scholarly journals Biodiversity of echinoids and their epibionts around the Scotia Arc, Antarctica

2008 ◽  
Vol 20 (3) ◽  
pp. 227-244 ◽  
Author(s):  
Katrin Linse ◽  
Lisa J. Walker ◽  
David K.A. Barnes
Keyword(s):  
Southern Ocean ◽  
Current Knowledge ◽  
Sea Urchins ◽  
Marine Biodiversity ◽  
Current View ◽  
Depth Range ◽  
Tissue Mass ◽  
Scotia Arc ◽  
Biodiversity Changes ◽  
Study Species

AbstractThe Scotia Arc, linking the Magellan region with the Antarctic Peninsula, comprises young and old islands both near continents and isolated, and is the only semi-continuous link between cool temperate and Antarctic environments. It is an ideal region for studies on how marine biodiversity changes across an extended transition zone. Echinoids (sea urchins) and their associated epibionts were found across depths from 91–1045 m, with 19 species from shelf and four from slope depths. The 23 species from 38 trawls represent 31% of all echinoid species known from the Southern Ocean and 38% of the shelf/upper slope echinoids. The specimens collected comprise representatives of the five families Cidaridae, Echinidae, Temnopleuridae, Schizasteridae and Pourtalesiidae. Echinoids are probably a good model for how well we know Antarctic shelf and slope megabenthos; none of the species we report are new to science but we found nine (39%) of our study species present at new localities, some thousands of kilometres from previous findings. New biogeographic ranges are illustrated forCtenocidaris gigantea,C. nutrix,C. spinosa,Abatus curvidens,A. ingens,A. shackletoni,Amphineustes rostratus,Tripylaster philippiandPourtalesia aurorae. Southern Ocean echinoids show eurybathy as the mean depth range of our study species was 1241 m and only one was at less than 500 m. The current view of echinoid dominance of super-abundance in the shallows seems to be not transferable to shelf and slope depths as only one of 38 trawls was dominated by echinoids. Current knowledge on maximum sizes in Antarctic echinoids seems to be good as our morphometric measurements were mainly within known size ranges. Regular echinoids increased predictably in mass with increasing test length, apart fromCtenocidaris spinosa. Tissue mass of cidaroid species was ~17%, but across irregular species varied from 17.7–8.9%. No epibionts were found on irregular echinoids or Echinidae but 70 cidaroids examined carried 51 species representing ten classes. Many of these species are reported as cidaroid epibionts for the first time. Cidaroids and their epibionts constituted > 38% of the total macrofaunal richness in the trawls they were present in. Echinoids and their epibionts clearly contribute significantly to Southern Ocean biodiversity but are minor components of biomass except in the shallows.

scholarly journals DENSIDAD POBLACIONAL DE CUATRO ESPECIES DE ERIZO (ECHINODERMATA: ECHINOIDEA) EN EL ARRECIFE DE LA ENTREGA, OAXACA

2005 ◽  
Vol 20 (1-2) ◽  
pp. 65
Author(s):  
P. Zamorano ◽  
G. E. Leyte-Morales
Keyword(s):  
Population Density ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Depth Range ◽  
Deep Zone ◽  
Total Abundance ◽  
Subsequent Increase ◽  
Shallow Zone ◽  
Over Time ◽  
Shallow Part

De octubre de 2002 a agosto de 2003 se realizaron muestreos bimestrales de la abundancia de erizos en el arrecife de La Entrega. El arrecife fue dividido en dos profundidades (somero 0-6 m y profundo 6-12 m). En cada profundidad se realizaron seis transectos de 50 m de largo por 1 m de ancho. La mayor densidad anual correspondió a Diadema mexicanum (5.96±0.85 ind/m2), seguido de Eucidaris thouarsii (0.46±0.14 ind/m2); Echinometra vanbrunti y Toxopneustes roseus presentaron densidades bajas (0.03±0.01 ind/m2 y 0.02±0.01 ind/m2, respectivamente). Las cuatro poblaciones de erizos presentaron diferencias entre profundidades observándose mayor densidad en lo profundo; si consideramos la abundancia total de erizos en el arrecife, no se registraron diferencias temporales. Empero, al analizar por separado las profundidades, sólo E. thouarsii no presentó diferencias temporales en ambas profundidades. En diciembre, las densidades de D. mexicanum y E. thouarsii disminuyeron en lo profundo y aumentaron en lo somero, posiblemente porque sucedió una mortalidad coralina en lo somero del arrecife y el incremento de las algas motivó a estas especies a desplazarse a la parte dañada. Actualmente el arrecife de La Entrega se encuentra en avanzado estado de erosión lo que puede favorecer que la abundancia de erizos se incremente al igual que su actividad bioerosionadora. Population density of four species of sea urchin (Echinodermata: Echinoidea) at La Entrega Reef, Oaxaca Bimonthly samples of sea urchins fauna inhabiting the La Entrega Reef, Oaxaca, Mexico, were obtained from October 2002 to August 2003. The reef area was divided in two sampling zones, corresponding to shallow (0-6 m) and deep (6-12 m) water. Six transects of 50 m length by 1 m wide were sampled in each zone. Greatest annual density corresponded to Diadema mexicanum (5.96 ± 0.85 ind/m2),followed by Eucidaris thouarsii (0.46 ± 0.14 ind/m2); Echinometra vanbrunti and Toxopneustes roseus presented low densities (0.03 ± 0.01 indv/m2 and 0.02 ± 0.01 ind/m2, respectively). Density of the four populations varied considerably and higher densities were observed in the deep zone. Total abundance of sea urchins (shallow and deep samples) did not vary significantly over time. Abundance per depth range, however, was different over time for all species except for E. thouarsii. In December densities of D. mexicanum and E. thouarsii decreased in the deep zone and increased in the shallow zone, due to massive mortality of coral in the shallow part of the reef and to subsequent increase of algal coverage attracting these species to the shallowest part of the reef. The La Entrega reef is presently in an advanced state of erosion that could favor an increase of sea urchins abundance and of their bioerosion activity.

scholarly journals Comparative marine biodiversity and depth zonation in the Southern Ocean: evidence from a new large polychaete dataset from Scotia and Amundsen seas

2017 ◽  
Vol 48 (1) ◽  
pp. 581-601 ◽  
Author(s):  
Lenka Neal ◽  
Katrin Linse ◽  
Madeleine J. Brasier ◽  
Emma Sherlock ◽  
Adrian G. Glover
Keyword(s):  
Southern Ocean ◽  
Marine Biodiversity ◽  
Depth Zonation

scholarly journals Biological and physical characterization of the seabed surrounding Ascension Island from 100–1000 m

2017 ◽  
Vol 97 (4) ◽  
pp. 647-659 ◽  
Author(s):  
E.T. Nolan ◽  
D.K.A. Barnes ◽  
J. Brown ◽  
K. Downes ◽  
P. Enderlein ◽  
...  
Keyword(s):  
Cold Water ◽  
Sea Urchins ◽  
Marine Ecosystems ◽  
Carbon Accumulation ◽  
Marine Biodiversity ◽  
Density Maximum ◽  
Camera System ◽  
Entire Area ◽  
Ascension Island ◽  
Underwater Camera

Recent studies have improved our understanding of nearshore marine ecosystems surrounding Ascension Island (central Atlantic Ocean), but little is known about Ascension's benthic environment beyond its shallow coastal waters. Here, we report the first detailed physical and biological examination of the seabed surrounding Ascension Island at 100–1000 m depth. Multibeam swath data were used to map fine scale bathymetry and derive seabed slope and rugosity indices for the entire area. Water temperature and salinity profiles were obtained from five Conductivity, Temperature, Depth (CTD) deployments, revealing a spatially consistent thermocline at 80 m depth. A camera lander (Shelf Underwater Camera System; SUCS) provided nearly 400 images from 21 sites (100 m transects) at depths of 110–1020 m, showing high variability in the structure of benthic habitats and biological communities. These surveys revealed a total of 95 faunal morphotypes (mean richness >14 per site), complemented by 213 voucher specimens constituting 60 morphotypes collected from seven targeted Agassiz trawl (AGT) deployments. While total faunal density (maximum >300 m−2 at 480 m depth) increased with rugosity, characteristic shifts in multivariate assemblage structure were driven by depth and substratum type. Shallow assemblages (~100 m) were dominated by black coral (Antipatharia sp.) on rocky substrata, cup corals (Caryophyllia sp.) and sea urchins (Cidaris sp.) were abundant on fine sediment at intermediate depths (250–500 m), and shrimps (Nematocarcinus spp.) were common at greater depths (>500 m). Other ubiquitous taxa included serpulid and sabellid polychaetes and brittle stars (Ophiocantha sp.). Cold-water corals (Lophelia cf. pertusa), indicative of Vulnerable Marine Ecosystems (VMEs) and representing substantial benthic carbon accumulation, occurred in particularly dense aggregations at <350 m but were encountered as deep as 1020 m. In addition to enhancing marine biodiversity records at this locality, this study provides critical baseline data to support the future management of Ascension's marine environment.

Intramuscular Haemangioma of the Extensor Pollicis Brevis Muscle with Periosteal Reaction of the Radius: A Case Report and Review of the Literature

2007 ◽  
Vol 35 (5) ◽  
pp. 724-730 ◽  
Author(s):  
EH Kayias ◽  
GI Drosos ◽  
KI Kazakos ◽  
C Iatrou ◽  
KS Blatsoukas ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Periosteal Reaction ◽  
Review Of The Literature ◽  
Tissue Mass ◽  
Bone Changes ◽  
History Of ◽  
Intramuscular Haemangioma ◽  
History Of Pain ◽  
The Right

We report the rare case of a histologically proven mixed-type intramuscular haemangioma, adjacent to the periosteum of the radius, that caused a periosteal reaction. We also carried out a review of the literature relevant to this case. A 28-year-old male professional drummer presented with an 8-month history of pain and swelling of the dorsal aspect of the right radius. Diagnosis was established on the basis of plain radiographs and magnetic resonance imaging, and was confirmed by histology. The lesion was treated solely by resection of the soft-tissue mass. The patient remained asymptomatic 4 years post-operatively, with no radiographic signs of recurrence. From a review of the literature, it is evident that the terminology for haemangiomas causing regional bone changes is unclear. A new classification of the intramuscular haemangiomas is proposed in order to distinguish between lesions that, according to current knowledge, exhibit radiological and clinical areas of overlap.

scholarly journals Listeria Pathogenesis and Molecular Virulence Determinants

2001 ◽  
Vol 14 (3) ◽  
pp. 584-640 ◽  
Author(s):  
José A. Vázquez-Boland ◽  
Michael Kuhn ◽  
Patrick Berche ◽  
Trinad Chakraborty ◽  
Gustavo Domı́nguez-Bernal ◽  
...  
Keyword(s):  
Life Cycle ◽  
Cell Biology ◽  
Current Knowledge ◽  
Molecular Genetic ◽  
Clinical Manifestations ◽  
Gravid Uterus ◽  
Infection Model ◽  
Current View ◽  
Immunocompromised Patients ◽  
Virulence Determinants

SUMMARY The gram-positive bacterium Listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. Pregnant women, neonates, the elderly, and debilitated or immunocompromised patients in general are predominantly affected, although the disease can also develop in normal individuals. Clinical manifestations of invasive listeriosis are usually severe and include abortion, sepsis, and meningoencephalitis. Listeriosis can also manifest as a febrile gastroenteritis syndrome. In addition to humans, L. monocytogenes affects many vertebrate species, including birds. Listeria ivanovii, a second pathogenic species of the genus, is specific for ruminants. Our current view of the pathophysiology of listeriosis derives largely from studies with the mouse infection model. Pathogenic listeriae enter the host primarily through the intestine. The liver is thought to be their first target organ after intestinal translocation. In the liver, listeriae actively multiply until the infection is controlled by a cell-mediated immune response. This initial, subclinical step of listeriosis is thought to be common due to the frequent presence of pathogenic L. monocytogenes in food. In normal indivuals, the continual exposure to listerial antigens probably contributes to the maintenance of anti-Listeria memory T cells. However, in debilitated and immunocompromised patients, the unrestricted proliferation of listeriae in the liver may result in prolonged low-level bacteremia, leading to invasion of the preferred secondary target organs (the brain and the gravid uterus) and to overt clinical disease. L. monocytogenes and L. ivanovii are facultative intracellular parasites able to survive in macrophages and to invade a variety of normally nonphagocytic cells, such as epithelial cells, hepatocytes, and endothelial cells. In all these cell types, pathogenic listeriae go through an intracellular life cycle involving early escape from the phagocytic vacuole, rapid intracytoplasmic multiplication, bacterially induced actin-based motility, and direct spread to neighboring cells, in which they reinitiate the cycle. In this way, listeriae disseminate in host tissues sheltered from the humoral arm of the immune system. Over the last 15 years, a number of virulence factors involved in key steps of this intracellular life cycle have been identified. This review describes in detail the molecular determinants of Listeria virulence and their mechanism of action and summarizes the current knowledge on the pathophysiology of listeriosis and the cell biology and host cell responses to Listeria infection. This article provides an updated perspective of the development of our understanding of Listeria pathogenesis from the first molecular genetic analyses of virulence mechanisms reported in 1985 until the start of the genomic era of Listeria research.

scholarly journals Assessing Fishing and Marine Biodiversity Changes Using Fishers' Perceptions: The Spanish Mediterranean and Gulf of Cadiz Case Study

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e85670 ◽  
Author(s):  
Marta Coll ◽  
Marta Carreras ◽  
Cristina Ciércoles ◽  
Maria-José Cornax ◽  
Giulia Gorelli ◽  
...  
Keyword(s):  
Marine Biodiversity ◽  
Gulf Of Cadiz ◽  
Gulf Of Cádiz ◽  
Biodiversity Changes

scholarly journals Morphogenesis: a focus on marine invertebrates

2019 ◽  
Vol 1 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Zhiyi Lv ◽  
Qiongxuan Lu ◽  
Bo Dong
Keyword(s):  
Marine Invertebrates ◽  
Current Knowledge ◽  
Sea Urchins ◽  
Imaging Techniques ◽  
Marine Animal ◽  
Sea Anemones ◽  
Marine Animals ◽  
Wide Range ◽  
Fast Development ◽  
Living Tissues

AbstractMorphogenesis is a process describing how the shapes of living tissues and bodies are created during development. Living and fossil organisms exhibit enormously diverse tissue architecture and body forms, although the functions of organs are evolutionally conserved. Current knowledge reveals that relatively conserved mechanisms are applied to control development among different species. However, the regulations of morphogenesis are quite diverse in detail. Animals in the ocean display a wide range of diversity of morphology suitable for their seawater environment. Nevertheless, compared with the intensive studies on terrestrial animals, research on marine animal morphogenesis is still insufficient. The increasing genomic data and the recently available gene editing methods, together with the fast development of imaging techniques, quantitative analyses and biophysical models, provide us the opportunities to have a deeper understanding of the principles that drive the diverse morphogenetic processes in marine animals. In this review, we summarize the recent studies of morphogenesis and evolution at molecular, cellular and tissue levels, with a focus on three model marine animals, namely ascidians, sea urchins and sea anemones.

scholarly journals Ecophysiology and ecological limits of symbiotrophic vesicomyid bivalves (Pliocardiinae) in the Southern Ocean

Polar Biology ◽  
2020 ◽  
Vol 43 (10) ◽  
pp. 1423-1437
Author(s):  
Katrin Linse ◽  
Julia D. Sigwart ◽  
Chong Chen ◽  
Elena M. Krylova
Keyword(s):  
Southern Ocean ◽  
Geothermal Energy ◽  
Ex Situ ◽  
Metabolic Rates ◽  
Remotely Operated Vehicle ◽  
Tissue Mass ◽  
Ice Shelves ◽  
Habitat Temperature ◽  
Antarctic Marine ◽  
Mode Of Life

Abstract Geothermal energy provides an important resource in Antarctic marine ecosystems, exemplified by the recent discovery of large-sized chemosymbiotic vesicomyid bivalves (subfamily Pliocardiinae) in the Southern Ocean. These clams, which we identified as Archivesica s.l. puertodeseadoi, have been reported as dead shells in areas previously covered by Larsen A and B ice shelves (eastern Antarctic Peninsula) and as live animals from active hydrothermal sites in the Kemp Caldera (South Sandwich Arc) at depths of 852–1487 m. Before, A. puertodeseadoi was known only from its type locality in the Argentine Sea, so we considerably extend the range of the species. Observations taken by remotely operated vehicle (ROV) footage show that the clams can live buried in sediment, or epilithically on the surface of rocks in diffuse geothermal flow. Experimental respirometry was conducted at surface pressure on individual bivalves acclimated to either their habitat temperature (4 °C) or elevated temperature (10 °C). The range of standard metabolic rates, from 3.13 to 6.59 (MO2, μmol O2 h−1 g−1 dry tissue mass), is similar to rates measured ex situ for other species in this clade, and rates did not differ significantly between temperature groups. Taken together, these data indicate a range of ecophysiological flexibility for A. puertodeseadoi. Although adapted to a specialist mode of life, this bivalve exploits a relatively broad range of habitats in the Southern Ocean: within sulphidic sediments, epilithically in the presence of diffuse sulphidic flow, or in deep methane-enriched seawater trapped under ice.

scholarly journals From Innate to Adaptive Immune Response in Muscular Dystrophies and Skeletal Muscle Regeneration: The Role of Lymphocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Luca Madaro ◽  
Marina Bouché
Keyword(s):  
Skeletal Muscle ◽  
Immune Response ◽  
Immune Cells ◽  
Current Knowledge ◽  
Adaptive Immune Response ◽  
Inflammatory Cells ◽  
Skeletal Muscle Regeneration ◽  
Current View ◽  
Muscle Necrosis

Skeletal muscle is able to restore contractile functionality after injury thanks to its ability to regenerate. Following muscle necrosis, debris is removed by macrophages, and muscle satellite cells (MuSCs), the muscle stem cells, are activated and subsequently proliferate, migrate, and form muscle fibers restoring muscle functionality. In most muscle dystrophies (MDs), MuSCs fail to properly proliferate, differentiate, or replenish the stem cell compartment, leading to fibrotic deposition. However, besides MuSCs, interstitial nonmyogenic cells and inflammatory cells also play a key role in orchestrating muscle repair. A complete understanding of the complexity of these mechanisms should allow the design of interventions to attenuate MDs pathology without disrupting regenerative processes. In this review we will focus on the contribution of immune cells in the onset and progression of MDs, with particular emphasis on Duchenne muscular dystrophy (DMD). We will briefly summarize the current knowledge and recent advances made in our understanding of the involvement of different innate immune cells in MDs and will move on to critically evaluate the possible role of cell populations within the acquired immune response. Revisiting previous observations in the light of recent evidence will likely change our current view of the onset and progression of the disease.

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