Despite over four decades of research on deep-sea hydrothermal vent ecosystems, major gaps remain in our understanding of these systems. Knowledge of microeukaryote diversity, abundance, and involvement in ecosystem function lags far behind that of prokaryotes, and contributions of the non-endosymbiotic microbiome in faunal assemblages to ecosystem processes and overall hydrothermal vent microbial diversity are not known. This research addresses these gaps using high-throughput sequencing of 16S/18S rRNA genes and metagenomes from vent and surrounding non-vent habitats encompassing diffuse hydrothermal fluids, plumes, deep seawater, and microbes in assemblages of the foundation tubeworm species Ridgeia piscesae. Co-occurrence/covariance is a central method used, first, between prokaryotes with known extreme habitat preferences and microeukaryotes to infer potential endemism in the latter, and then between microbes and fauna in R. piscesae assemblages to infer interspecies interactions. Microeukaryote distribution and abundance suggest potential vent endemic microeukarya are infrequently encountered, potentially in low abundance, and belong to novel lineages of Rhizaria and Stramenopila. Potential endemism is inferred for relatives of known apusomonads, excavates, and some clades of Syndiniales. R. piscesae assemblages are shown to be hotspots of microbial taxonomic richness and exhibit a robust temperature-driven distinction in assemblage composition above and below ~25°C spanning micro, meio and macro size classes and microbial domains (Bacteria, Archaea, and micro-Eukarya). Likely interacting faunal and microbial taxa among R. piscesae assemblages are identified as ‘core communities’, which included eight macro- and meiofaunal taxa and members of the Bacteroidetes and Epsilonbacteraeota in highT communities (>25°C) and more meiofaunal species in addition to Alpha- and Gammaproteobacteria, and Actinobacteria in lowT communities (<25°C). Core communities were used to guide metagenomic investigations of microbial functional potential. Exploratory metagenomic analysis required development of new methods to deal with compositional data. ‘Enrichment leanings’ were developed to prioritize in-depth functional comparisons between sample types, which revealed clades within core community microbes with differing functional potential between highT and lowT assemblages and between assemblages and fluids. The balance of autotrophy-heterotrophy genes and patterns of genes for different carbon, nitrogen, and sulfur-cycling processes were tested as potential metrics of community-level function but did not distinguish assemblages by highT/lowT designations. This research brings us closer to understanding hydrothermal vent ecosystem function and suggests sizeable continued discovery potential. / Graduate / 2022-06-08

<p> Wet chemical neutron activation analysis procedures for Au., Pd and Ir together with a non-destructive gamma-counting procedure for Mn are described and applied to the determination of these metals in three Antarctic (E21 -17, E13-3 and E 17-10) and one Caribbean (P63 04-9) deep-sea cores. A total of 49 samples were analyzed. The average values of Au, Pd, Ir in ppb and Mn in Wt.% (together with standard deviations of the mean are: (see table in theses) No large differences exist between Au, Pd and Ir concentrations in different types of deep-sea sediments nor in cores from different areas and their values are within the general concentration range found in most crustal rocks. A general discussion of the sources of precious metals in deep-sea sediments is given. The most important precious metal source in the cores studied in this work is detrital material from land. The contribution of extraterrestrial material to the Au and Pd content of deep-sea sediments is not important but in cores with depositional rates as low as a few tenths of a mm per thousand years, extraterrestrial material may account for more than half of the total Ir content. From the non-detrital Ir content of deep-sea manganese nodules the accretion rate of extraterrestrial material over the. entire surface of the earth is calculated to be about 200 tons per day with an upper limit of 310 tons per day. The constancy of Ir content in deep-sea cores as a function of depth suggests that the influx of extraterrestrial material during the past 3 to 4 million years was probably fairly constant. </p> / Thesis / Master of Science (MSc)

<p> An assemblage of coral skeletons of the species Desmophyllum cristagalli were obtained from the top of Orphan Knoll, 550 km northeast of Newfoundland, from depths of approximately 1600 and 1800 m. The corals were observed for their macro- and micro-boring assemblages, and the boring morphologies documented, using binocular and scanning electron microscopy. Samples of coral were embedded with resin and etched for examination of the micro-boring assemblages.</p> <p> The largest volumetric amount of skeletal material removed was by sponges forming Entobia. This further corroborates the assumption that various species of boring sponges are distributed ubiquitously throughout a wide bathymetric range.</p> <p> Four distinct fungal forms were found, two tubular forms interpreted to be hyphal filaments and two bulbous forms interpreted to be sporangia. These forms were described on the basis of their shape, size, mode of branching, association with other structures and texture. They were then compared to other micro-boring assemblages found in previous studies from various bathymetric ranges. Some forms described in this study were found to be similar to forms described in other studies. Other forms in this study were not found to be documented. It is suggested, therefore, that certain forms, as well as low ichnodiversity, may indicate deeper water environments.</p> <p> Destructive micritization structures were also found in resin casts as well as in thin section. The extent of micritization may indicate the intensity of the parameters at the substrate that affect carbonate dissolution, such as CaCO3 and CO2 concentrations, pH, temperature, and salinity. It would therefore indicate the ambient water conditions at the substrate. If a sufficiently large database could be obtained, as well as distinct separation of the parameters responsible for carbonate dissolution, micritization may be used in a mapping of the carbonate compensation depth through time and depth ranges.</p> / Thesis / Bachelor of Science (BSc)

京都大学 / 新制・課程博士 / 博士(農学) / 甲第24679号 / 農博第2562号 / 新制||農||1100(附属図書館) / 学位論文||R5||N5460(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 澤山 茂樹, 教授 吉田 天士, 准教授 中川 聡 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Light regulates many biological processes through light-sensitive proteins called opsins. Opsins are involved in vision, but they are also expressed in extraretinal tissue, where their roles are far less clear. Fish have large opsin repertoires, derived from a long history of gene duplication and divergence, making them useful models to study opsin diversity and function. I introduce the deep-sea sablefish (Anoplopoma fimbria) as a model for opsin research for three main reasons: i) the availability of a draft genome and transcriptome, simplifying the characterization of this species’ opsin repertoire, ii) the proximity of the only sablefish aquaculture facility in the world, providing exclusive access to a large number of individuals at all developmental stages, iii) the observation that sablefish occupy very different light environments during the course of development, ranging from well-lit shallow waters to the aphotic zone, which provides a light environment context for opsin gene expression data. My survey of the genome showed that sablefish have 36 distinct opsin genes (7 visual and 29 non-visual), even though they spend most of their lives in the dark. The sablefish opsin sequences and repertoire are similar to those of other teleost fish. To test the hypothesis that the sablefish opsin repertoire is being expressed/transcribed during the comparatively brief period of time when this species is exposed to light (the free-swimming larval stage through to the juvenile stage), I quantified the expression of five paralogous genes from a well-studied non-visual opsin family (OPN4’s) in the brain across life stages. Data show statistically stable expression of Opn4m1 and Opn4m3 among life stages, a rough association of Opn4x1 and Opn4m2 expression with age and light environment, and little-to-no expression of Opn4x2. I localized proteins encoded by the most highly expressed class of OPN4 genes in the brain, the Opn4m genes, to the surface of the optic tectum just below a cranial ‘window’; a zone that has been shown to express dozens of opsins in zebrafish (a distant relative, with their ancestor diverging more than 230 million years ago). Thus, in some cases, expression appears to be correlated with light exposure not only temporally, but also spatially. By studying non-visual opsins in sablefish, I have challenged and broadened the current understanding of opsin evolution and function in fish and provided the foundation for future studies to test brain regions for light-sensitivity, perform opsin gene knock-outs, and explore potential light-independent processes. / Graduate / 2023-09-06

Cold-water corals act as critical foundation species in the deep sea by creating extensive three-dimensional habitat structures that support biodiversity hotspots. There is currently a paucity of data concerning the environmental requirements and physiology of cold-water corals, severely limiting our ability to predict how resilient they will be to future environmental change. Cold-water corals are expected to be particularly vulnerable to the effects of ocean acidification, the reduction in seawater pH and associated changes to the carbonate system caused by anthropogenic CO2 emissions. Here, the ecological niche and physiology of the cold-water coral Lophelia pertusa is explored to predict its sensitivity to ocean acidification. Species distribution models were generated in order to quantify L. pertusa’s niche in the Gulf of Mexico with regard to parameters including seafloor topography, the carbonate system, and the availability of hard substrate. A robust oceanographic assessment of the Gulf of Mexico was conducted in order to characterize the current environmental conditions at benthic sites, with a focus on establishing the baseline carbonate system in L. pertusa habitats. Finally, an experimental approach was used to test the physiological response of biogeographically separated L. pertusa populations from the Gulf of Mexico and the Norwegian coast to ocean acidification. Based on my findings, it appears that L. pertusa already persists near the edge of its viable niche space in some locations, and therefore may be highly vulnerable to environmental change. However, experimental results suggest that some populations may be surprisingly resilient to ocean acidification, yielding broad implications for the continued persistence of cold-water corals in future oceans. / Biology

Tesis por compendio / [ES] A lo largo de la historia, el hombre ha explotado los recursos minerales de la tierra para su supervivencia y desarrollo tecnológico sin un equilibrio con su regeneración. Dado el crecimiento de la población mundial y la reducción de recursos, el hombre comenzó a buscar nuevos depósitos que se encontraron en la década de 1960 en las profundidades de los océanos. Con estos, la humanidad empezò a pensar en extraer los minerales de estos depósitos y esto llevò al nacimiento de Deep Sea Mining (DSM). Las consecuencias de las actividades mineras en las profundidades del mar no se conocen realmente y los efectos pueden ser diferentes: contaminación acústica, contaminación lumínica, contaminación química, destrucción del hábitat, fragmentación del hábitat y pérdida de especies que son la base de muchos sistemas vitales. El impacto acústico de estas actividades puede tener importantes consecuencias en las especies marinas, aunque este es el tema más ignorado. El propósito de este proyecto de doctorado fue proporcionar una comprensión básica de los posibles impactos acústicos del DSM en la biodiversidad antes de que comiencen estas actividades. Para hacer esto, el proyecto de doctorado se organizó en varios pasos. Primero, durante un experimento indoor, se analizaron las respuestas bioquímicas en invertebrados sometidos a estrés acústico, Arbacia lixula y Mytilus galloprovincialis. Los resultados demostraron efectos significativos en la actividad de citotoxicidad, expresión de heat shock protein (HSPs) y actividades enzimáticas (esterasas, fosfatasas alcalinas, peroxidasas) en el líquido celomático de los erizos de mar sometidos a estrés acústico. También se observaron efectos significativos en el nivel de glucosa, la citotoxicidad y las actividades enzimáticas (esterasa, fosfatasa alcalina, peroxidasa) de la glándula digestiva del mejillón. En segundo lugar, se analizaron las respuestas bioquímicas de vertebrados e invertebrados sometidos in-situ a la emisión de watergun: Chromis chromis, Holothuria tubulosa y Arbacia lixula. Se encontraron efectos significativos sobre los niveles de cortisol en peces y las actividades enzimáticas (esterasas, fosfatasas alcalinas, peroxidasas y superoxide dismutasas) en membrana peristomial de erizo de mar. Además, las respuestas bioquímicas enzimáticas analizadas en los fluidos celómicos de los equinodermos fue significativa solo por A. lixula y solo en la activade peroxidasica. Tercero se estudiaron los cambios de comportamiento en las condiciones experimentales en juveniles de Sparus aurata sometidos a 4 frecuencias de emisión acústica diferentes. Este experimento demostró que solo las bajas frecuencias tuvieron efectos en todas las respuestas comportamental: altura de natación, motilidad y dispersión del grupo. Sobre la base de los datos de comportamiento obtenidos in vivo en peces jóvenes, se creó un modelo numérico para predecir los impactos de diferentes frecuencias de emisión acústica. Utilizando los resultados obtenidos y la bibliografía científica, se propuso un primer estándar técnico que es útil para la minería. / [CA] A lo llarc de l'historia, l'home ha explotat els recursos minerals de la terra per a la seua supervivencia i desenroll tecnologic sense un equilibri en la seua regeneracio. Donat el creiximent de la poblacio mundial i la reduccio de recursos, l'home escomençà a buscar nous deposits que se trobaren en la decada de 1960 en les fondaries dels oceans. En estos, l'humanitat empezò a pensar en extraure els minerals d'estos deposits i aço llevò al naiximent de Deep Sea Mining (DSM). Les conseqüencies de les activitats mineres en les fondaries del mar no se coneixen realment i els efectes poden ser diferents: contaminacio acustica, contaminacio lluminica, contaminacio quimica, destruccio de l'habitat, fragmentacio de l'habitat i perdua d'especies que son la base de molts sistemes vitals. L'impacte acustic d'estes activitats pot tindre importants conseqüencies en les especies marines, encara que este es el tema mes ignorat. El proposit d'este proyecte de doctorat fon proporcionar una comprensio basica dels possibles impactes acustics del DSM en la biodiversidad abans de que escomencen estes activitats. Per a fer aço, el proyecte de doctorat s'organisà en varis passos. Primer, durant un experiment indoor, s'analisaren les respostes bioquimiques en invertebrats somesos a estrés acustic, Arbacia lixula i Mytilus galloprovincialis. Els resultats demostraren efectes significatius en l'activitat de citotoxicidad, expressio d'heat shock protein (HSPS) i activitats enzimáticas (esterasa, fosfatasas alcalina, peroxidasas) en el liquit celomático dels capellanets de mar somesos a estrés acustic. Tambe s'observaren efectes significatius en el nivell de glucosa, la citotoxicidad i les activitats enzimáticas (esterasa, fosfatasa alcalina, peroxidasas) de la glandula digestiva de la clochina. En segon lloc, s'analisaren les respostes bioquimiques de vertebrats i invertebrats somesos in-situ a l'emissio de watergun: Chromis chromis, Holothuria tubulosa i Arbacia lixula. se trobaren efectes significatius sobre els nivells de cortisol en peixos i les activitats enzimáticas (esterasas, fosfatasas alcalines, peroxidasas y superoxide dimutases) en peristomes de capellanet de mar. Ademes, les respostes bioquimiques enzimáticas analisades en els decorreguts celómicos dels equinoderms fon significativa nomes per A. lixula i nomes en l'activade peroxidasica. Tercer s'estudiaren els canvis de comportament en les condicions experimentals en jovenils de Sparus aurata somesos a 4 freqüencies d'emissio acustica diferents. Este experiment demostrà que nomes les baixes freqüencies tingueren efectes en totes les respostes comportamental: alçada de natacio, motilidad i escampada del grup. Sobre la base de les senyes de comportament obtinguts in vivo en peixos jovens, se creó un model numeric per a predecir els impactes de diferents freqüencies d'emissio acustica. Utilisant els resultats obtinguts i la bibliografia cientifica, se propongue un primer estandart tecnic que es util per a la mineria. / [EN] Throughout history, man has exploited the earth's mineral resources for its survival and for technological development without regard for their regeneration. Given the growth of the world population and given the fall in resources, man started looking for new deposits, which were found in 1960s in the ocean depths. Humankind then began to consider extracting minerals from these deposits and this gave origin to Deep Sea Mining (DSM). The consequences of mining activities in the deep sea are not entirely known and the effects can be varied: noise pollution, light pollution, chemical pollution, habitat destruction, habitat fragmentation and the loss of species which we consider the basis of many life systems. The acoustic impact of these activities could have significant consequences on marine species; nevertheless, this has been the most overlooked issue to date. The aim of this PhD project was to provide baseline knowledge of possible acoustic impacts of DSM on biodiversity before mining begins. In order to do this, the PhD project was organised into 3 different stages. First, during an indoor experiment, the biochemical responses of invertebrates Arbacia lixula and Mytilus galloprovincialis subjected to acoustic stress were analysed. The results showed significant changes in cytotoxicity activity, expression of heat shock proteins (HSPs), and enzyme activities (esterases, alkaline phosphatases, peroxidases) in the coelomic fluid of sea urchins subjected to acoustic stress. Significant effects were also observed in glucose levels, cytotoxicity and enzyme activities (esterase, alkaline phosphatase, peroxidase) in the digestive gland of the mussel. Second, the biochemical responses of vertebrates and invertebrates subjected in-situ to watergun emission were analysed: Chromis chromis, Holothuria tubulosa and Arbacia lixula. Significant effects on fish cortisol levels and on enzyme activities in sea urchin peristomes were found. Furthermore, the enzyme biochemical responses analysed in the coelomic fluids of echinoderms showed significant effects only in A. lixula sea urchin and only in peroxidase activity. Third, behavioural changes in experimental conditions were studied in juveniles of Sparus aurata subjected to 4 different acoustic emission frequencies. This experiment showed that only low frequencies had effects on all the behavioural responses analysed: swimming height, motility and dispersion of the group. Based on behavioural data obtained in vivo on juvenile fish, a numerical model was created to predict the impacts of different acoustic emission frequencies. Using the results obtained and literature, a first technical standard useful for mining activities was drawn up. / The study of the Section 3.3 was supported by grants from MIUR (Ministry of Education, University and Research), Fondo Finalizzato alla Ricerca di Ateneo (FFR, 2018-2021) to M.V. and by the CNR research project: IMPLEMENTATION OF THE SOS CONVENTION - Offshore Platforms & Impacts between MATTM and CNR-DTA, (Capo Granitola, Campobello di Mazara) Work Package E: Indepth technical and scientific evaluation of the effects on marine ecosystems of airgun technologies and the effects of a watergun The study of the Section 3.4 study was conducted in the framework of the PhD program in Mediterranean Biodiversity XXXII cycle (International) of the University of Palermo. I. Perez-Arjona, M. Bou-Cabo and V. Espinosa acknowledge the financial support of the European Comission -project 11.0661/2018794607/SUB/ENV.C2. Risk-based Approaches to Good Environmental Status (RAGES). The other founding supports come from PhD Innovative with Industrial Characterization PON 2014-2020 and the projects CAIMAR Joint Laboratory Italy-Argentina (Laboratori Congiunti Bilaterali Internazionali of the Italian National Reseach Council, 2017-2019) and BOSS – Study of bioacoustics and applications for the sustainable exploitation of marine resources (Projects of major importance in the Scientific and Technological Collaboration Executive Programmes, funded by the Italian Ministry of Foreign Affairs and International Cooperation). / Mauro, M. (2020). Mining extraction in the ocean depths: a baseline to understand and reduce acoustic impact on biodiversity [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/144131 / Compendio

The present study characterized the deep-sea gastropods community collected on whale bones and wood parcels artificially implanted in the deep Southwest Atlantic Ocean at 1500 and 3300 m depth for 23 months. A total of 5493 gastropods were collected and their distribution, abundance and diversity on substrates, depths and latitudes were calculated. Species richness and abundance of gastropods were higher in whale bones and deeper sites. Latitude did not seem to influence the distribution of mollusks. Five species were selected due to their abundance and possible ecological importance for further studies. Three were new species of the superfamily Abyssochrisoidea and were morphologically and genetically described (two Rubyspira and one Cordesia). The other two were Hyslogyrina rissoela (Heterobranchia) and Lusitanops cingulatus (Neogastropoda). To understand their feeding behavior and dispersal strategies were conduced stable isotopes analyzes, observations of gut content, and radular and larval shell morphology. Larval shell of most species suggested planktotrophic development. Animals on different growth stages were found. Gastropods presented a diversity of feeding strategies, such as bacterial mats grazing, predation and specialized bone eating. The overlap of this fauna with other chemosynthetic environments and with other basins corroborate with the ecological stepping stone hypothesis. Besides that, phylogenetic studies about Abyssochrysoidea were made. Their phylogenetic position within the Caenogastropoda are still uncertain but this group is considered closely related with Littorinidae. These snails are endemic from chemosynthetic environments, such as deep-sea hydrothermal vents, cold seeps and organic falls in the deep-sea. The genus Rubyspira is not settled at family level and no molecular studies were made for Cordesia. The present study also attempts to assign these groups phylogenetically. Concatenated COI, 16S, 18S and 28S and individual gene trees were constructed for maximum likelihood and Bayesian analysis. In all analyses the family Newtoniellidae were a sister group of Abyssochrysoidea. Morphological and genetic evidences suggest that Rubyspira and Cordesia are closer related to Abyssochrysos than to other provannid snails. The most accepted hypothesis is that Provannidae is paraphyletic. However, there are other ideas that indicates Rubyspira and Cordesia could be included in Abyssochrysidae or the Provannidae should be considered Abyssochrysidae. A morphologic revision of the superfamily should be made to better understand the relation within the group. Clades within the Abyssochrysoidea were always well supported and similar to those found in the literature. The position of Rubyspira and Cordesia within Abyssochrysoidea suggest whale bones and wood parcels did not play an evolutionary role as stepping stones for this group. / O presente estudo caracterizou a comunidade de gastrópodes de mar profundo coletados em carcaças de baleia e parcelas de madeira artificialmente implantadas no Sudoeste do Oceano Atlântico profundo a 1500 e 3300 m de profundidade por 23 meses. Um total de 5493 gastrópodes foram coletados e sua distribuição, abundância e biodiversidade nos substratos, profundidades e latitudes foram calculados. A riqueza e abundância dos gastrópodes foi maior nos ossos de baleia e em maiores profundidades. A latitude parece não ter influenciado na distribuição dos moluscos. Cinco espécies foram selecionadas devido à abundância e possível importância ecológica. Três são novas espécies da superfamília Abyssochrysoidea que foram descritas morfologicamente e filogeneticamente (duas Rubyspira e uma Cordesia). As outras duas foram Hyalogirina rissoela (Heterobranchia) e Lusitanops cingulatus (Neogastropoda). Para compreender os hábitos alimentares e de dispersão desses animais análises de isótopos estáveis, observações do conteúdo do trato digestório, da morfologia das rádulas e das conchas larvais foram realizadas. A concha larval da maioria das espécies sugere um desenvolvimento planctotrófico. Os moluscos encontrados apresentaram diversos tipos de hábitos alimentares como raspadores de carpete bacteriano, predadores e especialistas de ossos. A sobreposição dessa fauna com a de outros ambientes quimiossintéticos e de outras bacias oceânicas colabora com a hipótese ecológica das \"stepping stones\" no mar profundo. Além disso, estudos sobre a posição filogenética dos Abyssochrysoidea foi feita. Sua posição nos Caenogastropoda ainda é incerta, mas são considerados próximos aos Littorinidae. Esses animais são endêmicos de ambientes quimiossintéticos, como fontes hidrotermais de mar profundo, fontes frias e quedas orgânicas. O gênero Rubyspira não está atribuído à nenhuma Família e não foram realizados estudos moleculares para Cordesia. Esse estudo também tenta organizar esses grupos filogeneticamente. Árvores concatenadas e individuais dos genes COI, 16S, 18S e 28S foram construídas para máxima verossimilhança e análise bayesiana. Em todos resultados a família Newtoniellidae foi um grupo irmão dos Abyssochrysoidea. Evidências morfológicas e genéticas s para que sugerem que Rubyspira e Cordesia então mais próximos dos Abyssochrysos do que de outros provannides. A teoria mais aceita é de que os Provannidae são parafileticos. Porém há outras ideias de que Rubyspira e Cordesia poderiam ser inclusos em Abyssochrysidae, ou que os Provannidae fossem considerados Abyssochrysidae. Uma revisão dessa superfamilia deveria se feita para entender as relações desse grupo. Os clados de Abyssochrysoidea sempre foram bem suportados como na literatura. A posição de Rubyspira e Cordesia nos Abyssochrysoidea. aponta que os ossos de baleia e parcelas de madeira possam não terem servido como \"stepping stones\" evolutivas para esses gastrópodes.

The present study characterized the deep-sea gastropods community collected on whale bones and wood parcels artificially implanted in the deep Southwest Atlantic Ocean at 1500 and 3300 m depth for 23 months. A total of 5493 gastropods were collected and their distribution, abundance and diversity on substrates, depths and latitudes were calculated. Species richness and abundance of gastropods were higher in whale bones and deeper sites. Latitude did not seem to influence the distribution of mollusks. Five species were selected due to their abundance and possible ecological importance for further studies. Three were new species of the superfamily Abyssochrisoidea and were morphologically and genetically described (two Rubyspira and one Cordesia). The other two were Hyslogyrina rissoela (Heterobranchia) and Lusitanops cingulatus (Neogastropoda). To understand their feeding behavior and dispersal strategies were conduced stable isotopes analyzes, observations of gut content, and radular and larval shell morphology. Larval shell of most species suggested planktotrophic development. Animals on different growth stages were found. Gastropods presented a diversity of feeding strategies, such as bacterial mats grazing, predation and specialized bone eating. The overlap of this fauna with other chemosynthetic environments and with other basins corroborate with the ecological stepping stone hypothesis. Besides that, phylogenetic studies about Abyssochrysoidea were made. Their phylogenetic position within the Caenogastropoda are still uncertain but this group is considered closely related with Littorinidae. These snails are endemic from chemosynthetic environments, such as deep-sea hydrothermal vents, cold seeps and organic falls in the deep-sea. The genus Rubyspira is not settled at family level and no molecular studies were made for Cordesia. The present study also attempts to assign these groups phylogenetically. Concatenated COI, 16S, 18S and 28S and individual gene trees were constructed for maximum likelihood and Bayesian analysis. In all analyses the family Newtoniellidae were a sister group of Abyssochrysoidea. Morphological and genetic evidences suggest that Rubyspira and Cordesia are closer related to Abyssochrysos than to other provannid snails. The most accepted hypothesis is that Provannidae is paraphyletic. However, there are other ideas that indicates Rubyspira and Cordesia could be included in Abyssochrysidae or the Provannidae should be considered Abyssochrysidae. A morphologic revision of the superfamily should be made to better understand the relation within the group. Clades within the Abyssochrysoidea were always well supported and similar to those found in the literature. The position of Rubyspira and Cordesia within Abyssochrysoidea suggest whale bones and wood parcels did not play an evolutionary role as stepping stones for this group. / O presente estudo caracterizou a comunidade de gastrópodes de mar profundo coletados em carcaças de baleia e parcelas de madeira artificialmente implantadas no Sudoeste do Oceano Atlântico profundo a 1500 e 3300 m de profundidade por 23 meses. Um total de 5493 gastrópodes foram coletados e sua distribuição, abundância e biodiversidade nos substratos, profundidades e latitudes foram calculados. A riqueza e abundância dos gastrópodes foi maior nos ossos de baleia e em maiores profundidades. A latitude parece não ter influenciado na distribuição dos moluscos. Cinco espécies foram selecionadas devido à abundância e possível importância ecológica. Três são novas espécies da superfamília Abyssochrysoidea que foram descritas morfologicamente e filogeneticamente (duas Rubyspira e uma Cordesia). As outras duas foram Hyalogirina rissoela (Heterobranchia) e Lusitanops cingulatus (Neogastropoda). Para compreender os hábitos alimentares e de dispersão desses animais análises de isótopos estáveis, observações do conteúdo do trato digestório, da morfologia das rádulas e das conchas larvais foram realizadas. A concha larval da maioria das espécies sugere um desenvolvimento planctotrófico. Os moluscos encontrados apresentaram diversos tipos de hábitos alimentares como raspadores de carpete bacteriano, predadores e especialistas de ossos. A sobreposição dessa fauna com a de outros ambientes quimiossintéticos e de outras bacias oceânicas colabora com a hipótese ecológica das \"stepping stones\" no mar profundo. Além disso, estudos sobre a posição filogenética dos Abyssochrysoidea foi feita. Sua posição nos Caenogastropoda ainda é incerta, mas são considerados próximos aos Littorinidae. Esses animais são endêmicos de ambientes quimiossintéticos, como fontes hidrotermais de mar profundo, fontes frias e quedas orgânicas. O gênero Rubyspira não está atribuído à nenhuma Família e não foram realizados estudos moleculares para Cordesia. Esse estudo também tenta organizar esses grupos filogeneticamente. Árvores concatenadas e individuais dos genes COI, 16S, 18S e 28S foram construídas para máxima verossimilhança e análise bayesiana. Em todos resultados a família Newtoniellidae foi um grupo irmão dos Abyssochrysoidea. Evidências morfológicas e genéticas s para que sugerem que Rubyspira e Cordesia então mais próximos dos Abyssochrysos do que de outros provannides. A teoria mais aceita é de que os Provannidae são parafileticos. Porém há outras ideias de que Rubyspira e Cordesia poderiam ser inclusos em Abyssochrysidae, ou que os Provannidae fossem considerados Abyssochrysidae. Uma revisão dessa superfamilia deveria se feita para entender as relações desse grupo. Os clados de Abyssochrysoidea sempre foram bem suportados como na literatura. A posição de Rubyspira e Cordesia nos Abyssochrysoidea. aponta que os ossos de baleia e parcelas de madeira possam não terem servido como \"stepping stones\" evolutivas para esses gastrópodes.

Deep-sea bamboo coral (Isidella sp.) SE000901A from the southern Oregon coast (water depth 1048m) provides a high-resolution record of variability of North Pacific Intermediate Water (NPIW) and carbon rain to the sea floor, related to coastal upwelling, from 1808 to 2000AD. Counting of annual layers in magnesium to calcium (Mg/Ca) variations, measured by electron microprobe analysis, yields a detailed age model that is transferred directly to records of carbon and oxygen isotope ratios (δ¹³C and δ¹⁸O) measured by isotope ratio mass spectrometry and trace element ratios measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). A significant linear relationship between δ¹³C and δ¹⁸O measured on the carbonate internode of the coral specimen revealed disequilibrium kinetic isotopic variations that depend on calcification rate. The stable isotopic time series are significantly correlated to cadmium to calcium ratios (Cd/Ca) in the carbonate internode, suggesting that cadmium uptake also reflects the rate of calcification. Comparison of phosphorus to calcium ratios (P/Ca) in the carbonate internode to historical records of oxygen concentrations of NPIW suggests that coralline P/Ca is related to the phosphate content of the ambient bottom water, which covaries inversely with oxygen concentration. Stable carbon and nitrogen isotopic ratios (δ¹³C and δ¹⁵N) were measured on two organic gorgonin nodes of our bamboo coral, but incomplete understanding of the gorgonin growth patterns and the difficulty in translating ages between the proteinaceous node and calcareous internode preclude detailed comparison between organic stable isotopes and the trace element and isotopic composition of the well-dated carbonate proxies. Based on correlation of the measured properties to historical variations in coastal upwelling, and high-latitude climate variability, we demonstrate the potential and challenges in using deep-sea bamboo corals to extend records of climate variability into the pre-historical past. / Graduation date: 2012