hydrothermal vents
Recently Published Documents


TOTAL DOCUMENTS

1230
(FIVE YEARS 283)

H-INDEX

72
(FIVE YEARS 8)

Author(s):  
Futa Nakasugi ◽  
Motohiro Shimanaga ◽  
Hidetaka Nomaki ◽  
Hiromi Kayama Watanabe ◽  
Tomo Kitahashi ◽  
...  

Abstract Dirivultid copepods (Siphonostomatoida), one of the most successful meiobenthic organisms found at deep-sea hydrothermal vents, have been the focus of most previous ecological studies among meiofauna in these habitats. The ecology of Harpacticoida, a major benthic copepod group in typical deep-sea floor, however, is not well understood in terms of variations in community structure and controlling factors at venting sites. The spatial heterogeneities in benthic harpacticoid composition and their association with environmental parameters were investigated at hydrothermal vent chimney structures in the calderas of three neighbouring sea knolls (Bayonnaise Knoll, Myojin Knoll and Myojin-sho Caldera) in the western North Pacific. While a previous study had reported the distribution of dirivultids was strongly associated with spatial differences in stable carbon isotopic signatures (δ13C) of organic matter in the detritus on active chimneys in the field, multivariate analyses detected no significant corelation between the parameter and harpacticoid composition in this study. Instead, high associations of the harpacticoid composition with differences in water depth and total organic carbon (TOC) concentration were detected. Ectinosomatidae dominated at vent sites with lower TOC values in the shallowest Bayonnaise Knoll, while they were less prevalent at deeper vent fields in the other knolls, where Miraciidae was the most abundant family. This study indicated the availability of vent chemoautotrophic carbon is not a primary factor controlling the composition of harpacticoids even in the habitats on the hydrothermal vents, but instead by the food amount, regardless of its resources (including marine snow from the sea surface), in the study area.


2022 ◽  
Vol 8 ◽  
Author(s):  
Charlotte Kleint ◽  
Rebecca Zitoun ◽  
René Neuholz ◽  
Maren Walter ◽  
Bernhard Schnetger ◽  
...  

Hydrothermal vents are a source of many trace metals to the oceans. Compared to mid-ocean ridges, hydrothermal vent systems at arcs occur in shallower water depth and are much more diverse in fluid composition, resulting in highly variable water column trace metal concentrations. However, only few studies have focused on trace metal dynamics in hydrothermal plumes at volcanic arcs. During R/V Sonne cruise SO253 in 2016/2017, hydrothermal plumes from two hydrothermally active submarine volcanoes along the Kermadec arc in the Southwest Pacific Ocean were sampled: (1) Macauley, a magmatic dominated vent site located in water depths between 300 and 680 m, and (2) Brothers, located between 1,200 and 1,600 m water depth, where hydrothermalism influenced by water rock interactions and magmatically influenced vent sites occur near each other. Surface currents estimated from satellite-altimeter derived currents and direct measurements at the sites using lowered acoustic Doppler current profilers indicate the oceanic regime is dominated by mesoscale eddies. At both volcanoes, results indicated strong plumes of dissolved trace metals, notably Mn, Fe, Co, Ni, Cu, Zn, Cd, La, and Pb, some of which are essential micronutrients. Dissolved metal concentrations commonly decreased with distance from the vents, as to be expected, however, certain element/Fe ratios increased, suggesting a higher solubility of these elements and/or their stronger stabilization (e.g., for Zn compared to Fe). Our data indicate that at the magmatically influenced Macauley and Brothers cone sites, the transport of trace metals is strongly controlled by sulfide nanoparticles, while at the Brothers NW caldera wall site iron oxyhydroxides seem to dominate the trace metal transport over sulfides. Solution stabilization of trace metals by organic complexation appears to compete with particle adsorption processes. As well as extending the generally sparse data set for hydrothermal plumes at volcanic arc systems, our study presents the first data on several dissolved trace metals in the Macauley system, and extends the existing plume dataset of Brothers volcano. Our data further indicate that chemical signatures and processes at arc volcanoes are highly diverse, even on small scales.


2022 ◽  
Author(s):  
Kai Zhang ◽  
Yao Xiao ◽  
Jin Sun ◽  
Ting Xu ◽  
Kun Zhou ◽  
...  

Abstract Background Symbiosis with chemosynthetic bacteria has allowed many invertebrates to flourish in ‘extreme’ deep-sea chemosynthesis-based ecosystems, such as hydrothermal vents and cold seeps. Bathymodioline mussels are considered as models of deep-sea animal-bacteria symbiosis, but the diversity of molecular mechanisms governing host-symbiont interactions remains understudied owing to the lack of hologenomes. In this study, we adopted a total hologenome approach in sequencing the hydrothermal vent mussel Bathymodiolus marisindicus and the endosymbiont genomes combined with a transcriptomic and proteomic approach that explore the mechanisms of symbiosis. Results Here, we provide the first coupled mussel-endosymbiont genome assembly. Comparative genome analysis revealed that both Bathymodiolus marisindicus and its endosymbiont reshape their genomes through the expansion of gene families, likely due to chemosymbiotic adaptation. Functional differentiation of host immune-related genes and attributes of symbiont self-protection that likely facilitate the establishment of endosymbiosis. Hologenomic analyses offer new evidence that metabolic complementarity between the host and endosymbionts enables the host to compensate for its inability to synthesize some essential nutrients, and two pathways (digestion of symbionts and molecular leakage of symbionts) that can supply the host with symbiontderived nutrients. Results also showed that bacteriocin and abundant toxins of symbiont may contribute to the defense of the B. marisindicus holobiont. Moreover, an exceptionally large number of anti-virus systems were identified in the B. marisindicus symbiont, which likely work synergistically to efficiently protect their hosts from phage infection, indicating virus-bacteria interactions in intracellular environments of a deepsea vent mussel. Conclusions Our study provides novel insights into the mechanisms of symbiosis enabling deep-sea mussels to successfully colonize the special hydrothermal vent habitats.


2022 ◽  
Vol 8 ◽  
Author(s):  
Katharina Kniesz ◽  
Anna Maria Jażdżewska ◽  
Pedro Martínez Arbizu ◽  
Terue Cristina Kihara

Hydrothermal vent areas have drawn increasing interest since they were discovered in 1977. Because of chemoautotrophic bacteria, they possess high abundances of vent endemic species as well as many non-vent species around the fields. During the survey conducted by the Bundesanstalt für Geowissenschaften und Rohstoffe (Federal Institute for Geosciences and Natural Resources, BGR) to identify inactive polymetallic sulfide deposits along Central and Southeast Indian Ridges, the INDEX project studied the scavenging amphipod community at three newly discovered hydrothermal fields. A sample consisting of 463 representatives of Amphipoda (Malacostraca: Crustacea) was collected by means of baited traps in active and inactive vents of three different sites and subsequently studied by both morphological and genetic methods. Molecular methods included the analysis of two mitochondrial (cytochrome c oxidase subunit I [COI] and 16S rRNA) and one nuclear (18S rRNA) genes. By six delimitation methods, 22 molecular operational taxonomic units (MOTUs) belonging to 12 genera and 10 families were defined. The existence of potential species complexes was noted for the representatives of the genus Paralicella. The inactive site, where 19 species were found, showed higher species richness than did the active one, where only 10 taxa were recorded. Seven genera, Ambasiopsis, Cleonardo, Eurythenes, Parandania, Pseudonesimus, Tectovalopsis, and Valettiopsis, were observed only at inactive sites, whereas Haptocallisoma, was collected exclusively at active ones. The species Abyssorchomene distinctus (Birstein and Vinogradov, 1960), Hirondellea brevicaudata Chevreux, 1910, and Hirondellea guyoti Barnard and Ingram, 1990, have been previously reported from vent sites in the Atlantic or Pacific oceans. The present study provides the first report of Eurythenes magellanicus (H. Milne Edwards, 1848) and five other already described species in the Indian Ocean. The addition of 356 sequences strongly increases the number of amphipod barcodes in reference databases and provides for the first time COI barcodes for Cleonardo neuvillei Chevreux, 1908, Haptocallisoma abyssi (Oldevig, 1959), Hirondellea guyoti, Tectovalopsis fusilus Barnard and Ingram, 1990, and the genera Haptocallisoma, Pseudonesimus, and Valettiopsis.


2022 ◽  
Author(s):  
Muhammed Fatih Sert ◽  
Helge Niemann ◽  
Eoghan P. Reeves ◽  
Mats A. Granskog ◽  
Kevin P. Hand ◽  
...  

Abstract. Hydrothermal vents modify and displace subsurface dissolved organic matter (DOM) into the ocean. Once in the ocean, this DOM is transported together with elements, particles, dissolved gases, and biomass along with the neutrally buoyant plume layer. Considering the number and extent of actively venting hydrothermal sites in the oceans, their contribution to the oceanic DOM pool may be substantial. Here, we investigate the dynamics of DOM in relation to hydrothermal venting and related processes at the as-yet unexplored Aurora hydrothermal vent field within the ultraslow spreading Gakkel Ridge in the Arctic Ocean at 82.9° N. We examined the vertical distribution of DOM composition from sea ice to deep waters at six hydrocast stations distal to the active vent and its neutrally buoyant plume layer. In comparison to background seawater, we found that the DOM in waters directly affected by the hydrothermal plume was composed of lower numbers of molecular formulas and 5–10 % less abundant compositions associated with the molecular categories related to lipid and protein-like compounds. Samples that were not directly affected by the plume, on the other hand, were chemically more diverse and had a higher percentage of chemical formulas associated with the carbohydrate-like category. We suggest, therefore, that hydrothermal processes at Aurora may influence the DOM distribution in the bathypelagic ocean by spreading more thermally and/or chemically induced compositions, while DOM compositions in epipelagic and mesopelagic layers are mainly governed by the microbial carbon pump dynamics, and sea ice surface water interactions.


2022 ◽  
pp. 104084
Author(s):  
Lauren E. Kipp ◽  
Matthew A. Charette ◽  
Douglas E. Hammond ◽  
Willard S. Moore

2022 ◽  
pp. 334-361
Author(s):  
Rakesh Goswami ◽  
Bidyut Bandyopadhyay ◽  
Sanjoy Sadhukhan

Bacterial exopolysaccharides have enormous diversity with valuable characteristics, synthesized by various pathways in extreme conditions like salinity, geothermal springs, or hydrothermal vents. Due to extreme environments, these microorganisms have various adaption principles (e.g., low pH, high temperature, high saltation, and high radiation). Exopolysaccharide is an organic compound produced by most bacteria during fermentation using various carbon sources, resulting in a jelly-like or mass network structure outside the cell wall. This biopolymer has an adherent cohesive layer throughout the cell layer. Hot spring bacterial polysaccharides contain diverse extracellular polymeric substances. With a gain in popularity in applications of thermophilic microbial polysaccharides and its demand in diverse value-added industrial products, this chapter aims to provide valuable information on the physicochemical function and biotechnological applications in the field of food, medical imaging, nano-drugs, bioremediation, cancer, anti-bacterial, tissue engineering, etc.


2021 ◽  
pp. 82-96
Author(s):  
Franklin M. Harold

The origin of life is the most consequential problem in biology, possibly in all of science, and it remains unsolved. This chapter summarizes what has been learned and highlights questions that remain open, including How, Where, When, and especially Why. LUCA, some four billion years ago, already featured the basic capacities of contemporary cells. These must have evolved still earlier, at a nebulous proto-cellular stage. There is good reason to believe that enzymes, DNA, ribosomes, electron-transport chains, and the rotary ATP synthase all predate LUCA and were shaped by the standard process of variation and natural selection, but we know next to nothing about how cells ever got started. I favor the proposal that it began with a purely chemical dynamic network capable of reproducing itself, that may have originated by chance. Natural selection would have favored the incorporation of any ancillary factors that promoted its kinetic stability, especially ones that improved reproduction or gave access to energy. All the specifics are in dispute, including the role of a prebiotic broth of organic chemicals, the nature and origin of enclosure, the RNA world, and a venue in submarine hydrothermal vents. My sense is that critical pieces of the puzzle remain to be discovered.


Sign in / Sign up

Export Citation Format

Share Document