zosis. O tempo de busca, na condição I, diminui da base de Araneoidea até as famílias mais derivadas. No grupo II, há uma aparente inversão do sinal filogenético e o tempo de busca aumenta na família mais derivada. A estrutura da teia tridimensional parece ser mais complexa e, por este motivo, exigiria um sistema de navegação espacial também mais complexo quando comparado às aranhas orbitelas. A construção da teia parece ter sido crucial para a captura e armazenamento de presas excedentes, e tal comportamento, juntamente com a diversificação das teias, favoreceu a variação e evolução da memória na Ordem Araneae / Memory is one of the most fascinating products of biological evolution, because it endows animals with the adaptive use a prior experiences to solve survival problems. Animals use mnemonic processes during foraging, selection of sexual partners, habitat selection, and feeding preference. Spiders are an interesting model for studies of memory, and there is evidence of their using of past experiences in optimizing foraging: the web allows the spiders to capture and store more than one food item. In literature, there are few comparative studies, and no one about the evolution of memory, making it difficult to identify the possible selective pressures on memory. The first objective here was to make a comparative study on the aspects of predatory memory in spiders of the group Orbiculariae. This group is monophyletic and its main synapomorphy is building an orbicular web. However, during evolution, the web pattern changed from a flat to a three-dimensional structure. Such changes may have caused differences in behavior and memory. For that reason, another goal was to trace the evolution of memory within the group. We used three experimental groups with seven species each. In natural conditions, there was an observation of the capture of two successive preys. In the experimental condition I, a first prey (p1) was offered to the spider and, subsequently, another prey (p2) was offered; during the locomotion of the spider towards p2, p1 was removed from the web. In condition II, instead of offering p2, the spider was attracted to the periphery (simulating the fall of p2). As the spider moved towards the source of vibration, p1 was removed. The evidence of memory is observed when, in the suppression of the prey, the spider performs a behavior called search behavior: the spider runs plucking on threads in the web hub/retreat. The search for stolen p1 was observed in all species studied, except for Zosis geniculata in group I. The presence of p2 appears to interfere with the expression of p1 memory, and also leaving p2 on the web while searching for p1, increases the chances of having p2 stolen by the action of kleptoparasites. Zosis presents some peculiarities, including the absence of poison glands, leading to a prolonged immobilization of p2, in a time lag that could then be sufficient forget p1. All species sought by p1 when there was no offer of p2, including Zosis. The search time, in condition I, decreases from the base of Araneoidea until the most derived families. In group II, there is an apparent reversal of the phylogenetic signal and the search time increases in the most derived family. The three-dimensional structure of the derived webs seems to be more complex and, therefore, it would require a spatial navigation system also more complex if compared to the flat orbweb. The construction of the web seems to have been crucial for prey capture and storage of surpluses, and such behavior, along with the diversification of the webs, favored the variation and evolution of memory in the Order Araneae

A memória é considerada por muitos pesquisadores como um dos produtos mais fascinantes da evolução biológica, justamente por proporcionar aos animais a vantagem adaptativa de se utilizar de uma experiência prévia para a solução de problemas necessários para a sobrevivência. Os animais se utilizam de processos mnemônicos durante o forrageamento, a seleção de parceiros sexuais, seleção de habitat e a preferência alimentar. As aranhas são um modelo interessante em estudos de memória e há evidências do uso de experiências passadas na otimização do forrageio: a teia permite que as aranhas capturem e armazenem mais de um item alimentar. Há carência na literatura de estudos comparativos evolutivos da memória, o que dificulta identificar as possíveis pressões seletivas. O primeiro objetivo deste trabalho foi fazer um estudo comparativo de aspectos da memória predatória em aranhas do grupo Orbiculariae. Este grupo é monofilético e tem como principal sinapomorfia a construção de teia orbicular. Porém, ao longo da evolução, o padrão de teia foi se modificando desde uma estrutura plana até uma tridimensional. Tais modificações podem ter gerado diferenças comportamentais e no sistema de memória dessas aranhas. Por este motivo, o outro objetivo, foi traçar a evolução da memória dentro do grupo. Delinearam-se três grupos de estudo com sete espécies. Na condição natural, observou-se a captura de duas presas sucessivas. Na condição experimental I, ofereceu-se uma primeira presa (p1) à aranha e, em seguida, ofereceu-se uma segunda (p2); durante o deslocamento da aranha até p2, retirou-se p1 da teia. Na condição II, ao invés de se oferecer p2, a aranha foi atraída à periferia (simulando a queda de p2). No deslocamento da aranha até a fonte de vibração removeu-se p1. O indício de memória é observado quando, na supressão da presa, a aranha executa um comportamento denominado Busca. Neste, a aranha executa sacudidas/detecções dos fios no centro/refúgio da teia. A busca por p1 roubada foi observada em todas as espécies estudadas, exceto em Z. geniculata no grupo I. A presença de p2 parece interferir na expressão da memória de p1; deixar p2 na teia enquanto busca por p1, aumenta as chances de p2 também ser roubada por ação dos cleptoparasitas. Zosis apresenta algumas peculiaridades, entre elas a ausência de veneno. Dessa forma, o tempo gasto durante a imobilização de p2 parece ser suficiente para causar o esquecimento de p1. Todas as espécies buscaram por p1 quando não houve oferta de p2, inclusive Zosis. O tempo de busca, na condição I, diminui da base de Araneoidea até as famílias mais derivadas. No grupo II, há uma aparente inversão do sinal filogenético e o tempo de busca aumenta na família mais derivada. A estrutura da teia tridimensional parece ser mais complexa e, por este motivo, exigiria um sistema de navegação espacial também mais complexo quando comparado às aranhas orbitelas. A construção da teia parece ter sido crucial para a captura e armazenamento de presas excedentes, e tal comportamento, juntamente com a diversificação das teias, favoreceu a variação e evolução da memória na Ordem Araneae / Memory is one of the most fascinating products of biological evolution, because it endows animals with the adaptive use a prior experiences to solve survival problems. Animals use mnemonic processes during foraging, selection of sexual partners, habitat selection, and feeding preference. Spiders are an interesting model for studies of memory, and there is evidence of their using of past experiences in optimizing foraging: the web allows the spiders to capture and store more than one food item. In literature, there are few comparative studies, and no one about the evolution of memory, making it difficult to identify the possible selective pressures on memory. The first objective here was to make a comparative study on the aspects of predatory memory in spiders of the group Orbiculariae. This group is monophyletic and its main synapomorphy is building an orbicular web. However, during evolution, the web pattern changed from a flat to a three-dimensional structure. Such changes may have caused differences in behavior and memory. For that reason, another goal was to trace the evolution of memory within the group. We used three experimental groups with seven species each. In natural conditions, there was an observation of the capture of two successive preys. In the experimental condition I, a first prey (p1) was offered to the spider and, subsequently, another prey (p2) was offered; during the locomotion of the spider towards p2, p1 was removed from the web. In condition II, instead of offering p2, the spider was attracted to the periphery (simulating the fall of p2). As the spider moved towards the source of vibration, p1 was removed. The evidence of memory is observed when, in the suppression of the prey, the spider performs a behavior called search behavior: the spider runs plucking on threads in the web hub/retreat. The search for stolen p1 was observed in all species studied, except for Zosis geniculata in group I. The presence of p2 appears to interfere with the expression of p1 memory, and also leaving p2 on the web while searching for p1, increases the chances of having p2 stolen by the action of kleptoparasites. Zosis presents some peculiarities, including the absence of poison glands, leading to a prolonged immobilization of p2, in a time lag that could then be sufficient forget p1. All species sought by p1 when there was no offer of p2, including Zosis. The search time, in condition I, decreases from the base of Araneoidea until the most derived families. In group II, there is an apparent reversal of the phylogenetic signal and the search time increases in the most derived family. The three-dimensional structure of the derived webs seems to be more complex and, therefore, it would require a spatial navigation system also more complex if compared to the flat orbweb. The construction of the web seems to have been crucial for prey capture and storage of surpluses, and such behavior, along with the diversification of the webs, favored the variation and evolution of memory in the Order Araneae

O Colículo Superior (SC) é conhecido por apresentar diversas funções que modulam a caça predatória. Neste estudo, investigamos as funções do SC em ratos expostos a caça de insetos. Primeiramente, verificamos que o comportamento predatório induz uma distinta ativação da porção lateral do SC (SCl). Para entender as potenciais funções dessa região colicular, foi analisado o comportamento predatório antes e após lesões bilaterais iontoforéticas por NMDA do SCl. Animais com SCl lesados ficaram menos motivados a perseguirem as baratas, falharam para se orientarem na direção do movimento das presas e quando tentaram capturar as presas, eles apresentaram sérios déficits para capturá-las e segurá-las eficientemente. Por outro lado, animais com lesões da porção medial do SC (SCm) apresentaram apenas um aumento da latência para iniciar a caça, enquanto os outros parâmetros não diferiram significantemente dos animais intactos. Posteriormente, examinamos as conexões eferentes do SCl e do SCm usando como traçador anterógrado a leucoaglutinina do Phaseolus vulgaris. Notamos projeções densas do SCl para a região rostral da coluna lateral da matéria cinzenta periaquedutal (PAGl), um setor criticamente envolvido no controle dos aspectos motivacionais relacionados aos comportamentos de caça predatória e forrageamento. Além disso, o SCl se projeta densamente para o tálamo dorsal, especificamente para os núcleos ventral lateral, central medial e paracentral do tálamo, os quais sabemos que se projetam para setores estriatais ou para áreas motoras corticais, que provavelmente estão envolvidas no ajuste da ação motora durante a captura das presas. O SCm, por sua vez, aferenta densamente a coluna dorsolateral da PAG, núcleo cuneiforme, e núcleos reticulares mesencefálico e pontino, que são setores envolvidos na elaboração de respostas defensivas, além disso, o SCm se projeta esparsamente para os núcleos posterior lateral e suprageniculado do complexo geniculado medial / The superior colliculus is classically known to present a number of functions that fit hunting behavior. In the present study, we investigate the potential roles of the superior colliculus in rats displaying insect hunting. First, we have found that predatory hunting induces a distinct activation of the lateral region of the intermediate layer of the superior colliculus (SCl). To understand the potential roles of this collicular region, we analyzed the hunting performance before and after iontophoretic NMDA lesions bilaterally placed into the SCl. Animals with SCl lesions were clearly less motivated to pursue the roaches, failed to orient themselves toward the moving prey, and whenever the SCl-lesioned rats tried to catch the roaches, they presented serious deficits to capture and hold them efficiently. Next, we examined the SCl efferents connections using Phaseolus vulgaris leucoagglutinin as an anterograde tracer. Of particular relevance, we noted that the SCl projects to the rostral lateral periaqueductal gray, a site critically involved in controlling motivational drive to chase prey and forage. In addition, the SCl also present particularly strong projections to the dorsal thalamus, aimed at the ventral lateral, ventral medial, central medial and paracentral nuclei of thalamus, all of which known to project either to striatal sites or to cortical motor areas, likely to be involved in adjusting the motor action during prey capture. Therefore, the SCl, which seems to present cells responding to prey displacement in the temporal field, presents important arms to the periaqueductal gray and dorsal thalamic sites, influencing, respectively, the motivational drive and the motor skills to hunt

In the last decades, there has been a growing interest in studying particular those arthropods who have an important role in agroecosystems. For example, they are natural enemies of pests and therefore they are considered to be beneficial organisms. However, these beneficial arthropods may be negatively affected by the application of chemicals under the management of agroecosystems and their potential to inhibit pests can be significantly reduced. Such organisms certainly include spiders which occure in abundant numbers practically in all types of terrestrial habitats including agricultural ecosystems where they have a role of very important predators. Therefore, the thesis focused on current issues of pesticides, especially from the view of their negative effects on behavioral modification of beneficial invertebrate organisms in agricultural crops. The theoretical part is devoted to a brief characteristics of pesticides, their sublethal effects on non-target organisms and the importance of spiders as natural regulators of pests in agroecosystems. The practical part describes the experiment whereconventionally used agrochemicals were tested the influence of the herbicide and desiccant Basta 15, the Arrest preparation and their combination (mixture Basta 15 + Arrest) on spiders genus Pardosa. I focused on the side effects of these solutions, specifically on the modification of predatory behavior and on the mortality of spiders. It has been shown that agrochemicals affect the predation successfulness of spiders. From the short term and the long term point of view, it has been shown that spiders treated with the tested preparations killed less prey than the individuals in the control group which were treated only with distilled water. The dependence of mortality and the number of killed prey on the size and sex has not been proved. Preparations Basta 15 and the mixture caused significantly higher mortality of spiders. The Arrest preparation did not increase the mortality.

O Colículo Superior (SC) é conhecido por apresentar diversas funções que modulam a caça predatória. Neste estudo, investigamos as funções do SC em ratos expostos a caça de insetos. Primeiramente, verificamos que o comportamento predatório induz uma distinta ativação da porção lateral do SC (SCl). Para entender as potenciais funções dessa região colicular, foi analisado o comportamento predatório antes e após lesões bilaterais iontoforéticas por NMDA do SCl. Animais com SCl lesados ficaram menos motivados a perseguirem as baratas, falharam para se orientarem na direção do movimento das presas e quando tentaram capturar as presas, eles apresentaram sérios déficits para capturá-las e segurá-las eficientemente. Por outro lado, animais com lesões da porção medial do SC (SCm) apresentaram apenas um aumento da latência para iniciar a caça, enquanto os outros parâmetros não diferiram significantemente dos animais intactos. Posteriormente, examinamos as conexões eferentes do SCl e do SCm usando como traçador anterógrado a leucoaglutinina do Phaseolus vulgaris. Notamos projeções densas do SCl para a região rostral da coluna lateral da matéria cinzenta periaquedutal (PAGl), um setor criticamente envolvido no controle dos aspectos motivacionais relacionados aos comportamentos de caça predatória e forrageamento. Além disso, o SCl se projeta densamente para o tálamo dorsal, especificamente para os núcleos ventral lateral, central medial e paracentral do tálamo, os quais sabemos que se projetam para setores estriatais ou para áreas motoras corticais, que provavelmente estão envolvidas no ajuste da ação motora durante a captura das presas. O SCm, por sua vez, aferenta densamente a coluna dorsolateral da PAG, núcleo cuneiforme, e núcleos reticulares mesencefálico e pontino, que são setores envolvidos na elaboração de respostas defensivas, além disso, o SCm se projeta esparsamente para os núcleos posterior lateral e suprageniculado do complexo geniculado medial / The superior colliculus is classically known to present a number of functions that fit hunting behavior. In the present study, we investigate the potential roles of the superior colliculus in rats displaying insect hunting. First, we have found that predatory hunting induces a distinct activation of the lateral region of the intermediate layer of the superior colliculus (SCl). To understand the potential roles of this collicular region, we analyzed the hunting performance before and after iontophoretic NMDA lesions bilaterally placed into the SCl. Animals with SCl lesions were clearly less motivated to pursue the roaches, failed to orient themselves toward the moving prey, and whenever the SCl-lesioned rats tried to catch the roaches, they presented serious deficits to capture and hold them efficiently. Next, we examined the SCl efferents connections using Phaseolus vulgaris leucoagglutinin as an anterograde tracer. Of particular relevance, we noted that the SCl projects to the rostral lateral periaqueductal gray, a site critically involved in controlling motivational drive to chase prey and forage. In addition, the SCl also present particularly strong projections to the dorsal thalamus, aimed at the ventral lateral, ventral medial, central medial and paracentral nuclei of thalamus, all of which known to project either to striatal sites or to cortical motor areas, likely to be involved in adjusting the motor action during prey capture. Therefore, the SCl, which seems to present cells responding to prey displacement in the temporal field, presents important arms to the periaqueductal gray and dorsal thalamic sites, influencing, respectively, the motivational drive and the motor skills to hunt

Le stress prénatal est un sujet d'intérêt éthologique croissant en raison de ses effets sur la santé humaine et le bien-être des animaux. Cette thése de doctorat s’intéresse à la seiche Sepia officinalis, un modèle pratique dans lequel la progéniture en développement peut être séparée de leurs mères pour examiner diverses sources potentielles de stress en isolement expérimental. Plusieurs catégories de facteurs de stress ont été appliquées aux embryons et aux juvéniles et la progéniture résultante a été testée dans une série d'épreuves physiologiques et comportementales. L'objectif était de déterminer si différents types de stress prénatal affectent la seiche et, dans l'affirmative, comment ces effets se transmettent. Les données présentées démontrent que les stresseurs appliqués aux femelles reproductrices (stress maternel), ainsi que les stresseurs appliqués directement aux embryons (stress embryonnaire), affectent le comportement postnatal (y compris la structuration corporelle, la latéralisation cérébrale, la prédation et les schémas d'activité) la mémoire et / ou la neurobiologie (y compris les concentrations et le renouvellement de la monoamine, la taille des différents lobes cérébraux et la division cellulaire). Les résultats mettent en évidence la présence de trois voies par lesquelles le stress peut exercer des effets: sur le nombre de descendants produits par la femelle, la transmission de la femelle à sa progéniture et directement sur la progéniture elle-même. Les expériences ont également démontré qu'un facteur de stress complètement artificiel (lumière forte) affectait un éventail plus large de comportements chez la progéniture qu’un stress naturel (odeur de prédateur). Enfin, les données ont montré que l'environnement d'incubation et d’élevage peuvent également affecter la progéniture et méritent donc une attention particulière dans la formulation et l'interprétation des expériences avec cette espèce. Ces découvertes informent à la fois les pratiques de bien-être des seiches et d'autres céphalopodes (par exemple, réduisent la manipulation pour maximiser la reproduction) et élucident et renforcent les principes éthologiques qui s'appliquent au stress animal en général (par exemple la transmission des effets de stress de la mère à la progéniture). Compte tenu des informations fournies ici et dans de nombreuses autres études, la seiche et d'autres céphalopodes devraient continuer à servir de modèles comportementaux en éthologie et en biologie en général. / Prenatal stress is a subject of growing ethological interest due to its effects on human health and animal welfare. This Ph.D. thesis utilizes the cuttlefish Sepia officinalis, a convenient model in which developing offspring can be separated from their mothers to examine various potential sources of stress in experimental isolation. Several categories of stressors were applied to cuttlefish and cuttlefish eggs and the resulting offspring were tested in a range of physiological and behavioral tests. The goal was to determine if various types of prenatal stress affect cuttlefish, and if so, how these effects are transmitted. The data presented demonstrate that both stressors applied to reproducing females (maternal stress), as well as stressors applied directly to embryos (embryonic stress), affected post-natal behavior (including body patterning, brain lateralization, predation and activity patterns), learning, memory and/or neurobiology (including monoamine concentrations and turnover, the size of various brain lobes and cell division). The results highlight the presence of three pathways by which stress can exert effects: on the number of offspring produced by the female, transmission from the female to her offspring and directly on the offspring themselves. The experiments also demonstrated that a completely artificial stressor (bright light) affected a wider range of behaviors in offspring than a natural-occurring one (predator odor). Finally, the data showed that incubation and spawning environment can also affect offspring, and thus deserve attention in the formulation and interpretation of experiments with this species. These findings inform both welfare practices for cuttlefish and other cephalopods (e.g. reduce handling to maximize reproduction) as well as elucidating and reinforcing ethological principles that apply to animal stress in general (e.g. the transmission of stress effects from mother to offspring). Given the insight provided here and in numerous other studies, cuttlefish and other cephalopods should continue to serve as behavioral models in ethology and biology in general.