Hippolyte obliquimanus é um pequeno camarão carídeo da família Hippolitydae. Vários registros na literatura reportaram a ocorrência de hermafroditismo neste grupo. Assim, o objetivo do presente trabalho foi determinar o sistema sexual de H. obliquimanus, testando a hipótese da presença de um sistema gonocórico ou hermafrodita (protândrico ou simultâneo). Os animais foram coletados manualmente a cada dois meses na Praia do Itaguá (Ubatuba/SP) de março/2005 a janeiro/2006. Os animais foram analisados em relação ao sexo e a morfometria quanto ao comprimento da carapaça, a largura máxima do própodo, ao comprimento do dáctilo do pereópodo 3 e ao comprimento do apêndice masculino. Foram realizados experimentos em laboratório para investigar a possível mudança de sexo. Um total de 674 espécimes foi coletado: 211 machos, 339 fêmeas não ovígeras e 124 fêmeas ovígeras. O comprimento da carapaça variou de 0,55 a 3,20 mm, com as fêmeas sendo significativamente maiores que os machos. A distribuição de tamanho foi unimodal, com poucos indivíduos nas maiores classes de tamanho. A razão sexual total desviou significantemente do esperado 1:1 em favor das fêmeas (0,46:1). Houve maior ocorrência de indivíduos no período outono-inverno (75%) que na primavera-verão. Entretanto a razão sexual e a porcentagem de fêmeas ovígeras/total de fêmeas foram praticamente iguais para ambos os períodos sazonais estudados. Observou-se que H. obliquimanus apresenta dimorfismo sexual com relação ao pereópodo 3, não apresenta cincinnuli no pleópodo 1 e não há redução do apêndice masculino nos machos maiores. Não houve mudança de sexo nos animais observados nos experimentos. Em síntese, conclui-se que este perfil denota indícios de uma população com reprodução contínua sazonal, em que as fêmeas são mais abundantes e atingem maiores tamanhos que os machos, os machos apresentam o apêndice masculino bem desenvolvido, não há indivíduos em transição na população. Portanto, a escassez de evidências suportando a protandria de H. obliquimanus permitiu caracterizar a espécie estudada como gonocórica. / Hippolyte obliquimanus is a small caridean shrimp of the Hippolitydae family. Several registers in the literature reported the occurrence of hermaphroditism in this group. Thus, the aim of the present work was to determine the sexual system of H. obliquimanus, testing the hypothesis of the presence of a gonochoric or hermaphroditic (protandric or simultaneous) system. The animals were collected by hand every two months in the Itaguá Beach (Ubatuba/SP) from March 2005 through January 2006. The animals were analyzed in relation to sex and morphometry based on the carapace length, the maximum propodus width, the dactyl length of the pereopod 3 and the masculine appendix length. Experiments in laboratory were accomplished to investigate the possibility of sex change. A total of 674 specimens was collected: 211 males, 339 non ovigerous females and 124 ovigerous females. The carapace length ranged from 0.55 through 3.20 mm, with females being significantly larger than males. The size distribution was unimodal, with few individuals in the larger size classes. The total sex ratio skewed significantly of the expected 1:1 in favour of the females (0.46:1). There was a higher occurrence of individuals in the period fall-winter (75%) than spring-summer. However the sex ratio and the percentage of ovigerous females/total females were practically equals to both seasonal periods studied. It was observed that H. obliquimanus presented sexual dimorphism in relation to the pereopod 3, it didn\'t present cincinnuli in the pleopod 1 and there wasn\'t reduction of the masculine appendix in the larger males. There wasn\'t sex change in the animals observed in the experiments. In synthesis, it was concluded that this profile denoted indications of a population with seasonal continuous reproduction, with females being more abundant and reaching larger sizes than males, males presenting the well developed masculine appendix, and there wasn\'t transitional individuals in the population. Therefore, the paucity of evidence supporting protandry in H. obliquimanus allowed to characterize this studied species as gonochoric.

Hippolyte obliquimanus é um pequeno camarão carídeo da família Hippolitydae. Vários registros na literatura reportaram a ocorrência de hermafroditismo neste grupo. Assim, o objetivo do presente trabalho foi determinar o sistema sexual de H. obliquimanus, testando a hipótese da presença de um sistema gonocórico ou hermafrodita (protândrico ou simultâneo). Os animais foram coletados manualmente a cada dois meses na Praia do Itaguá (Ubatuba/SP) de março/2005 a janeiro/2006. Os animais foram analisados em relação ao sexo e a morfometria quanto ao comprimento da carapaça, a largura máxima do própodo, ao comprimento do dáctilo do pereópodo 3 e ao comprimento do apêndice masculino. Foram realizados experimentos em laboratório para investigar a possível mudança de sexo. Um total de 674 espécimes foi coletado: 211 machos, 339 fêmeas não ovígeras e 124 fêmeas ovígeras. O comprimento da carapaça variou de 0,55 a 3,20 mm, com as fêmeas sendo significativamente maiores que os machos. A distribuição de tamanho foi unimodal, com poucos indivíduos nas maiores classes de tamanho. A razão sexual total desviou significantemente do esperado 1:1 em favor das fêmeas (0,46:1). Houve maior ocorrência de indivíduos no período outono-inverno (75%) que na primavera-verão. Entretanto a razão sexual e a porcentagem de fêmeas ovígeras/total de fêmeas foram praticamente iguais para ambos os períodos sazonais estudados. Observou-se que H. obliquimanus apresenta dimorfismo sexual com relação ao pereópodo 3, não apresenta cincinnuli no pleópodo 1 e não há redução do apêndice masculino nos machos maiores. Não houve mudança de sexo nos animais observados nos experimentos. Em síntese, conclui-se que este perfil denota indícios de uma população com reprodução contínua sazonal, em que as fêmeas são mais abundantes e atingem maiores tamanhos que os machos, os machos apresentam o apêndice masculino bem desenvolvido, não há indivíduos em transição na população. Portanto, a escassez de evidências suportando a protandria de H. obliquimanus permitiu caracterizar a espécie estudada como gonocórica. / Hippolyte obliquimanus is a small caridean shrimp of the Hippolitydae family. Several registers in the literature reported the occurrence of hermaphroditism in this group. Thus, the aim of the present work was to determine the sexual system of H. obliquimanus, testing the hypothesis of the presence of a gonochoric or hermaphroditic (protandric or simultaneous) system. The animals were collected by hand every two months in the Itaguá Beach (Ubatuba/SP) from March 2005 through January 2006. The animals were analyzed in relation to sex and morphometry based on the carapace length, the maximum propodus width, the dactyl length of the pereopod 3 and the masculine appendix length. Experiments in laboratory were accomplished to investigate the possibility of sex change. A total of 674 specimens was collected: 211 males, 339 non ovigerous females and 124 ovigerous females. The carapace length ranged from 0.55 through 3.20 mm, with females being significantly larger than males. The size distribution was unimodal, with few individuals in the larger size classes. The total sex ratio skewed significantly of the expected 1:1 in favour of the females (0.46:1). There was a higher occurrence of individuals in the period fall-winter (75%) than spring-summer. However the sex ratio and the percentage of ovigerous females/total females were practically equals to both seasonal periods studied. It was observed that H. obliquimanus presented sexual dimorphism in relation to the pereopod 3, it didn\'t present cincinnuli in the pleopod 1 and there wasn\'t reduction of the masculine appendix in the larger males. There wasn\'t sex change in the animals observed in the experiments. In synthesis, it was concluded that this profile denoted indications of a population with seasonal continuous reproduction, with females being more abundant and reaching larger sizes than males, males presenting the well developed masculine appendix, and there wasn\'t transitional individuals in the population. Therefore, the paucity of evidence supporting protandry in H. obliquimanus allowed to characterize this studied species as gonochoric.

Flowering plants display diverse reproductive systems, including a variety of gender strategies and mechanisms of clonal propagation. Here, I investigate gender strategies, sex-ratio evolution, and sexual dimorphism in the North American clonal aquatic, Sagittaria latifolia (Alismataceae), which exhibits three sex phenotypes (hermaphrodites, females, males) and two modal sexual systems (monoecy, dioecy). This provides an outstanding opportunity to examine the costs and benefits of combined versus separate sexes. My research focused on the northern range limit in eastern N. America, and on disjunct populations in western N. America. I developed microsatellite (SSR) markers to investigate population genetic structure at several spatial scales, including the clonal structure of local populations to continental patterns. These analyses provided insights on the roles of historical, ecological and reproductive factors in the evolution and maintenance of sexual system diversity. Phenotypic sex ratios varied near continuously from monoecy through subdioecy (three sex phenotypes) to dioecy. A comparison of phenotypic and genotypic sex ratios in dioecious populations demonstrated close correspondence. The northern range limit was characterized by a decline in female frequency and an increased incidence of subdioecy. I evaluated two hypotheses to explain this pattern: (1) increased sex inconstancy in dioecious populations; (2) hybridization between monoecious and dioecious populations. I found support for both hypotheses, although hybridization appears to be the more common pathway to subdioecy. I parameterized a model predicting female frequency and hermaphrodite sex allocation; observed and predicted values were correlated suggesting that subdioecious populations are closer to equilibrium than expected for a clonal perennial. A comparison of eastern and western populations indicated genetic differentiation between monoecy and dioecy in the east, but in the west, due to habitat isolation, geography plays a more important role in genetic differentiation. Evidence from cpDNA haplotype variation indicated that the western range was established following long-distance colonization from the east involving a genetic bottleneck. The discovery of gynodioecious populations of S. latifolia in the west, and the absence of ecological and genetic differentiation between monoecious and dioecious populations, raise the possibility that dioecy may have evolved autochthonously in the west, and more recently than in the eastern range.

Flowering plants display diverse reproductive systems, including a variety of gender strategies and mechanisms of clonal propagation. Here, I investigate gender strategies, sex-ratio evolution, and sexual dimorphism in the North American clonal aquatic, Sagittaria latifolia (Alismataceae), which exhibits three sex phenotypes (hermaphrodites, females, males) and two modal sexual systems (monoecy, dioecy). This provides an outstanding opportunity to examine the costs and benefits of combined versus separate sexes. My research focused on the northern range limit in eastern N. America, and on disjunct populations in western N. America. I developed microsatellite (SSR) markers to investigate population genetic structure at several spatial scales, including the clonal structure of local populations to continental patterns. These analyses provided insights on the roles of historical, ecological and reproductive factors in the evolution and maintenance of sexual system diversity. Phenotypic sex ratios varied near continuously from monoecy through subdioecy (three sex phenotypes) to dioecy. A comparison of phenotypic and genotypic sex ratios in dioecious populations demonstrated close correspondence. The northern range limit was characterized by a decline in female frequency and an increased incidence of subdioecy. I evaluated two hypotheses to explain this pattern: (1) increased sex inconstancy in dioecious populations; (2) hybridization between monoecious and dioecious populations. I found support for both hypotheses, although hybridization appears to be the more common pathway to subdioecy. I parameterized a model predicting female frequency and hermaphrodite sex allocation; observed and predicted values were correlated suggesting that subdioecious populations are closer to equilibrium than expected for a clonal perennial. A comparison of eastern and western populations indicated genetic differentiation between monoecy and dioecy in the east, but in the west, due to habitat isolation, geography plays a more important role in genetic differentiation. Evidence from cpDNA haplotype variation indicated that the western range was established following long-distance colonization from the east involving a genetic bottleneck. The discovery of gynodioecious populations of S. latifolia in the west, and the absence of ecological and genetic differentiation between monoecious and dioecious populations, raise the possibility that dioecy may have evolved autochthonously in the west, and more recently than in the eastern range.

Orientador: Marcelo Antonio Amaro Pinheiro / Resumo: O presente estudo analisa a taxonomia, morfologia externa e interna do sistema reprodutivo e crescimento relativo do camarão-fantasma Callichirus major da costa do Brasil. Para isto, espécimes de C. major foram coletados ao longo de todo o litoral brasileiro e, de forma particular, mensalmente, durante um ano, na Praia do Gonzaga, região Sudeste do Brasil. Um total de 840 indivíduos (316 machos, 524 fêmeas) foram avaliados. Ocorrendo desde o estado do Pará até Santa Catarina, C. major apresentou um rostro com duas projeções anterolaterais triangulares, pedúnculos oculares com pontas obtusas, dáctilo do quelípodo maior dos machos com uma ponta bífida e margem interna lisa, projeção proximal do carpo com margem reta, mero com porção proximal da margem dorsal dentada, quelípodo menor com borda cortante dentada e um dente grande curvado para frente entre as projeções laterais do telso. Estes animais apresentaram diferenças morfológicas marcantes em comparação aos espécimes de C. major procedentes da Florida (EUA), justificando a separação da grande população do Atlântico Ocidental de C. major e determinando uma nova espécie no gênero, Callichirus brasiliensis sp. nov. Nos capítulos desta dissertação que não trataram de taxonomia, optamos por manter o nome da espécie até o momento aceito, C. major. A morfologia reprodutiva externa destes camarões-fantasma se mostrou distinta entre machos, com gonóporos circulares, localizados no quinto par de pereiópodos, e fêmeas, com gonóporos o... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study analyses the taxonomy, external and internal morphology of the reproductive apparatus and relative growth of the ghost shrimp Callichirus major from the coast of Brazil. For this, specimens of C. major were collected along the entire Brazilian coast and, in particular, monthly, for one year, in Gonzaga’s Beach, Southeastern region of Brazil. A total of 840 individuals (316 males, 524 females) were evaluated. Occurring from the state of Pará to Santa Catarina, C. major presented a rostrum with two triangular anterolateral projections, ocular peduncles with obtuse tips, dactyl of the greater chelipod of males with a bifid tip and smooth internal margin, proximal projection of the carpal with straight margin, merus with proximal portion with dentate dorsal margin, smaller chelipod with toothed cutting edge and a large tooth curved forward between the lateral projections of the telson. These animals presented marked morphological differences when compared to specimens of C. major from Florida (USA), justifying the separation of the large Western Atlantic population from C. major and determining a new species in this genus – Callichirus brasiliensis n. sp. In the chapters of this thesis that don’t deal with taxonomy, we chose to keep the name of the species so far accepted, C. major. The external reproductive anatomy of these ghost shrimps was shown to be distinct between males, with circular gonopores located in the fifth pair of pereiopods, and females with ova... (Complete abstract click electronic access below) / Mestre

Les palmiers constituent une famille emblématique de monocotylédones, comprenant 183 genres et environ 2500 espèces distribuées sur tous les continents dans les zones tropicales et subtropicales. Leurs feuilles et leurs stipes, très caractéristiques, les rendent facilement reconnaissables dans la nature. En revanche leurs fleurs passent souvent inaperçues. Elles sont généralement petites (quelques centimètres), trimères, unisexuées, peu colorées (blanches ou vertes) et regroupées sur de grandes inflorescences. Cependant les palmiers présentent une diversité importante au niveau du système sexuel et du nombre d’étamines. Les trois systèmes sexuels principaux des angiospermes : hermaphrodisme, monoécie et dioécie, sont présents chez les palmiers. Le nombre d’étamines varie entre quelques unités (oligandrie) et des dizaines, voire centaines, d’unités (polyandrie) chez certains genres. Nous avons étudié l’évolution du système sexuel et du nombre d’étamines à l’échelle de la famille. Nous avons pour cela utilisé une phylogénie comprenant tous les genres de palmiers, bien résolue, datée et qui a été publiée récemment. Notre étude a montré que l’ancêtre commun à tous les palmiers était probablement monoïque et possédait des fleurs oligandres à 6 étamines. A partir de ces états ancestraux, plusieurs transitions ont eu lieu : vers l’hermaphrodisme et la monoécie d’une part, et vers la polyandrie d’autre part. Dans l’objectif d’initier une recherche sur une éventuelle explication fonctionnelle de l’augmentation du nombre d’étamines, nous avons comparé celui-ci à la production de pollen, en étudiant la quantité totale de pollen produite par les fleurs de 82 espèces. Notre étude a montré que, chez deux sous-familles, les fleurs ont tendance à produire plus de pollen quand le nombre d’étamines est plus élevé. Nous avons également réalisé la phylogénie moléculaire d’une sous-tribu (les Ptychospermatinae) dans laquelle la variation du nombre d’étamines est exceptionnelle. De futures études sur la génétique, le développement, l’écologie et la biologie de la pollinisation sont nécessaires. / Palms (Arecaceae) are an emblematic family of monocots of 183 genera and around 2500 species distributed on all continents, throughout tropical and subtropical areas. Their characteristic leaves and stems make palms immediately recognizable in the field. The inconspicuous palm flowers are usually considered as rather dull. They are usually small (a few centimetres), trimerous, often unisexual, colourless (white or greenish) and grouped into huge inflorescences. However palms exhibit a large diversity in sexual system and in stamen number, diversity that is still poorly understood. The three main sexual systems of angiosperm, hermaphroditism, dioecy and monoecy are present in palms. Stamen number ranges between a few units (oligandry) to several dozens and even several hundreds of units (polyandry) in some genera. We studied the evolution of sexual system and stamen number at the family level. We used as historical framework a well-supported and dated phylogeny, published recently. Our study showed that the putative ancestor of palms was monoecious and bore oligandrous flowers with 6 stamens. From these ancestral states, several transitions occurred: towards hermaphroditism and dioecy and towards polyandry respectively. In order to initiate a research on a possible functional significance of increase in stamen number, we investigated the relationship between stamen number and pollen production, by extracting the total pollen content from flowers of 82 species. Our study showed a tendency towards higher pollen production when the number of stamen increases in two subfamilies. We also produced molecular phylogeny of a subtribe (Ptychospermatinae) in which the range of variation in stamen number is exceptional. Further investigations into genetic, developmental, ecology and pollination biology are needed.

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