scholarly journals High similarity in the microbiota of cold-water sponges of the Genus Mycale from two different geographical areas

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4935 ◽  
Author(s):  
César A. Cárdenas ◽  
Marcelo González-Aravena ◽  
Alejandro Font ◽  
Jon T. Hestetun ◽  
Eduardo Hajdu ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Cold Water ◽  
Benthic Communities ◽  
Western Antarctic Peninsula ◽  
Total Abundance ◽  
High Similarity ◽  
Significant Component ◽  
Remarkable Similarity ◽  
Magellan Region ◽  
Unique Otus

Sponges belonging to genus Mycale are common and widely distributed across the oceans and represent a significant component of benthic communities in term of their biomass, which in many species is largely composed by bacteria. However, the microbial communities associated with Mycale species inhabiting different geographical areas have not been previously compared. Here, we provide the first detailed description of the microbiota of two Mycale species inhabiting the sub-Antarctic Magellan region (53°S) and the Western Antarctic Peninsula (62–64°S), two geographically distant areas (>1,300 km) with contrasting environmental conditions. The sponges Mycale (Aegogropila) magellanica and Mycale (Oxymycale) acerata are both abundant members of benthic communities in the Magellan region and in Antarctica, respectively. High throughput sequencing revealed a remarkable similarity in the microbiota of both sponge species, dominated by Proteobacteria and Bacteroidetes, with both species sharing more than 74% of the OTUs. In contrast, 16% and 10% of the OTUs were found only in either M. magellanica or M. acerata, respectively. Interestingly, despite slight differences in the relative abundance, the most dominant OTUs were present in both species, whereas the unique OTUs had very low abundances (less than 1% of the total abundance). These results show a significant overlap among the microbiota of both Mycale species and also suggest the existence of a low level of specificity of the most dominant symbiont groups.

scholarly journals A novel design for sampling benthic zooplankton communities in disparate Gulf of Alaska habitats using an autonomous deep-water plankton pump

2020 ◽  
Vol 42 (4) ◽  
pp. 457-466
Author(s):  
Rachel E Wilborn ◽  
Christopher N Rooper ◽  
Pam Goddard ◽  
Kresimir Williams ◽  
Rick Towler
Keyword(s):  
Deep Water ◽  
Cold Water ◽  
Larval Fish ◽  
Low Cost ◽  
Benthic Communities ◽  
Gulf Of Alaska ◽  
Design Parameters ◽  
Benthic Habitat ◽  
Pump Design ◽  
Zooplankton Communities

Abstract Deep-water larval fish and zooplankton utilize structurally complex, cold-water coral and sponge (CWCS) habitats as refuges, nurseries and feeding grounds. Fine-scale sampling of these habitats for larval fish and zooplankton has proven difficult. This study implemented a newly designed, autonomous, noninvasive plankton pump sampler that collected large mesozooplankton within 1 m of the seafloor. It was successfully deployed in the western Gulf of Alaska between the Shumagin Islands (~158°W) and Samalga Pass (−170°W), and collected in situ zooplankton from diverse benthic communities (coral, sponge and bare substrates) at depths in excess of 100 m. Key design parameters of the plankton pump were its ability to be deployed from ships of opportunity, be untethered from the vessel during sampling and be deployed and retrieved in high-relief, rocky areas where CWCS are typically present. The plankton pump remains stationary while collecting from the water column, rests within 1 m of the seafloor and captures images of the surrounding habitat and substrate. This plankton pump design is a low-cost, highly portable solution for assessing the role of benthic habitat in the life cycle of mesozooplankton, a linkage that has been relatively underexplored due to the difficulty in obtaining near-bottom samples.

Comparative physiology of suspension-feeding in living brachiopods and bivalves: evolutionary implications

Paleobiology ◽  
1993 ◽  
Vol 19 (3) ◽  
pp. 322-334 ◽  
Author(s):  
Melissa Clark Rhodes ◽  
R. J. Thompson
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Benthic Communities ◽  
Suspension Feeding ◽  
Metabolic Rates ◽  
Comparative Physiology ◽  
Feeding Rates ◽  
Bivalve Molluscs ◽  
Significant Component ◽  
Experimental Conditions

This paper presents scaling equations relating suspension-feeding rates to body size for articulate brachiopods and bivalve molluscs, two classes which represent a significant component of the fossil record of marine benthic communities. Clearance (feeding) rates of five species of living articulate brachiopods and three species of epifaunal suspension-feeding bivalve molluscs collected from mid-latitude fjords of Newfoundland and New Zealand were measured in similar experimental conditions. In comparisons within and between the two classes, we found that both plectolophous and spirolophous brachiopods had significantly lower feeding rates than mytilids, which are filibranchs, but that a sympatric primitive eulamellibranch veneroid bivalve had rates comparable to the brachiopods. Articulate brachiopods do not appear to feed effectively at the high algal concentrations which bivalves can exploit. The data on comparative suspension-feeding rates support the hypothesis that past changes in diversity and distribution of bivalves and brachiopods may be related to an overall increase in energy flux and escalation of metabolic rates during the Phanerozoic.

scholarly journals Detection of Recombinant Rousettus Bat Coronavirus GCCDC1 in Lesser Dawn Bats (Eonycteris spelaea) in Singapore

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 539
Author(s):  
Adrian C. Paskey ◽  
Justin H. J. Ng ◽  
Gregory K. Rice ◽  
Wan Ni Chia ◽  
Casandra W. Philipson ◽  
...  
Keyword(s):  
Recombinant Virus ◽  
High Throughput Sequencing ◽  
Sampling Time ◽  
Geographical Range ◽  
High Similarity ◽  
Nucleotide Level ◽  
High Prevalence ◽  
Bat Coronavirus ◽  
Targeted Enrichment

Rousettus bat coronavirus GCCDC1 (RoBat-CoV GCCDC1) is a cross-family recombinant coronavirus that has previously only been reported in wild-caught bats in Yúnnan, China. We report the persistence of a related strain in a captive colony of lesser dawn bats captured in Singapore. Genomic evidence of the virus was detected using targeted enrichment sequencing, and further investigated using deeper, unbiased high throughput sequencing. RoBat-CoV GCCDC1 Singapore shared 96.52% similarity with RoBat-CoV GCCDC1 356 (NC_030886) at the nucleotide level, and had a high prevalence in the captive bat colony. It was detected at five out of six sampling time points across the course of 18 months. A partial segment 1 from an ancestral Pteropine orthoreovirus, p10, makes up the recombinant portion of the virus, which shares high similarity with previously reported RoBat-CoV GCCDC1 strains that were detected in Yúnnan, China. RoBat-CoV GCCDC1 is an intriguing, cross-family recombinant virus, with a geographical range that expands farther than was previously known. The discovery of RoBat-CoV GCCDC1 in Singapore indicates that this recombinant coronavirus exists in a broad geographical range, and can persist in bat colonies long-term.

An evaluation of sponge-associated amphipods from the Antarctic Peninsula

2009 ◽  
Vol 21 (6) ◽  
pp. 579-589 ◽  
Author(s):  
Margaret O. Amsler ◽  
James B. Mcclintock ◽  
Charles D. Amsler ◽  
Robert A. Angus ◽  
Bill J. Baker
Keyword(s):  
Antarctic Peninsula ◽  
Energy Flow ◽  
Benthic Communities ◽  
Diversity Indices ◽  
Amphipod Species ◽  
Western Antarctic Peninsula ◽  
Gut Content ◽  
Algal Communities ◽  
Host Relationships ◽  
The Antarctic

AbstractNearshore marine benthic algal communities along the western Antarctic Peninsula harbour extremely high densities of amphipods that probably play important roles in nutrient and energy flow. This study extends our evaluation of the importance of amphipods in the nearshore Antarctic Peninsular benthic communities and focuses on sponge associations. We found a mean density of 542 amphipods per litre (L) sponge for twelve species of ecologically dominant sponges. The highest mean density (1295 amphipods per L sponge) occurred withDendrilla membranosaPallas. The amphipod community associated with the 12 sponges was diverse (38 species), with mean species richness values ranging from two to eight species. Mean Shannon diversity indices (H’) ranged from 0.52 to 1.49. Amphipods did not appear to have obligate host relationships. Qualitative gut content analyses indicated that 12 of the 38 amphipod species were found with sponge spicules in their guts. However, only one of the amphipods,Echiniphimedia hodgsoniWalker, had considerable amounts of spicules in the gut. Organic lipophilic and hydrophilic extracts of the twelve sponges were presented in alginate food disks to a sympatric omnivorous amphipod in feeding bioassays and extracts of only two sponges deterred feeding.

scholarly journals Environmental factors influencing benthic communities in the oxygen minimum zones on the Angolan and Namibian margins

2019 ◽  
Vol 16 (22) ◽  
pp. 4337-4356 ◽  
Author(s):  
Ulrike Hanz ◽  
Claudia Wienberg ◽  
Dierk Hebbeln ◽  
Gerard Duineveld ◽  
Marc Lavaleye ◽  
...  
Keyword(s):  
Organic Matter ◽  
High Temperatures ◽  
Environmental Conditions ◽  
Cold Water ◽  
Benthic Communities ◽  
Benthic Fauna ◽  
Low Oxygen ◽  
Oxygen Minimum Zones ◽  
Oxygen Minimum ◽  
Water Coral

Abstract. Thriving benthic communities were observed in the oxygen minimum zones along the southwestern African margin. On the Namibian margin, fossil cold-water coral mounds were overgrown by sponges and bryozoans, while the Angolan margin was characterized by cold-water coral mounds covered by a living coral reef. To explore why benthic communities differ in both areas, present-day environmental conditions were assessed, using conductivity–temperature–depth (CTD) transects and bottom landers to investigate spatial and temporal variations of environmental properties. Near-bottom measurements recorded low dissolved oxygen concentrations on the Namibian margin of 0–0.15 mL L−1 (≜0 %–9 % saturation) and on the Angolan margin of 0.5–1.5 mL L−1 (≜7 %–18 % saturation), which were associated with relatively high temperatures (11.8–13.2 ∘C and 6.4–12.6 ∘C, respectively). Semidiurnal barotropic tides were found to interact with the margin topography producing internal waves. These tidal movements deliver water with more suitable characteristics to the benthic communities from below and above the zone of low oxygen. Concurrently, the delivery of a high quantity and quality of organic matter was observed, being an important food source for the benthic fauna. On the Namibian margin, organic matter originated directly from the surface productive zone, whereas on the Angolan margin the geochemical signature of organic matter suggested an additional mechanism of food supply. A nepheloid layer observed above the cold-water corals may constitute a reservoir of organic matter, facilitating a constant supply of food particles by tidal mixing. Our data suggest that the benthic fauna on the Namibian margin, as well as the cold-water coral communities on the Angolan margin, may compensate for unfavorable conditions of low oxygen levels and high temperatures with enhanced availability of food, while anoxic conditions on the Namibian margin are at present a limiting factor for cold-water coral growth. This study provides an example of how benthic ecosystems cope with such extreme environmental conditions since it is expected that oxygen minimum zones will expand in the future due to anthropogenic activities.

scholarly journals Macrofauna community inside and outside of the Darwin Mounds SAC, NE Atlantic

2012 ◽  
Vol 9 (11) ◽  
pp. 16907-16932 ◽  
Author(s):  
N. Serpetti ◽  
E. Gontikaki ◽  
B. E. Narayanaswamy ◽  
U. Witte
Keyword(s):  
Cold Water ◽  
Benthic Communities ◽  
Diversity Indices ◽  
Marine Biodiversity ◽  
The European Union ◽  
Ne Atlantic ◽  
Faunal Abundance ◽  
Water Ecosystems ◽  
Macrofaunal Community ◽  
The Impact

Abstract. Over the past two decades, growing concerns have been raised regarding the effects of towed fishing gears, such as trawls and dredges, on deep-sea biodiversity and ecosystem functioning. Trawling disturbs the benthic communities both physically and biologically, and can eliminate the most vulnerable organisms and modify habitat structure; chronically disturbed communities are often dominated by opportunistic species. The European Union is under obligation to designate a network of offshore Special Areas of Conservation (SACs) and Marine Protected Areas (MPAs) by the end of 2012 based on the perceived expectation that these networks will help protect marine biodiversity and that within these areas, faunal abundance and diversity will be higher than the surrounding fished areas. The Darwin Mounds, only discovered in 1998, are located in the Rockall Trough, NE Atlantic at a depth of ~ 1000 m. Deep-water trawling regularly took place in the region of the Darwin Mounds; however in 2004 the mounds were designated as the first offshore SAC in UK and the area is now closed to bottom trawling. As part of the HERMIONE programme the influence of human impact on the Oceans was one of the key themes and in June 2011, an investigation of the macrofaunal community structure at comparable sites both inside and outside of the Darwin Mound SAC was undertaken. Macrofaunal communities were found to differ significantly, with the difference mostly driven by changes in the abundance of polychaetes, crustaceans and nematodes whilst no significant differences were seen for the other phyla. Whereas overall macrofaunal abundance was higher outside the SAC compared to within, this pattern varies considerably between phyla. Diversity indices showed no significant differences between protected and unprotected sites. This could indicate that a few years of preservation are not enough time to determine a recovery by the macrofaunal community of cold-water ecosystems and that a continued monitoring over a longer term is necessary to fully understand the impact of fishery closures.

Effects of sulfamethoxazole on the denitrifying process in anoxic activated sludge and the responses of denitrifying microorganisms

2018 ◽  
Vol 78 (5) ◽  
pp. 1228-1236 ◽  
Author(s):  
Yonglei An ◽  
Xueming Qin
Keyword(s):  
Activated Sludge ◽  
High Throughput Sequencing ◽  
Municipal Wastewater ◽  
Quantitative Polymerase Chain Reaction ◽  
Nitrate Removal ◽  
Alkaline Condition ◽  
Total Abundance ◽  
Effective Inhibition ◽  
Polymerase Chain ◽  
Denitrifying Microorganisms

Abstract The presence of antibiotics in municipal wastewater is bound to affect the anoxic denitrifying process in anoxic activated sludge (AAS). This study investigated the effects of sulfamethoxazole (SMZ) on the denitrifying process in AAS and the responses of denitrifying microorganisms. The results showed that SMZ could decrease the speed of nitrate removal significantly when the concentration of SMZ was lower than 10 mg/L, and the removal of nitrate would be completely inhibited when SMZ concentration was higher than 100 mg/L. Weak alkaline condition would enhance the inhibition effect of SMZ on removal of nitrate in the anoxic bioreactor. The results of high-throughput sequencing and qPCR (quantitative polymerase chain reaction) showed that 100 mg/L of SMZ did not decrease the total abundance of denitrifying microorganisms. However, the relative expression levels of key denitrifying genes NirS and NosZ in AAS treated by 100 mg/L of SMZ versus the raw AAS without SMZ was only 0.030 and 0.036. Therefore, the inhibitory mechanism of SMZ on the denitrifying process in AAS was denoted by an effective inhibition to the expressions of denitrifying genes, rather than a decrease in the total abundance of denitrifying microorganisms.

scholarly journals No barrier to emergence of bathyal king crabs on the Antarctic shelf

2015 ◽  
Vol 112 (42) ◽  
pp. 12997-13002 ◽  
Author(s):  
Richard B. Aronson ◽  
Kathryn E. Smith ◽  
Stephanie C. Vos ◽  
James B. McClintock ◽  
Margaret O. Amsler ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Cold Water ◽  
Austral Summer ◽  
Outer Shelf ◽  
Depth Range ◽  
Western Antarctic Peninsula ◽  
Near Surface ◽  
Viable Population ◽  
Gravid Females ◽  
The Antarctic

Cold-water conditions have excluded durophagous (skeleton-breaking) predators from the Antarctic seafloor for millions of years. Rapidly warming seas off the western Antarctic Peninsula could now facilitate their return to the continental shelf, with profound consequences for the endemic fauna. Among the likely first arrivals are king crabs (Lithodidae), which were discovered recently on the adjacent continental slope. During the austral summer of 2010‒2011, we used underwater imagery to survey a slope-dwelling population of the lithodid Paralomis birsteini off Marguerite Bay, western Antarctic Peninsula for environmental or trophic impediments to shoreward expansion. The population density averaged ∼4.5 individuals × 1,000 m−2 within a depth range of 1,100‒1,500 m (overall observed depth range 841–2,266 m). Images of juveniles, discarded molts, and precopulatory behavior, as well as gravid females in a trapping study, suggested a reproductively viable population on the slope. At the time of the survey, there was no thermal barrier to prevent the lithodids from expanding upward and emerging on the outer shelf (400- to 550-m depth); however, near-surface temperatures remained too cold for them to survive in inner-shelf and coastal environments (<200 m). Ambient salinity, composition of the substrate, and the depth distribution of potential predators likewise indicated no barriers to expansion of lithodids onto the outer shelf. Primary food resources for lithodids—echinoderms and mollusks—were abundant on the upper slope (550–800 m) and outer shelf. As sea temperatures continue to rise, lithodids will likely play an increasingly important role in the trophic structure of subtidal communities closer to shore.

scholarly journals Warm Temperatures, Cool Sponges: The Effect of Increased Temperatures on the Antarctic Sponge Isodictya sp

2018 ◽  
Author(s):  
M. González-Aravena ◽  
N.J. Kenny ◽  
M. Osorio ◽  
A. Font ◽  
A. Riesgo ◽  
...  
Keyword(s):  
Thermal Stress ◽  
De Novo ◽  
Cold Water ◽  
Western Antarctic Peninsula ◽  
Sres Scenarios ◽  
Ipcc Sres ◽  
The Antarctic ◽  
Sessile Organisms ◽  
Water Species ◽  
Cold Water Species

AbstractAlthough the cellular and molecular responses to exposure to relatively high temperatures (acute thermal stress or heat shock) have been studied previously, only sparse empirical evidence of how it affects cold-water species is available. As climate change becomes more pronounced in areas such as the Western Antarctic Peninsula, it has become crucial to understand the capacity of these species to respond to thermal stress.Here we use the Antarctic sponge Isodictya sp. to investigate how sessile organisms (particularly Porifera) can adjust to acute short-term heat stress, by exposing this species to 3 and 5 °C for 4 hours, corresponding to predicted temperatures under high-end 2080 IPCC-SRES scenarios. Assembling a de novo reference transcriptome (90,188 contigs, >93.7% metazoan BUSCO genes) we have begun to discern the molecular componentry employed by Isodictya to adjust to environmental insult.Our initial analyses suggest that TGF-β, ubiquitin and hedgehog cascades are involved, alongside other genes. However, the degree and type of response changed little from 3 to 5 °C, suggesting that even moderate rises in temperature could cause stress at the limits of this organism’s capacity. Given the importance of sponges to Antarctic ecosystems, our findings are vital for discerning the consequences of increases in Antarctic ocean temperature on these and other species.

scholarly journals Abundance and spatial distribution of neustonic copepodits of Microsetella rosea (Harpacticoida: Ectinosomatidae) along the western Magellan coast, southern Chile

2017 ◽  
Vol 44 (3) ◽  
pp. 576-587
Author(s):  
Juan I. Cañete ◽  
Carlos S. Gallardo ◽  
Carlos Olave ◽  
María S. Romero ◽  
Tania Figueroa ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Population Biology ◽  
Harpacticoid Copepod ◽  
Future Research ◽  
Total Abundance ◽  
Southern Chile ◽  
Sampling Area ◽  
Ecological Functions ◽  
Magellan Region ◽  
Oceanographic Conditions

The pelagic harpacticoid copepod Microsetella rosea inhabits the cold waters along the temperate southern coast of Chile, where its population biology and ecological role in the neuston are unknown. During a CIMAR 16 Fiordos cruise realized in the Magellan Region, 26 neustonic samples were collected to analyze the abundance, spatial distribution of copepodits and oceanographic conditions (temperature, salinity, and dissolved oxygen). M. rosea copepodits, the most abundant holoneustonic taxa (30% of total abundance), were present at all sampled stations and were 0.5 times more abundant than calanoids. These copepodits inhabited waters ranging between 6.5-8.5°C and salinity of 26-33, with maximum abundances (1,000-10,000 ind/5 min horizontal drag) at means of 7.2 ± 0.6ºC and salinities of 30.7 ± 0.9. Froward Cape, Almirantazgo Sound, and Inútil Bay stations accounted for 65% of total M. rosea abundance, whereas Beagle Channel stations present the lowest abundances (<4%). The entire sampling area was as an oxygenated estuary (7.4 ± 0.4 mL L-1). Given the abundance and recurrence of M. rosea in the Magellanic neuston, future research should assess the ecological functions of this species. Finally, M. rosea could also be used as a biotracer for processes of aggregation in other estuarine neustonic communities of southern Chile.

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