New Zealand is a continental island surrounded by deep-ocean, with a complex system of currents and oceanographic anomalies that may serve to isolate populations of coastal marine organisms. In particular Cook Strait is a 26 km wide body of water separating the North and South Islands which is characterised by complex interactions of tides and converging water masses. Cook Strait is a geologically recent formation that may also impart an historical influence on the biogeographic distribution of coastal marine taxa. In order to investigate the phylogeographic structure of coastal marine taxa around New Zealand's coastline and to investigate the processes that may contribute toward this genetic structure, I analysed mitochondrial DNA genes from limpet species of the Cellana genus. Phylogenetic analyses of the ribosomal 12S and 16S DNA genes showed that C. ornata may approximate the founding lineage to New Zealand, but these genes were unable to resolve between contrasting biogeographic hypotheses about the origin of Cellana in New Zealand. Intraspecific analyses of the mitochondrial cytochrome b gene from populations throughout the biogeographic range of Cellana ornata, C. radians and C. flava showed concordant genetic discontinuity at Cook Strait. Further analyses suggest that allopatric fragmentation and restricted gene flow have caused significant genetic differentiation between populations of the North and South Island. Demographic expansion was also identified for C. radians. The influence of contemporary nearshore currents and sea surface temperature was assessed using the mitochondrial cytochrome b gene for C. radians and C. ornata. Low levels of genetic differentiation between populations corresponding to 'current-zones' suggests that contemporary oceanic processes may be contributing to the genetic pattern observed for these species. However, the shallow divergence between haplotypes and populations restricted thorough investigation of contemporary gene flow. Genealogical concordance across co-distributed marine taxa of New Zealand also lends support to the historic association of genetic and species discontinuities with recent geological changes, such as sea level fluctuations.

New Zealand is a continental island surrounded by deep-ocean, with a complex system of currents and oceanographic anomalies that may serve to isolate populations of coastal marine organisms. In particular Cook Strait is a 26 km wide body of water separating the North and South Islands which is characterised by complex interactions of tides and converging water masses. Cook Strait is a geologically recent formation that may also impart an historical influence on the biogeographic distribution of coastal marine taxa. In order to investigate the phylogeographic structure of coastal marine taxa around New Zealand's coastline and to investigate the processes that may contribute toward this genetic structure, I analysed mitochondrial DNA genes from limpet species of the Cellana genus. Phylogenetic analyses of the ribosomal 12S and 16S DNA genes showed that C. ornata may approximate the founding lineage to New Zealand, but these genes were unable to resolve between contrasting biogeographic hypotheses about the origin of Cellana in New Zealand. Intraspecific analyses of the mitochondrial cytochrome b gene from populations throughout the biogeographic range of Cellana ornata, C. radians and C. flava showed concordant genetic discontinuity at Cook Strait. Further analyses suggest that allopatric fragmentation and restricted gene flow have caused significant genetic differentiation between populations of the North and South Island. Demographic expansion was also identified for C. radians. The influence of contemporary nearshore currents and sea surface temperature was assessed using the mitochondrial cytochrome b gene for C. radians and C. ornata. Low levels of genetic differentiation between populations corresponding to 'current-zones' suggests that contemporary oceanic processes may be contributing to the genetic pattern observed for these species. However, the shallow divergence between haplotypes and populations restricted thorough investigation of contemporary gene flow. Genealogical concordance across co-distributed marine taxa of New Zealand also lends support to the historic association of genetic and species discontinuities with recent geological changes, such as sea level fluctuations.

A costa austral da América do Sul (CAAS) e o oceano Austral (OA) possuem grande variedade de habitats e estão historicamente conectados desde a abertura da passagem de Drake. A fauna marinha de ambas as regiões é altamente diversa e muitas espécies possuem distribuições geográficas contraditórias, como é o caso dos hidroides bentônicos (Cnidaria, Hydrozoa). Toda essa heterogeneidade faunística atrai estudos adicionais em biogeografia, envolvendo a busca por áreas de endemismo e outros padrões de distribuição geográfica. Uma atualização do status taxonômico das espécies de hidroides bentônicos da CAAS e OA foi feito, reunindo informações sobre sua riqueza, grau de endemismo, substrato biológico e distribuição geográfica. Um total de 5.621 amostras e 359 morfoespécies de hidroides bentônicos foram levantadas para a área de estudo e checadas taxonomicamente, sendo 256 identificadas até o nível específico. Os registros de presença e ausência ao longo da área foram usados em uma análise de similaridade pelo índice de Bray-Curtis, sendo os resultados sintetizados em \"clusters\" hierárquicos e nMDS. A taxa de endemismo para ambos a CAAS e OA foi de 54%, sendo o OA responsável por 88% dos registros de espécies endêmicas. As espécies de leptotecados foram as que apresentaram maior amplitude de distribuição horizontal e vertical. A maior parte das espécies de hidroides bentônicos levantadas são substrato-generalistas. Treze assembleias ecológicas de hidroides bentônicos foram encontradas ao longo da CAAS e OA, as quais foram relacionadas com a dinâmica oceanográfica da área e comparadas com ecorregiões, realms, assembleias e áreas de endemismo previamente delimitadas para a região. As áreas de endemismo para a CAAS e OA foram hipotetizadas por meio da Análise de Endemicidade (AE) em uma otimização pelo software NDM-VNDM, com uma grade de 10° latitude X 10° longitude. Nove (F=0.5) e 10 (F=1.0) áreas consensuais de endemismo foram historicamente relacionadas com o isolamento da Antártica e comparadas com hipóteses já existentes para a CAAS e OA. Todas as áreas foram discutidas considerando-se os processos de vicariância e dispersão, e com relação ao real grau de endemicidade que elas representam. Uma PAE também foi realizada mas apenas com 61 espécies de hidroides bentônicos endêmicos da região acima de 45°S. Essa análise foi feita com o objetivo de reanalisar os dados previamente publicados por Marques & Peña Cantero (2010), inserindo um conjunto de dados complementar para a obtenção de uma melhor definição e acurácia nas áreas de endemismo delimitadas para a região. Oito áreas de endemismo foram definidas como subregiões dos padrões previamente encontrados. O uso de diferentes técnicas e conjuntos de dados biogeográficos são meios alternativos para clarear padrões gerais de áreas de endemismo e também outros padrões relacionados à comunidades ecológicas e estudos em conservação da biodiversidade / The southern South America (SSA) coast and the Southern Ocean (SO) have a high differentiation of habitats and are historically connected since the opening of the Drake Passage. The marine fauna of both regions are connected, highly diverse and many species are contradictory distributed, such as the benthic hydroids (Cnidaria, Hydrozoa). All this faunistic heterogeneity calls attention for additional biogeographic investigations, involving the search for areas of endemism and other geographic distribution patterns. An update of the taxonomic status of the species of benthic hydroids from SSA and SO was carried out, gathering information about their richness, endemicity level, biological substrates and geographic distribution. A total of 5.621 samples and 359 morphospecies of benthic hydroids were surveyed for the studied area and taxonomically checked, being 256 identified up to the specific level. The records of presence-absence along the SSA and SO were used in a Bray-Curtis similarity analysis and the results were synthesized in hierarchical clusters and nMDS. The level of endemism at both the SSA and the SO is 54%, being the SO responsible for 88% of the records of endemic species. Leptothecate species had the widest horizontal and vertical distribution and most part of the benthic hydroids surveyed were considered substrate-generalists. Thirteen ecological assemblages of benthic hydroids were found along the SSA and SO and compared with the oceanographic dynamics of the area, as well as with earlier ecoregions, realms, assemblages, and areas of endemism delimited for the region. Areas of endemism were hypothesized for the SSA and SO using the Endemicity Analysis (EA) through an optimization performed by the software NDM-VNDM, with a 10° latitude X 10° longitude grid. Nine (F=0.5) and 10 (F=1.0) consensus areas of endemism were historically related with the isolation of Antarctica, and compared with previous hypotheses for the SSA and SO. All areas were discussed in the context of vicariance/dispersal processes, and concerning the real degree of endemicity that they represent. PAE was also performed but only with 61 endemic species of benthic hydroids for the region above the 45°S. This analysis was carried out with the aim to reanalyze previous data already published by Marques & Peña Cantero (2010), inserting a complementary dataset in order to obtain a better definition and accuracy in the areas of endemism delimited for the region. Eight areas of endemism were defined as subregions of the patterns previously found. The use of different techniques and biogeographic datasets are alternative strategies to clarify general patterns of areas of endemism, as well as other patterns related with ecological communities and studies in conservation biology

A costa austral da América do Sul (CAAS) e o oceano Austral (OA) possuem grande variedade de habitats e estão historicamente conectados desde a abertura da passagem de Drake. A fauna marinha de ambas as regiões é altamente diversa e muitas espécies possuem distribuições geográficas contraditórias, como é o caso dos hidroides bentônicos (Cnidaria, Hydrozoa). Toda essa heterogeneidade faunística atrai estudos adicionais em biogeografia, envolvendo a busca por áreas de endemismo e outros padrões de distribuição geográfica. Uma atualização do status taxonômico das espécies de hidroides bentônicos da CAAS e OA foi feito, reunindo informações sobre sua riqueza, grau de endemismo, substrato biológico e distribuição geográfica. Um total de 5.621 amostras e 359 morfoespécies de hidroides bentônicos foram levantadas para a área de estudo e checadas taxonomicamente, sendo 256 identificadas até o nível específico. Os registros de presença e ausência ao longo da área foram usados em uma análise de similaridade pelo índice de Bray-Curtis, sendo os resultados sintetizados em \"clusters\" hierárquicos e nMDS. A taxa de endemismo para ambos a CAAS e OA foi de 54%, sendo o OA responsável por 88% dos registros de espécies endêmicas. As espécies de leptotecados foram as que apresentaram maior amplitude de distribuição horizontal e vertical. A maior parte das espécies de hidroides bentônicos levantadas são substrato-generalistas. Treze assembleias ecológicas de hidroides bentônicos foram encontradas ao longo da CAAS e OA, as quais foram relacionadas com a dinâmica oceanográfica da área e comparadas com ecorregiões, realms, assembleias e áreas de endemismo previamente delimitadas para a região. As áreas de endemismo para a CAAS e OA foram hipotetizadas por meio da Análise de Endemicidade (AE) em uma otimização pelo software NDM-VNDM, com uma grade de 10° latitude X 10° longitude. Nove (F=0.5) e 10 (F=1.0) áreas consensuais de endemismo foram historicamente relacionadas com o isolamento da Antártica e comparadas com hipóteses já existentes para a CAAS e OA. Todas as áreas foram discutidas considerando-se os processos de vicariância e dispersão, e com relação ao real grau de endemicidade que elas representam. Uma PAE também foi realizada mas apenas com 61 espécies de hidroides bentônicos endêmicos da região acima de 45°S. Essa análise foi feita com o objetivo de reanalisar os dados previamente publicados por Marques & Peña Cantero (2010), inserindo um conjunto de dados complementar para a obtenção de uma melhor definição e acurácia nas áreas de endemismo delimitadas para a região. Oito áreas de endemismo foram definidas como subregiões dos padrões previamente encontrados. O uso de diferentes técnicas e conjuntos de dados biogeográficos são meios alternativos para clarear padrões gerais de áreas de endemismo e também outros padrões relacionados à comunidades ecológicas e estudos em conservação da biodiversidade / The southern South America (SSA) coast and the Southern Ocean (SO) have a high differentiation of habitats and are historically connected since the opening of the Drake Passage. The marine fauna of both regions are connected, highly diverse and many species are contradictory distributed, such as the benthic hydroids (Cnidaria, Hydrozoa). All this faunistic heterogeneity calls attention for additional biogeographic investigations, involving the search for areas of endemism and other geographic distribution patterns. An update of the taxonomic status of the species of benthic hydroids from SSA and SO was carried out, gathering information about their richness, endemicity level, biological substrates and geographic distribution. A total of 5.621 samples and 359 morphospecies of benthic hydroids were surveyed for the studied area and taxonomically checked, being 256 identified up to the specific level. The records of presence-absence along the SSA and SO were used in a Bray-Curtis similarity analysis and the results were synthesized in hierarchical clusters and nMDS. The level of endemism at both the SSA and the SO is 54%, being the SO responsible for 88% of the records of endemic species. Leptothecate species had the widest horizontal and vertical distribution and most part of the benthic hydroids surveyed were considered substrate-generalists. Thirteen ecological assemblages of benthic hydroids were found along the SSA and SO and compared with the oceanographic dynamics of the area, as well as with earlier ecoregions, realms, assemblages, and areas of endemism delimited for the region. Areas of endemism were hypothesized for the SSA and SO using the Endemicity Analysis (EA) through an optimization performed by the software NDM-VNDM, with a 10° latitude X 10° longitude grid. Nine (F=0.5) and 10 (F=1.0) consensus areas of endemism were historically related with the isolation of Antarctica, and compared with previous hypotheses for the SSA and SO. All areas were discussed in the context of vicariance/dispersal processes, and concerning the real degree of endemicity that they represent. PAE was also performed but only with 61 endemic species of benthic hydroids for the region above the 45°S. This analysis was carried out with the aim to reanalyze previous data already published by Marques & Peña Cantero (2010), inserting a complementary dataset in order to obtain a better definition and accuracy in the areas of endemism delimited for the region. Eight areas of endemism were defined as subregions of the patterns previously found. The use of different techniques and biogeographic datasets are alternative strategies to clarify general patterns of areas of endemism, as well as other patterns related with ecological communities and studies in conservation biology