The praying mantis (Mantis religiosa) is the only representative of the order Mantodea in central Europe. Within Czech Republic, this species is distributed mostly on xerothermic localities in southern Moravia. However, M. religiosa has been spreading more to the north not only in Czech Republic, but also in other Europian countries recently. The aim of this study was to reconstruct phylogeography based on genetic markers. It seems that studied species was distributed at least in three lineages in Europe, which could be connected with glacial refugias. First lineage was spread to the north probably from Pyrenean peninsula, second lineage from Crimea peninsula and third lineage from Balkan area. Nine microsatellite loci were tested and will be used for consequent sctudy of phylogeography and distribution of M. religiosa within Europe. Keywords: Mantis religiosa, mtDNA, microsatellite, expansion, phylogeography, phylogeny.

Master of Science / Division of Biology / Samantha M. Wisely / Range-wide estimates of shorebird (Aves: Charadriiformes) populations suggest sharp declines in population sizes across a range of species. Efforts to accurately assess the conservation status of wild populations are becoming increasingly vital to species management. One shorebird of conservation concern, the Buff-breasted Sandpiper (Tryngites subruficollis), is a New World migrant which winters in southeastern South America and breeds in the arctic. To establish an updated conservation status for Buff-breasted Sandpipers, we conducted a molecular survey of wild populations on spatial and temporal scales. We analyzed patterns of global population structure, demographic trends, and phylogeography using nine polymorphic microsatellites and two mitochondrial DNA (mtDNA) markers, cytochrome b and the control region, among 477 individuals across their distributional range. To empirically assess the impact of population declines on genetic diversity, we also surveyed segments of the same two mtDNA markers from 220 museum specimens collected across a 135-year period. Contemporary microsatellite and mtDNA analyses revealed that Buff-breasted Sandpipers are admixed on a global scale, with effective population size estimates ranging from 2,657 to 16,400 birds and no signal of a recent genetic bottleneck. Contemporary mtDNA analyses suggested a pattern of haplotype diversity consistent with a historic radiation from a single refugium which we estimated to have occurred between 8,000−45,000 years before present. Using five measures of mtDNA diversity (haplotype and nucleotide diversity, trend analyses of haplotype richness, Watterson’s estimate of theta, and phi-statistics), as well as a Bayesian Skyline reconstruction of demographic trends in effective population size (N[subscript]e[subscript]f), we concluded that substantial mtDNA diversity and N[subscript]e[subscript]f had not been lost as a result of the population declines in this species. While genetic diversity did not appear to have been lost due to population losses, management efforts must focus on preventing future losses in order for wild populations to remain viable. Our results suggested that the global population of Buff-breasted Sandpipers should be treated as a single, panmictic conservation unit and that successful management must focus on preventing further declines and habitat fragmentation.

Les patrons de diversité sont des états temporaires d'une dynamique de changements écologiques et évolutifs. Les politiques de conservation doivent intégrer cette dynamique et les priorités de conservation s'orienter vers les processus qui produisent et maintiennent cette diversité. Préserver la biodiversité, sans mesurer toutes ces facettes, nécessite de rechercher des substituts biologiques ou écologiques. Une démarche originale est d'évaluer la capacité de la phylogéographie à définir ces substituts. En effet, la phylogéographie permet de fournir des indices sur les zones de diversification et sur les entités (e.g. evolutionary significant units) qui soutiennent celles-ci au niveau intraspécifique. L'objectif général de ce travail est d'évaluer, en terme de cibles et de substituts, l'apport de la phylogéographie à la conservation de la flore méditerranéenne. Nos analyses s'appuient sur deux zones d'étude en région Provence-Alpes-Côte d'Azur intégrant deux plantes endémiques restreinte: le littoral des Alpes maritimes et l'endémique Acis nicaeensis, la basse Provence calcaire et l'endémique Arenaria provincialis. Chez Arenaria provincialis, les résultats montrent une répartition spatiale des phénomènes de persistance et de divergence et le rôle clé de la phylogéographie dans la recherche des critères optimaux de planification des actions de conservation. L'originalité génétique et écologique des populations d'Acis nicaeensis est mise en exergue à faible échelle. Leurs vulnérabilités face à l'urbanisation appellent à des actions de conservation ciblées sur des surfaces restreintes afin de préserver l'héritage évolutif de l'espèce. / Diversity patterns are temporary state in a dynamic continuum of ecological and evolutionary changes. Thus, conservation policies have to integrate this dynamics and Conservation priorities have to be oriented towards the processes which generate and maintain diversity. Conserving biodiversity without needing to measure all its different components, it is necessary to search for biological and ecological surrogates. An original approach is to assess the capacity of phylogeography to define these surrogates. Indeed, the phylogeography allows providing indices for diversification zonation and can be used to delineate the units (e.g. evolutionary significant units) that support diversification at intraspecific level. The main objective of this work is to evaluate, in terms of targets and surrogates, the role of phylogeography for conservation of the Mediterranean flora. We based our analyses on two study areas of the South-East France harbouring two endemic species: the coastal ranges of Maritime Alps where Acis nicaeensis grows, and the calcareous Provence where Arenaria provincialis is found. The phylogeography of Arenaria provincialis revealed a spatial distribution of persistence and divergence. Our study highlights the critical role of phylogeography in the search for optimal criteria for defining the conservation strategies. The marked differences of genetic and ecology in populations of Acis nicaeensis but also in terms of its vulnerability to urbanization are highlighted in a local scale. The results demonstrate the need of conservation actions designed for small areas to avoid the loss of Acis nicaeensis evolutionary legacy.

Garry oak (Quercus garryana Douglas ex. Hook) is a white oak (Quercus sect. Quercus) with a geographic range extending from southwestern BC to south-central California. It is the only native white oak in BC and Washington, and is the northernmost species of the California Floristic Province-Pacific Northwest white oak clade. I used molecular methods to address the following questions: 1) What are the patterns of genetic variation within Garry oak? 2) How do these patterns vary geographically, and how did the spatial distribution of the gene lineages come to occupy its current geographical range? 3) Does Garry oak show evidence of genetic interaction with other white oak species in western North America? 4) Is there morphological or genetic evidence to support the three described varieties of Garry oak? I obtained samples of Garry oak from 117 localities over its geographic range, as well as samples of two other California white oaks (Q. lobata and Q. douglasii) and a Rocky Mountain species (Q. gambelii). Analyses of DNA sequence data from four plastid DNA regions revealed 24 distinct molecular variants (haplotypes) in Garry oak. These show a strong south-to-north decrease in genetic diversity, consistent with post-glacial northward expansion. Haplotypes present in the northern part of the range provide evidence of two separate northward migrations, only one of which reached the northern range limit of Garry oak in BC. I found that Garry oak shared plastid DNA haplotypes with two other white oak species, indicating that it hybridizes with other oaks in the southern part of its range. The nuclear ribosomal ITS phylogeny showed poor resolution, but both cpDNA and nrDNA may indicate that Q. garryana is more closely related to the white oaks of central North America than was previously thought. My findings also suggest that the three currently recognized varieties of Garry oak (var. garryana, breweri and semota) are not well differentiated genetically, but show morphological variation at the regional level. This study shows the phylogeographic patterns within Q. garryana. In addition, it contributes to conservation efforts in Garry oak ecosystems by indicating regions of high genetic diversity in Garry oak, including genetically unique populations that may be especially worthy of preservation. / Graduate

Os percevejos barriga-verde (Dichelops spp.) (Hemiptera: Heteroptera: Pentatomidae) são considerados pragas emergentes em diferentes plantas cultivadas no Brasil. Dichelops furcatus (Fabricius) e Dichelops melacanthus (Dallas) são morfologicamente semelhantes, e os caracteres morfológicos são extremamente variáveis entre as espécies, trazendo em questão a delimitação e padrão de distribuição geográfico das mesmas. Baseado em ampla amostragem ao longo da distribuição de Dichelops spp., os objetivos gerais deste estudo foram: 1) estudar a diversidade morfológica de D. furcatus e D. melacanthus utilizando morfometria linear e geométrica; 2) definir ferramentas para a identificação das espécies reconhecidas a partir de dados morfológicos quantitativos; 3) a partir de ferramentas moleculares, testar a delimitação das espécies, estudar a diversidade e estruturação genética, e o padrão de distribuição geográfico das populações de D. furcatus e D. melacanthus no Brasil. Para isso, foram fotografadas as principais estruturas diagnósticas da morfologia geral (cabeça, pronoto e escutelo) dos indivíduos das populações estudadas e os dados de morfometria linear e geométrica analisados estatisticamente. DNA de indivíduos das duas espécies de diferentes populações do Brasil foi extraído, e dois genes mitocondriais (COI e 16s) foram amplificados por PCR e sequenciados. Resultados de morfometria geométrica mostraram grande sobreposição na forma entre as espécies, tornando esse método ineficiente na delimitação de D. furcatus e D. melacanthus. A morfometria linear foi eficiente em delimitar D. furcatus e D. melacanthus. Os resultados de diversidade e estruturação mostraram alta diversidade genética e alta estruturação genética entre as populações de ambas as espécies, suportando a existência de duas linhagens de D. furcatus e duas linhagens de D. melacanthus. / The green-belly stink bugs Dichelops spp. (Hemiptera: Heteroptera: Pentatomidae) are considered emergent pests in different cultivated plants in Brazil. Dichelops furcatus (Fabricius) and Dichelops melacanthus (Dallas) are morphologically similar, and the morphological characteristics are variable within the species, sometimes overlapping between them, bringing into question the species delimitation. Based on wide sampling throughout the whole distribution of Dichelops spp., the goals of this study were: 1) to study the morphological diversity of D. furcatus e D. melacanthus using both traditional and geometric morphometrics, and 2) define tools for the species identification recognized from quantitative morphological data; 3) to study the genetic diversity, population structuring, and the geographical distribution pattern of D. furcatus and D. melacanthus populations in Brazil using molecular data. For that, digital photographs of the main morphological structures (head, pronotum and scutellum) were taken and statistical analysis of traditional and geometric morphometrics were made. DNA from individuals of both species from different populations of Brazil was extracted, and two mitochondrial genes (COI and 16s) were amplified by PCR and sequenced. Results from geometric morphometrics show that shape of pronotum, head and scutellum were strongly overlapping between species, making this method inefficient in separating D. furcatus from D. melacanthus. However, traditional morphometrics was efficient in separating the species. Results showed high genetic diversity and high genetic structuring between populations of both species, supporting the existance of two lineages for D. furcatus and two lineages for D. melacanthus.

O contato pretérito Amazônia-Mata Atlântica vem sendo recorrentemente citado na literatura para diversos grupos da fauna Neotropical e teria ocorrido por diferentes rotas geográficas e períodos temporais. Segundo esta hipótese, em períodos quentes e úmidos as florestas se expandiram provocando retração/fragmentação das áreas abertas, ao passo que em períodos frios e secos, o inverso ocorreria. Assim, utilizando-se de crotalíneos como modelo, esta tese pretende: (1) testar o pretérito contato Amazônia-Mata Atlântica, assim como o tempo de separação entre as linhagens relictuais nesses ambientes florestados, elucidando a história demográfica das espécies de Bothrops do grupo jararacuçu, do grupo atrox e de B. bilineatus; (2) paralelamente Crotalus durissus, espécie associada à diagonal de áreas abertas da América do Sul (Caatinga, Cerrado e Chaco), foi utilizada para testar a ocorrência de expansão desses ambientes, o que levaria a quebra da hipotetizada ponte florestada Amazônia-Mata Atlântica. Através de dataset multi-locus sob Inferência Bayesiana (quatro genes mitocondriais e cinco nucleares) foram testadas as relações filogenéticas e filogeográficas entre as amostras em Bothrops e Crotalus. Cenários históricos alternativos foram testados com base em simulações coalescentes e ABC (approximate Bayesian computation). Adicionalmente, foi empregado teste de delimitação de linhagens evolutivas para o reconhecimento da diversidade, a nível de espécie, em cada grupo estudado, usando a implementação Bayesiana do algoritimo Generalized Mixed Yule-Coalescent. Os resultados filogenéticos e análises de delimitação de espécies indicam diversidade críptica para os grupos jararacussu, atrox e taeniatus. Os testes de cenários históricos sugerem (1) múltiplas conexões florestais Amazônia-Mata Atlântica nos últimos 2.5 milhões de anos, com intercâmbio faunístico em ambas as direções e (2) expansão das áreas abertas do Cerrado e Caatinga em sincronia temporal com perda de conectividade florestal Amazônia-Mata Atlântica durante o Pleistoceno tardio (3) que a formação e estabilização do Rio Amazonas teve influência na diversificação do grupo jararacuçu, gerando diversidade. Os resultados trazem informações sobre o dinamismo histórico das paisagens florestadas e abertas no Neotrópico ao longo do tempo, assim como o papel dos rios amazônicos na diversificação da fauna. Adicionalmente, os resultados apontam para instabilidade taxonômica e diversidade críptica em diversos grupos em Bothrops e em Crotalus durissus, revelando a necessidade do aprofundamento sistemático para essas serpentes venenosas de importância médica / The hypotetized historical contact Amazon-Atlantic Forest has been recurrently cited in the literature for several groups of Neotropical fauna and would have occurred by different geographic routes and time periods. According to this hypothesis, in hot and humid periods the forests expanded causing retraction / fragmentation of the open areas, while in cold and dry periods, the reverse would occur. Thus, by using Neotropical pit vipers as a model, this thesis aims to: (1) test the historical forest contact Amazon-Atlantic Forest, as well as the time of separation between relict lineages in these forested environments, elucidating the demographic history of Bothrops species from jararacussu group, atrox group and B. bilineatus; (2) Crotalus durissus, a species associated with the diagonal of open areas of South America (Caatinga, Cerrado and Chaco), was used in parallel to test the occurrence of expansion of these environments, which would lead to the breakage of the hypothetical Amazon-Atlantic Forest forested bridge. Phylogenetic and phylogeographic relationships between samples of Bothrops and Crotalus were tested through a multi-locus dataset (four mitochondrial genes and five nuclear) under Bayesian Inference. Alternative historical scenarios were tested based on coalescent simulations and ABC (approximate Bayesian computation). In addition, was inferred independently evolving lineages to recognized species diversity in each group studied, using Bayesian implementation of the molecular species delimitation algorithm Generalized Mixed Yule-Coalescent. Phylogenetic results and analyzes of species delimitation indicate cryptic diversity for the groups jararacussu, atrox and taeniatus. The tests of historical scenarios suggest (1) multiple Amazon-Atlantic Forest forest connections in the last 2.5 million years, with faunal exchange in both directions and (2) expansion of the open areas of the Cerrado and Caatinga in temporal synchrony with loss of forest bridge Amazon-Atlantic Forest during late Pleistocene (3) that the formation and stabilization of the Amazon River influenced the diversification of the jararacussu group, generating diversity. The results provide information on the historical dynamism of forested and open landscapes in the Neotropics over time, as well as the role of Amazonian rivers in the diversification of fauna. Moreover, the results point to taxonomic instability and cryptic diversity in several groups within Brothrops and Crotalus durissus, revealing the need for systematic deepening for these medically important venemous snakes

<p>Ovom tezom je obuhvaćena analiza genetičke strukture i filogeografskog položaja vuka (<em>Canis lupus L. </em>1758) na teritoriji Bosne i Hercegovine, na uzorku od ukupno 79 jedinki. Analize su sprovedene primjenom (i) 18 mikrosatelitskih lokusa nDNK pomoću kojih su detektovani: nivo genetičke varijabilnosti, populaciona struktura, prolazak populacije kroz genetičko usko grlo, te ukr&scaron;tanje u srodstvu, i (ii) kontrolnog&nbsp; regiona&nbsp; (CR)&nbsp; regiona&nbsp; mtDNK&nbsp; pomoću&nbsp; kojih&nbsp; su sprovedene filogeografske analize.&nbsp; U&nbsp; radu&nbsp; je&nbsp; uočeno&nbsp; je&nbsp; grupisanje&nbsp; jedinki&nbsp; vuka&nbsp; Bosne&nbsp; i Hercegovine&nbsp; u&nbsp; dva&nbsp; genetička&nbsp; klastera&nbsp; &scaron;to,&nbsp; s&nbsp; obzirom&nbsp; na&nbsp; slabu&nbsp; statističku&nbsp; podržanost, najvjerovatnije&nbsp; ukazuje&nbsp; na&nbsp; prisustvo&nbsp; strukture&nbsp; na&nbsp; većem&nbsp; nivou.&nbsp; Prethodno&nbsp; navedeno&nbsp; je detektovano analizama populacione strukture dijela dinarsko - balkanske populacije vuka,gdje je uočena distribucija vukova Bosne i Hercegovine i Srbije u odvojene genetičke klastere. Statistički značajni signali prolaska populacije vuka Bosne i Hercegovine kroz genetičko usko grlo u skorijoj pro&scaron;losti nisu detektovani. Sekvence kontrolnog regiona mtDNK vuka pokazale su se dovoljno informativnim za detekciju jedinstvenih haplotipova vuka Bosne i Hercegovine, za&nbsp; koje&nbsp; je&nbsp; uočena&nbsp; distribucija&nbsp; u&nbsp; dvije,&nbsp; prethodno&nbsp; u&nbsp; literaturi, detektovane haplogrupe bez jasnog alopatrijskog obrasca. Pored toga, analizama sekvenci dijela kontrolnog regiona mtDNK&nbsp; uzorka&nbsp; vuka&nbsp; Evrope,&nbsp; uočeno&nbsp; je da se demografska ekspanzija haplogrupe 2 desila mnogo ranije u pro&scaron;losti u odnosu na period ekspanzije haplogrupe 1, koji se poklapa sa periodom razdvajanja navedenih haplogrupa, prije oko 13000 godina, &scaron;to ukazuje da je posljednji glacijalni maksimum imao uticaja u oblikovanju strukture genetičkih linija vuka u pro&scaron;losti. Rezultati dobijeni u ovom istraživanju su veoma informativni u cilju uspostavljanja pravilnog menadžmenta vrste i kreiranja plana za&scaron;tite vuka na nivou Bosne i Hercegovine, odnosno, na nivou dinarsko - balkanske populacije vuka iz koje se vr&scaron;e rekolonizacije jedinki u susjedne populacije.</p> / <p>In this thesis, the genetic structure and phylogeography of the wolf (Canis L. 1758) in the territory of Bosnia and Hercegovina were analysed, from a total sample of 79 individuals. Analyses were conducted by applying (i) 18 microsatellite loci of nuclear DNA, by which we estimated: the level of genetic&nbsp; variability, population structure, kinship, bottleneck and inbreeding, and (ii) control region of mtDNA by which we analysed phylogeography. Two genetic clusters were observed for the wolf population&nbsp; from Bosnia and Hercegovina, although with statistically low support, which may point to structuring at the higher level. Indeed, after analysing the population structure at the higher, Dinaric - Balkan level, the distribution of wolves&nbsp; from Bosnia and Hercegovina and&nbsp; Serbia was observed as falling into two distinct genetic clusters. Statistically significant signs of the recent bottleneck were not observed in the wolf&nbsp; population from Bosnia and Hercegovina. Analyses of control region mtDNA were conducted with the aim of detecting haplotypes in the Bosnia and Hercegovina population, as well as in the European&nbsp; samples. Distribution of&nbsp; haplotypes into two haplogroups, described in previous literature, was&nbsp; observed, without a clear alopatric phylogeny pattern. Furthermore, the analyses of the same&nbsp; molecular marker showed that demographic expansion of haplogroup 2 occurred significantly earlier when compared to the demographic explosion of haplogroup 1 . Results from this study are extremely&nbsp; important for the creation of a management plan for wolves from Bosnia and Hercegovina, and at the higher Dinaric - Balkan level.</p>

Dendrocolaptes platyrostris é uma espécie de ave florestal associada às matas de galeria do corredor de vegetação aberta da América do sul (D. p. intermedius) e à Floresta Atlântica (D. p. platyrostris). Em um trabalho anterior, foi observada estrutura genética populacional associada às subespécies, além de dois clados dentro da Floresta Atlântica e evidências de expansão na população do sul, o que é compatível com o modelo Carnaval-Moritz. Utilizando approximate Bayesian computation, o presente trabalho avaliou a diversidade genética de dois marcadores nucleares e um marcador mitocondrial dessa espécie com o objetivo de comparar os resultados obtidos anteriormente com os obtidos utilizando uma estratégia multi-locus e considerando variação coalescente. Os resultados obtidos sugerem uma relação de politomia entre as populações que se separaram durante o último período interglacial, mas expandiram após o último máximo glacial. Este resultado é consistente com o modelo de Carnaval-Moritz, o qual sugere que as populações sofreram alterações demográficas devido às alterações climáticas ocorridas nestes períodos. Trabalhos futuros incluindo outros marcadores e modelos que incluam estabilidade em algumas populações e expansão em outras são necessários para avaliar o presente resultado / Dendrocolaptes platyrostris is a forest specialist bird associated to gallery forests of the open vegetation corridor of South America (D. p. intermedius) and to the Atlantic forest (D. p. platyrostris). A previous study showed a population genetic structure associated with the subspecies, two clades within the Atlantic forest, and evidence of population expansion in the south, which is compatible with Carnaval- Moritz\'s model. The present study evaluated the genetic diversity of two nuclear and one mitochondrial markers of this species using approximate Bayesian computation, in order to compare the results previously obtained with those based on a multi-locus strategy and considering the coalescent variation. The results suggest a polytomic relationship among the populations that split during the last interglacial period and expanded after the last glacial maximum. This result is consistent with the model of Carnaval-Moritz, which suggests that populations have undergone demographic changes due to climatic changes that occurred in these periods. Future studies including other markers and models that include stability in some populations and expansion in others are needed to evaluate the present result

A delimitação de espécies é essencial para a caracterização e conservação da biodiversidade. No entanto, representa um desafio para grupos onde há pouca variação em morfologia, como no caso dos lagartos Iphisini. São conhecidas oito espécies pertencentes a seis gêneros na tribo, com base em análises moleculares e de anatomia hemipeniana foram detectadas quatro espécies candidatas para Iphisa. A tribo filogeneticamente aparentada Gymnophthalmini apresenta maior riqueza de espécies e diversidade morfológica, principalmente em espécies com adaptações para a vida fossorial. No entanto, ainda se conhece pouco sobre os mecanismos históricos e ecológicos que causam distintos padrões de especiação, apesar de historicamente o papel de isolamento geográfico ter sido enfatizado para a biota Neotropical. Em tempos recentes, foram desenvolvidos métodos quantitativos para abordar questões evolutivas como probabilidades de especiação, variações em taxas de diversificação e reconstrução de demografia histórica de populações e migração. Implementei neste estudo uma combinação de métodos quantitativos com uso de dados moleculares, morfológicos e ambientais para testar as hipóteses que: há diversidade não reconhecida em Iphisini; as diferenças em riqueza e disparidade morfológica entre Iphisini e outras tribos de Gymnophthalminae se deve a diferenças em tempo e modo de diversificação, e que a diversificação em Acratosaura ocorreu por isolamento geográfico causado por flutuações paleoclimáticas. Com base em análises moleculares, foram delimitadas quatro espécies candidatas para Iphisini, aumentando em 33% a diversidade conhecida para a tribo. Não houve variação entre as espécies candidatas de Acratosaura em morfometria. A filogenia estimada para Gymnophthalminae apresentou alto suporte para a relação entre Iphisini e Heterodactylini, e demonstra um tempo de diversificação e riqueza neste clado similar a Gymnophthalmini. As tribos apresentaram padrões de diversificação semelhantes, mas taxas distintas. Os padrões de evolução morfológica foram congruentes com a diversificação em Gymnophthalmini, porém distintas em Heterodactylini sensu lato, indicando que disparidade independe de diversificação. As análises filogeográficas indicam que as populações de Acratosaura apresentaram estabilidade demográfica e espacial ao longo do tempo, com evidências de fluxo gênico entre linhagens diferenciadas. Desta forma, os resultados sugerem que Acratosaura diversificou sem influência de variações históricas no clima, e provavelmente sem isolamento reprodutivo completo / Species delimitation is essential for characterization and conservation of biodiversity. Nevertheless, it represents a challenge for groups in which morphological variation is subtle, such as the microteiid lizards of the tribe Iphisini. Eight species from six genera are currently recognized in the tribe but recently, based on molecular analysis and hemipenial anatomy, four candidate species were inferred for Iphisa. The phylogenetically related tribe Gymnophthalmini presents higher species richness and morphological diversity, specially in forms with adaptations to fossoriality. Nevertheless, the historical and ecological mechanisms involved in the distinct speciation patterns are poorly known, although geographical isolation have been historically emphasized for neotropical biota. In recent times, quantitative methods were developed to address evolutionary questions such as speciation probabilities, variation in diversification rates and reconstruction of historical demography of populations and migration. In this study I used a combination of quantitative methods based on molecular, morphological and environmental data for testing the hypothesis that: there is unrecognized diversity within Iphisini; differences in species richness and disparity among Iphisini and related tribes are congruent with differences in time and mode of diversification; and that diversification in Acratosaura occurred with geographical isolation caused by paleoclimatic fluctuations. Based on the results of molecular analyses, four candidate species were delimited for Iphisini, rising in 33% the tribe diversity. There was no significant variation in morphometry between candidate species of Acratosaura. The phylogeny of Gymnophthalminae presented high support for the relationship between Iphisini and Heterodactylini, and showed diversification timming and species richness comparable between this clade and Gymnophthalmini. The tribes presented similar diversification patterns but distinct rates. The patterns of morphological evolution were congruent with diversification patterns in Gymnophthalmini but distinct in Heterodactylini sensu lato, indicating that disparity is independent from diversification in the group. The phylogeographic analyses indicate that populations of Acratosaura presented demographic and spatial stability through time, with evidences of gene flow among lineages after differentiation. Thus, the results suggest that diversification of Acratosaura was not influenced by variations in historical climate, and probably occurred without complete reproductive isolation

Espécies de medusozoários com ciclos de vida muito diferentes habitam distintos mares e oceanos ao redor do mundo. Em uma escala regional, algumas espécies de hidrozoários estão amplamente distribuídas no Atlântico Sul-ocidental, (litorais do Brasil e Argentina), com populações habitando ambientes heterogêneos e estruturados. A relação entre a distribuição das espécies e a maior parte dos fatores ambientais é pouco conhecida. Deste modo, o objetivo de nosso estudo é pesquisar os padrões de distribuição e a estrutura genética populacional de duas espécies de hidrozoários do Atlântico Sul-ocidental em relação a: (1) as diferentes histórias naturais e (2) as distintas estruturas de massas d\'água do ambiente marinho. As espécies estudadas foram Olindias sambaquiensis (meroplanctônica, ciclo de vida: ovo &#8882; plânula &#8882; pólipo &#8882; medusa &#8882; ovo) e Liriope tetraphylla (holoplanctônica, ciclo de vida: ovo &#8882; plânula &#8882; medusa &#8882; ovo). Dados sobre a ecologia e história natural de tais espécies foram coletados e análises filogeográficas foram conduzidas utilizando os marcadores mitocondriais 16S e CO1. Nossos resultados revelaram um padrão filogeográfico similar para ambas as espécies. As populações brasileiras são basais e têm uma maior diversidade nucleotídica que as populações argentinas, as quais ocupam uma posição apical. O Rio da Prata não é uma barreira efetiva e introgressão possivelmente ocorre em ambas as espécies, podendo estar relacionada à circulação das massas d\'água. A estrutura genética encontrada para Olindias sambaquiensis pode estar relacionada com seu hábito demersal e afinidade com massas d\'água costeiras, e para Liriope tetraphylla com seu ciclo reprodutivo e auto-recrutamento. / Medusozoan species, with quite different life-cycles, inhabit different seas and oceans around the world. In a regional scale, some hydrozoan species are widespread along the Southwestern Atlantic Ocean (Brazilian and Argentinean shores), with populations distributed along a heterogeneous and structured environment. The relation between the distribution of the species and most of the biological and environmental factors is still largely unknown. Therefore, the aim of this study is to investigate the distributional patterns and genetic structure of populations of two hydrozoan species of SW Atlantic Ocean in relation to: (1) the different life histories and (2) the water masses structures of the marine environment. The species studied were the meroplanktonic Olindias sambaquiensis (life cycle: egg &#8882; planula &#8882; polyp &#8882; medusa &#8882; egg) and the holoplanktonic Liriope tetraphylla (life cycle: egg &#8882; planula &#8882; medusa &#8882; egg). We gathered data on the ecology and natural history of the species, and carried out phylogeographic analyses using CO1 and 16S DNA markers. Our results have shown similar phylogeographical patterns and genetic structures for both species. The Brazilian populations are basal and have a higher nucleotidic diversity than the apical Argentinean populations. The Rio de La Plata river is not an effective barrier, and introgression possibly occurs for both species and might be related to the circulation of the water masses. Biologically, the genetic structure found for Olindias sambaquiensis must be related to its demersal habit and close affinity to coastal water masses, and that found for Liriope tetraphylla must be related to its reproductive cycle and auto-recruitment.