scholarly journals Polyp loss and mass occurrence of sea urchins on bamboo corals in the deep sea: an indirect effect of fishing impact?

Ecology ◽  
2021 ◽  
Author(s):  
Pål Buhl‐Mortensen ◽  
Andreia Braga‐Henriques ◽  
Angela Stevenson
Keyword(s):  
Indirect Effect ◽  
Deep Sea ◽  
Sea Urchins ◽  
Fishing Impact ◽  
Mass Occurrence

scholarly journals Methanotrophic bacterial symbionts fuel dense populations of deep-sea feather duster worms (Sabellida, Annelida) and extend the spatial influence of methane seepage

2020 ◽  
Vol 6 (14) ◽  
pp. eaay8562 ◽  
Author(s):  
Shana K. Goffredi ◽  
Ekin Tilic ◽  
Sean W. Mullin ◽  
Katherine S. Dawson ◽  
Abigail Keller ◽  
...  
Keyword(s):  
Deep Sea ◽  
Isotope Labeling ◽  
Cold Seeps ◽  
Methanotrophic Bacteria ◽  
Bacterial Symbionts ◽  
Methane Seepage ◽  
Spatial Influence ◽  
Methane Oxidizing Bacteria ◽  
Epidermal Surface ◽  
Mass Occurrence

Deep-sea cold seeps are dynamic sources of methane release and unique habitats supporting ocean biodiversity and productivity. Here, we describe newly discovered animal-bacterial symbioses fueled by methane, between two species of annelid (a serpulid Laminatubus and sabellid Bispira) and distinct aerobic methane-oxidizing bacteria belonging to the Methylococcales, localized to the host respiratory crown. Worm tissue δ13C of −44 to −58‰ are consistent with methane-fueled nutrition for both species, and shipboard stable isotope labeling experiments revealed active assimilation of 13C-labeled methane into animal biomass, which occurs via the engulfment of methanotrophic bacteria across the crown epidermal surface. These worms represent a new addition to the few animals known to intimately associate with methane-oxidizing bacteria and may further explain their enigmatic mass occurrence at 150–million year–old fossil seeps. High-resolution seafloor surveys document significant coverage by these symbioses, beyond typical obligate seep fauna. These findings uncover novel consumers of methane in the deep sea and, by expanding the known spatial extent of methane seeps, may have important implications for deep-sea conservation.

scholarly journals Environmental and Geomorphological Effects on the Distribution of Deep-Sea Canyon and Seamount Communities in the Northwest Atlantic

2021 ◽  
Vol 8 ◽  
Author(s):  
Kristen Mello-Rafter ◽  
Derek Sowers ◽  
Mashkoor Malik ◽  
Les Watling ◽  
Larry A. Mayer ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Composition ◽  
New England ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Sea Urchins ◽  
Environmental Parameters ◽  
Anthropogenic Pressures ◽  
Northwest Atlantic ◽  
Significant Difference

Deep sea canyons and seamounts are topographically complex features that are considered to be biological hotspots. Anthropogenic pressures related to climate change and human activities are placing the species that inhabit these features at risk. Though studies have examined species composition on seamounts and canyons, few have compared communities between them, and even fewer studies have examined how species’ abundances correlate with environmental conditions or geomorphology. Consequently, this study compares species composition, community structure, and environmental variables between Northwest Atlantic continental margin canyons and seamounts along the New England Seamount Chain. Geoforms were also related to the occurrence of phyla and biodiversity. Overall, there was a significant difference in species composition between canyons and seamounts with sponges, corals, sea urchins and seastars contributing heavily to observed differences. Environmental conditions of temperature and salinity and the seafloor property slope contributed significantly to communities observed on seamounts, while substrate, depth and salinity contributed significantly to canyon communities. Abundances were significantly higher in canyons, but taxonomic richness, evenness, and diversity were all greater on seamounts. In an era where climate change and human activity have the potential to alter environmental parameters in the deep sea, it is important to examine factors that influence the spatial distribution of deep-sea benthic communities.

scholarly journals Sequestration of Methane by Symbiotic Deep-Sea Annelids: Ancient and Future Implications of Redefining the Seep Influence

2019 ◽  
Author(s):  
Shana K. Goffredi ◽  
Ekin Tilic ◽  
Sean W. Mullin ◽  
Katherine S. Dawson ◽  
Abigail Keller ◽  
...  
Keyword(s):  
High Resolution ◽  
Greenhouse Gas ◽  
Deep Sea ◽  
Gas Production ◽  
Methanotrophic Bacteria ◽  
Undescribed Species ◽  
Methane Seeps ◽  
Methane Oxidizing Bacteria ◽  
Epidermal Surface ◽  
Mass Occurrence

AbstractDeep-sea methane seeps are dynamic sources of greenhouse gas production and unique habitats supporting ocean biodiversity and productivity. Here, we demonstrate new animal-bacterial symbioses fueled by methane, between two undescribed species of annelid (a serpulid Laminatubus and sabellid Bispira) and distinct methane-oxidizing Methylococcales bacteria. Worm tissue δ13C of −44‰ to −58‰ suggested methane-fueled nutrition for both species and shipboard experiments revealed active assimilation of 13C-labelled CH4 into animal biomass, occurring via engulfment of methanotrophic bacteria across the host epidermal surface. These worms represent a new addition to the few animals known to intimately associate with methane-oxidizing bacteria, and further explain their enigmatic mass occurrence at 150-million-year-old fossil seeps. High-resolution seafloor surveys document significant coverage by these symbioses, beyond typical obligate seep fauna. These findings uncover novel consumers of methane in the deep-sea, and by expanding the known spatial extent of methane seeps, may have important implications for deep-sea conservation.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Fate of sperm membrane in fertilized ova

1993 ◽  
Vol 51 ◽  
pp. 40-41
Author(s):  
Frank J. Longo
Keyword(s):  
Electron Microscopy ◽  
Electrical Activity ◽  
Sea Urchins ◽  
Morphological Changes ◽  
Integrated System ◽  
Electrophysiological Recording ◽  
Experimental Conditions ◽  
The Status ◽  
Sperm Membrane ◽  
Temporal And Spatial

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.

Sign in / Sign up

Export Citation Format

Share Document