Paralvinella Palmiformis Research Articles

Third-generation sequencing reveals the adaptive role of the epigenome in three deep-sea polychaetes.

The roles of DNA methylation in invertebrates are poorly characterised, and critical data are missing for the phylum Annelida. We fill this knowledge gap by conducting the first genome-wide survey of DNA methylation in the deep-sea polychaetes dominant in deep-sea vents and seeps: Paraescarpia echinospica, Ridgeia piscesae and Paralvinella palmiformis. DNA methylation calls were inferred from Oxford Nanopore sequencing after assembling high-quality genomes of these animals. The genomes of these worms encode all the key enzymes of the DNA methylation metabolism and possess a mosaic methylome similar to that of other invertebrates. Transcriptomic data of these polychaetes support the hypotheses that gene body methylation strengthens the expression of housekeeping genes and that promoter methylation acts as a silencing mechanism but not the hypothesis that DNA methylation suppress the activity of transposable elements. The conserved epigenetic profiles of genes responsible for maintaining homeostasis under extreme hydrostatic pressure suggest DNA methylation plays an important adaptive role in these worms.

Arsenic concentrations and species in three hydrothermal vent worms, Ridgeia piscesae, Paralvinella sulficola and Paralvinella palmiformis

Hydrothermal vents are surficial expressions of subsurface geological and hydrological processes. Fluids emitting from active vents are chemically distinct from bottom seawater, and are enriched in dissolved metals and metalloids, including arsenic. Vent organisms accumulate arsenic but the arsenic speciation in these non-photosynthetic organisms is largely unknown. Here, arsenic concentrations and chemical species were measured in three deep sea hydrothermal vent worms (Ridgeia piscesae, Paralvinella sulfincola and Paralvinella palmiformis ) from the Juan de Fuca Ridge in the Northwest pacific. R. piscesae has similar arsenic concentrations (3.8–35µgg−1) to shallow water polychaetes while P. sulfincola and P. palmiformis have significantly higher arsenic concentrations (420–1417 and 125–321µgg−1 respectively). R. piscesae contains appreciable quantities of inorganic arsenic (36±14%), monomethyl arsenic (2±2%), dimethyl arsenic (34±21%), an unknown methyl arsenical (7±16%), OSO3-arsenosugar (5±9%), TETRA (4±5%), ThioPO4/ThioDMAE (1±2%) and an unknown thio-arsenical (12±14%). These results suggests that host and symbionts are either involved in the methylation of arsenic, or are bathed in fluids enriched in methylated arsenic as a result of free-living microbial activity. The host carrying out methylation, however, cannot be ruled out. In contrast, 96–97% of the arsenic in P. sulfincola and P. palmiformis is inorganic arsenic, likely the result of arsenic precipitation within and upon the mucus they ingest while feeding. While all worms have oxo- and thio arsenosugars (2–30%), Paralvinella also have small amounts of arsenobetaine (<0.001–0.21%). The presence of arsenosugars, arsenobetaine and other minor arsenic species in the absence of photosynthesising algae/bacteria indicates that they may be formed by vent animals in the absence of sunlight, but at this time their formation cannot be explained.

Temporal and spatial variation in temperature experienced by macrofauna at Main Endeavour hydrothermal vent field

A significant focus of hydrothermal vent ecological studies has been to understand how species cope with various stressors through physiological tolerance and biochemical resistance. Yet, the environmental conditions experienced by vent species have not been well characterized. This objective requires continuous observations over time intervals that can capture environmental variability at scales that are relevant to animals. We used autonomous temperature logger arrays (four roughly parallel linear arrays of 12 loggers spaced every 10–12cm) to study spatial and temporal variations in the thermal regime experienced by hydrothermal vent macrofauna at a diffuse flow vent. Hourly temperatures were recorded over eight months from 2010 to 2011 at Grotto vent in the Main Endeavour vent field on the Juan de Fuca Ridge, a focus area of the Ocean Networks Canada cabled observatory. The conspicuous animal assemblages in video footage contained Ridgeia piscesae tubeworms, gastropods (primarily Lepetodrilus fucensis), and polychaetes (polynoid scaleworms and the palm worm Paralvinella palmiformis). Two dimensional spatial gradients in temperature were generally stable over the deployment period. The average temperature recorded by all arrays, and in some individual loggers, revealed distinctive fluctuations in temperature that often corresponded with the tidal cycle. We postulate that this may be related to changes in bottom currents or fluctuations in vent discharge. A marked transient temperature increase lasting over a period of days was observed in April 2011. While the distributions and behavior of Juan de Fuca Ridge vent invertebrates may be partially constrained by environmental temperature and temperature tolerance, except for the one transient high-temperature event, observed fluid temperatures were generally similar to the thermal preferences for some species, and typically well below lethal temperatures for all species. Average temperatures of the four arrays ranged from 4.1 to 11.0°C during the deployment, indicating that on an hourly timescale the temperature conditions in this tubeworm community were fairly moderate and stable. The generality of these findings and behavioral responses of vent organisms to predictable rhythmicity and non-periodic temperature shifts are areas for further investigation.

Heavy metals in the benthic animals from hydrothermal vents: Results of neutron activation analysis

A series of samples of inhabitants of hydrothermal vents were collected during the 12th cruise of R/V Akademik Mstislav Keldysh in Guaymas Basin (the Gulf of California) and the Axial Seamount area (Juan de Fuca Ridge). The concentrations of trace and heavy metals in the tissues of Ridgeia piscesae, Riftia pachyptila, and Paralvinella palmiformis were analyzed. The neutron-activation analysis revealed significantly higher concentrations of uranium in the tissues of Paralvinella palmiformis as compared to the ambient seawater. The possible reasons for such phenomenon are discussed. The data obtained by the neutron-activation method are compared with those obtained by the atomic-absorption method for the same tissues analyzed.

Pathways, activities and thermal stability of anaerobic and aerobic enzymes in thermophilic vent paralvinellid worms

Animals living at deep sea hydrothermal vents experience high values of both temper- ature and hypoxia/sulfide. In these harsh environments polychaetes represent an important propor- tion of the biomass and diversity. To determine the mechanisms facilitating survival, we investigated the activities and thermal stability of 6 enzymes functioning under anaerobic and aerobic conditions, as well as glycogen levels, in 2 paralvinellid species from hydrothermal vents. In addition, the enzyme activities of several polychaetes from hydrocarbon cold seeps, which encounter low oxygen and high sulfide, but not elevated temperature, were investigated for comparative purposes. 'Anaer- obic' (lactate dehydrogenase, opine dehydrogenases) and 'aerobic' enzyme (citrate synthase) activi- ties of hydrothermal vent paralvinellids were similar to those of shallow water polychaetes, and sig- nificantly higher than those in cold seep species. Surprisingly, we detected different metabolic pathways in various body parts of hot vent species. The branchiae were identified to be the body part in which aerobic metabolism likely dominates, whereas the body wall is the major focal point of anaerobic glycolysis. Enzyme activity levels remained nearly constant in paralvinellids maintained for up to 120 h in high-pressure chambers. Thermal stability observations of in vitro enzyme activi- ties showed stability after exposure to elevated temperatures: up to 60°C for lactate dehydrogenase and up to 50°C for opine dehydrogenases, the latter correlating with the preferred temperatures of living paralvinellids. Heat shock experiments with live specimens revealed lethal temperatures of 45°C for Paralvinella palmiformis and 63°C for P. sulfincola. Heat shock treatments also reduced enzyme activity. Glycogen levels in vent species were lower than in shallow water species, suggest- ing that paralvinellids can obtain carbon through feeding under anoxic conditions.

Spatial variation in the reproductive biology of Paralvinella palmiformis (Polychaeta: Alvinellidae) from a vent field on the Juan de Fuca Ridge

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 255:171-181 (2003) - doi:10.3354/meps255171 Spatial variation in the reproductive biology of Paralvinella palmiformis (Polychaeta: Alvinellidae) from a vent field on the Juan de Fuca Ridge Jonathan T. P. Copley1,*, Paul A. Tyler1, Cindy L. Van Dover2, Steven J. Philp1 1School of Ocean and Earth Science, Southampton Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH, United Kingdom 2Biology Department, College of William & Mary, Williamsburg, Virginia 23187, USA *Email: jtc@mail.soc.soton.ac.uk ABSTRACT: The microdistribution and dynamics of deep-sea hydrothermal vent communities often reflect the extreme heterogeneity of their environment. Here we present an assessment of spatial variation in the reproductive development of the alvinellid polychaete Paralvinella palmiformis at the High Rise vent field (Endeavour Segment, Juan de Fuca Ridge, NE Pacific). Samples collected from different locations across the vent field suggest patchy reproductive development for this species. Males and females from several locations contained few or no developing gametes, while gametes were abundant in samples collected at the same time from other locations. Samples lacking gametes were distinguished by body size-frequency distributions with peaks at smaller sizes and the presence or absence of other fauna consistent with early stage assemblages in a successional mosaic model previously proposed for Endeavour Segment communities. Where gametes were present, synchrony of reproductive development between females within samples and between samples was evident. Reproductive synchrony between pairs of samples initially declined over a 7 d interval between samples, suggesting a rapid rate of reproductive development for P. palmiformis. Samples collected 1 mo apart, however, displayed similar frequency distributions of developing gametes. A peak of mature male and female gametes appeared to develop and disappear within the limited temporal resolution of the samples, consistent with possible simultaneous maturation of gametes despite pseudocopulation and sperm storage in this species. KEY WORDS: Hydrothermal vents · Reproductive development · Spatio-temporal variation · Successional model Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 255. Online publication date: June 24, 2003 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2003 Inter-Research.

Food resource partitioning and competition among alvinellid polychaetes of Juan de Fuca Ridge hydrothermal vents

Biotic communities in highly variable, frequently perturbed habitats are usually ex- pected to be structured mainly by abiotic factors. In the highly variable deep-sea hydrothermal vent environment, physical and chemical factors are known to play an important role in limiting the dis- tribution and abundance of species, but the importance of biotic interactions remains largely unre- solved. The high density and biomass attained by the vent macrofauna suggest that resource parti- tioning and competition may be significant in these communities. This study of food resource utilisation at northeast Pacific deep-sea hydrothermal vents uses an approach based on stable carbon and nitrogen isotope analyses to characterise trophic interactions between the 3 dominant alvinellid polychaetes, Paralvinella palmiformis, P. sulfincola, and P. pandorae. We also examine size structure in sympatric and allopatric populations of P. palmiformis and P. pandorae. Results indicate that food resource partitioning occurs both intra- and interspecifically in P. palmiformis and P. sulfincola, and we advocate that this process contributes to explaining their co-existence at very high densities. In contrast, P. pandorae has a much more restricted trophic niche, overlaps P. palmiformis in diet and is much smaller in size when found in sympatry with P. palmiformis. P. pandorae is the most likely of the 3 species to be affected by intra- and/or interspecific competition for food, and this may explain the drastic change in the population size structure observed between successive years. Our work indi- cates that within the limits imposed by environmental conditions, biotic interactions such as food resource partitioning and competition can be significant factors structuring deep-sea hydrothermal vent communities.

Phylogenetic characterization of the bacterial assemblage associated with mucous secretions of the hydrothermal vent polychaete Paralvinella palmiformis

As part of an ongoing examination of microbial diversity associated with hydrothermal vent polychaetes of the family Alvinellidae, we undertook a culture-independent molecular analysis of the bacterial assemblage associated with mucous secretions of the Northeastern Pacific vent polychaete Paralvinella palmiformis. Using a molecular 16S rDNA-based phylogenetic approach, clone libraries were constructed from two samples collected from active sulfide edifices in two hydrothermal vent fields. In both cases, clone libraries were largely dominated by ϵ-Proteobacteria. Phylotypes belonging to the Cytophaga– Flavobacteria and to the Verrucomicrobia were also largely represented within the libraries. The remaining sequences were related to the taxonomic groups Fusobacteria, Green non-sulfur bacteria, Firmicutes, γ- and δ- Proteobacteria. To our knowledge, this is the first report of the presence of Verrucomicrobia, Fusobacteria and green non-sulfur bacteria on hydrothermal edifices. The potential functions of the detected bacteria are discussed in terms of productivity, recycling of organic matter and detoxification within the P. palmiformis microhabitat.

Phylogenetic characterization of the bacterial assemblage associated with mucous secretions of the hydrothermal vent polychaete Paralvinella palmiformis

As part of an ongoing examination of microbial diversity associated with hydrothermal vent polychaetes of the family Alvinellidae, we undertook a culture-independent molecular analysis of the bacterial assemblage associated with mucous secretions of the Northeastern Pacific vent polychaete Paralvinella palmiformis. Using a molecular 16S rDNA-based phylogenetic approach, clone libraries were constructed from two samples collected from active sulfide edifices in two hydrothermal vent fields. In both cases, clone libraries were largely dominated by epsilon-Proteobacteria. Phylotypes belonging to the Cytophaga-Flavobacteria and to the Verrucomicrobia were also largely represented within the libraries. The remaining sequences were related to the taxonomic groups Fusobacteria, Green non-sulfur bacteria, Firmicutes, gamma- and delta-Proteobacteria. To our knowledge, this is the first report of the presence of Verrucomicrobia, Fusobacteria and green non-sulfur bacteria on hydrothermal edifices. The potential functions of the detected bacteria are discussed in terms of productivity, recycling of organic matter and detoxification within the P. palmiformis microhabitat.

Polypeptide chain composition diversity of hexagonal‐bilayer haemoglobins within a single family of annelids, the Alvinellidae

Following previous analysis of the structure of Alvinella pompejana heaxagonal-bilayer haemoglobin (HBL Hb) [1], we report in this paper the structure of three other HBL Hbs belonging to Alvinella caudata, Paralvinella grasslei and Paralvinella palmiformis, members of the Alvinellidae, annelid family strictly endemic to deep-sea hydrothermal vents located on the ridge crests in the Pacific ocean. The multi-angle laser light scattering (MALLS) and fast protein liquid chromatography (FPLC) analysis revealed a broad range of molecular masses for the extracellular Hb molecules, 3517 +/- 14 kDa (A. caudata), 3822 +/- 28 kDa (P. grasslei) and 3750 +/- 150 kDa (P. palmiformis). Native and derivative Hbs (reduced, carbamidomethylated and deglycosylated) were analysed by electrospray ionization mass spectroscopy (ESI-MS) and the data was processed by the maximum entropy deconvolution system (MaxEnt). The most important difference between alvinellid HBL Hbs was the variation in their composition, from two to four monomeric globin chains, and from one to four linker chains. Therefore, despite the fact that all these species belong to a single family, notable differences in the polypeptide chain composition of their HBL Hbs were observed, probably accounting for their different functional properties as previously reported by this group Toulmond, A., El Idrissi Slitine, F., De Frescheville, J. & Jouin, C. (1990) Biol. Bull. 179, 366-373.

13C/12C of organisms from Juan de Fuca Ridge hydrothermal vents: a guide to carbon and food sources

Soft tissue δ13C values were determined in vestimentiferan tube worms, alvinellid polychaetes and molluscs from Axial Seamount and Middle Valley, North-east Pacific. Inorganic carbon in mollusc shells and water samples was also analysed. In the vestimentiferan,Ridgeia piscesae, which lives in symbiosis with sulphur-oxidizing chemolithoautotrophic bacteria, tissue samples from the Axial vents showed δ13C values from −11 to −16‰, whereas at Middle Valley, where venting occurs through sediments, the δ13C ranged from −16 to −26‰. The tissues of an associated polychaete,Paralvinella palmiformis, which feeds on free-living bacteria, had δ13C values in the range −21 to −26‰. The bivalveCalyptogenafrom Middle Valley was more depleted thanRidgeiaandParalvinella, −37‰, closer to the ratios found in chemolithoautotrophic symbioses in non-vent habitats. Considerable, but variable, depletion (−23 to −42‰) was found in small gastropods. Mollusc shells and diluted vent water differed little in δ13C compared to inorganic carbon in ambient deep sea-water.

Systematic and ecological characteristics of Paralvinella sulfincola Desbruyères and Laubier, a new polychaete (family Alvinellidae) from northeast Pacific hydrothermal vents

Polychaetes of the family Alvinellidae (Terrebellida) are endemic to hydrothermal vent communities. A new species from the Juan de Fuca and Gorda ridges in the Northeast Pacific is described; aspects of its buccal appendages, segment number, and uncini placement are unique. Because of initial confusion with a sympatric species, Paralvinella palmiformis Desbruyères and Laubier, protein mobilities were examined to differentiate the species electrophoretically with reference to a third alvinellid, Alvinella pompejana. Among the 17 loci scored, fewer than a quarter of the alleles were present in the two Paralvinella species; Paralvinella sulfincola n.sp. has several diagnostic allozymes. This new species inhabits tubes on the sides of active smoker chimneys and migrates upward as the chimney grows. Individuals are recorded within 1 cm of hydrothermal fluids at temperatures in excess of 300 °C; the species appears to have several molecular adaptations to high ambient temperatures. The Alvinellidae form a fascinating group within which to study phylogenetic and selective processes.

Phospholipid fatty acid composition of the deep-sea hydrothermal vent polychaete Paralvinella palmiformis (Polychaeta-ampharetidae): effects of thermal regime and comparison with two shallow-water confamilial species

1. 1. The fatty acid composition of the total phospholipid fraction was determined for specimens of Paralvinella palmiformis from hydrothermal vents on the Juan de Fuca Ridge. 2. 2. Animals collected from 17°C water had a significantly greater degree of fatty acid unsaturation than animals living at ca 30–40°C. 3. 3. Compared with two shallow-water, non-vent polychaetes from the same family ( Hobsonia florida and Amphicteis scaphobranchiata), Paralvinella has a greater proportion of 18:1, 18:2, and total polyunsaturated fatty acids and a smaller proportion of 20:1, 22:1 and total monounsaturated fatty acids.