scholarly journals Zooplankton distribution in Mesophotic Corals at Bajo Frijol seamount, Colombian Caribbean

2021 ◽  
Vol 26 (3) ◽  
pp. 281-300
Author(s):  
Laura Contreras Vega ◽  
Alejandro Henao Castr ◽  
Gabriel R Navas S
Keyword(s):  
Water Column ◽  
Relative Abundance ◽  
Food Resource ◽  
Zooplankton Community ◽  
Mesh Size ◽  
Taxonomic Composition ◽  
Mesophotic Coral Ecosystems ◽  
Natural Park ◽  
Three Samples ◽  
Large Groups

Mesophotic coral ecosystems shelter unique communities, but have not been studied enough due to the high cost for the available technologies. The zooplankton have become the primary food resource of the polyps at these environments, due to the low photosynthesis rate of its zooxanthellae, . Therefore, the purpose of this work was to study the zooplankton community associated to the MCEs in Bajo Frijol, in the Corales de Profundidad National Natural Park, and compare its composition with the zooplankton community from shallower parts of the water column. Three samples were taken, filtering 24 L of seawater (45 µm mesh size) at each station with a device designed to collect zooplankton right on top of the reef substrate. The taxonomic composition, density and relative abundance were obtained. A resemblance analysis was performed, complemented with a cluster, an MDS and a modified Kandoorp test. The analysis showed clear differences between the water column samples from those taken close to the reef. It also showed the separation of the community at the seamount into two large groups: north and center-south, both with exclusive species.

scholarly journals Mesozooplankton community development at elevated CO<sub>2</sub> concentrations: results from a mesocosm experiment in an Arctic fjord

2013 ◽  
Vol 10 (3) ◽  
pp. 1391-1406 ◽  
Author(s):  
B. Niehoff ◽  
T. Schmithüsen ◽  
N. Knüppel ◽  
M. Daase ◽  
J. Czerny ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Cold Water ◽  
World Ocean ◽  
Mesh Size ◽  
Co2 Concentration ◽  
Taxonomic Composition ◽  
Marine Biota ◽  
Mesozooplankton Community ◽  
Oithona Similis ◽  
Arctic Fjord

Abstract. The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world ocean. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated CO2 are still lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 μatm to 1420 μatm. Vertical net hauls were taken weekly over about one month with an Apstein net (55 μm mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analysed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (Cirripedia, Polychaeta, Bivalvia, Gastropoda, and Decapoda) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms and the pCO2 had no significant effect on the overall community structure. Also, we did not find significant relationships between the pCO2 level and the abundance of single taxa. Changes in heterogeneous communities are, however, difficult to detect, and the exposure to elevated pCO2 was relatively short. We therefore suggest that future mesocosm experiments should be run for longer periods.

scholarly journals Mesozooplankton community development at elevated CO<sub>2</sub> concentrations: results from a mesocosm experiment in an Arctic fjord

2012 ◽  
Vol 9 (8) ◽  
pp. 11479-11515 ◽  
Author(s):  
B. Niehoff ◽  
N. Knüppel ◽  
M. Daase ◽  
J. Czerny ◽  
T. Boxhammer
Keyword(s):  
Fossil Fuels ◽  
Cold Water ◽  
Mesh Size ◽  
Experimental Period ◽  
Sediment Traps ◽  
Taxonomic Composition ◽  
Marine Biota ◽  
Mesozooplankton Community ◽  
Co2 Concentrations ◽  
Arctic Fjord

Abstract. The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world oceans. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated pCO2 are yet lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 μatm to 1420 μatm. Samples were taken weekly over a six-week period with an Apstein net (55 μm mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analyzed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (cirripeds, polychaetes, bivalves, gastropod, and decapods) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms; the pCO2 had no significant effect on the overall community structure. However, single taxa responded to elevated CO2 concentrations. The ratio of cirripedia nauplii to cypris larvae, the next developmental stage, in the sediment traps averaged over the entire experiment increased with pCO2 and this suggests that increased pCO2 may have delayed their development. Also, the number of bivalves, averaged over the experimental period, decreased significantly with increasing pCO2. The nature of the CO2 effect, either direct or indirect, remains open and needs to be addressed in future.

scholarly journals StrainPro – a highly accurate Metagenomic strain-level profiling tool

2019 ◽  
Author(s):  
Hsin-Nan Lin ◽  
Yaw-Ling Lin ◽  
Wen-Lian Hsu
Keyword(s):  
Microbial Community ◽  
Relative Abundance ◽  
Taxonomic Diversity ◽  
Evaluation Study ◽  
Taxonomic Composition ◽  
Strain Level ◽  
Metagenomic Analysis ◽  
Reference Database ◽  
Analysis Tool ◽  
Analysis Tools

ABSTRACTCharacterizing the taxonomic diversity of a microbial community is very important to understand the roles of microorganisms. Next generation sequencing (NGS) provides great potential for investigation of a microbial community and leads to Metagenomic studies. NGS generates DNA fragment sequences directly from microorganism samples, and it requires analysis tools to identify microbial species (or taxonomic composition) and estimate their relative abundance in the studied community. However, only a few tools could achieve strain-level identification and most tools estimate the microbial abundances simply according to the read counts. An evaluation study on metagenomic analysis tools concludes that the predicted abundance differed significantly from the true abundance. In this study, we present StrainPro, a novel metagenomic analysis tool which is highly accurate both at characterizing microorganisms at strain-level and estimating their relative abundances. A unique feature of StrainPro is it identifies representative sequence segments from reference genomes. We generate three simulated datasets using known strain sequences and another three simulated datasets using unknown strain sequences. We compare the performance of StrainPro with seven existing tools. The results show that StrainPro not only identifies metagenomes with high precision and recall, but it is also highly robust even when the metagenomes are not included in the reference database. Moreover, StrainPro estimates the relative abundance with high accuracy. We demonstrate that there is a strong positive linear relationship between observed and predicted abundances.

scholarly journals Decreased Snow Cover Stimulates Under-Ice Primary Producers but Impairs Methanotrophic Capacity

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Sarahi L. Garcia ◽  
Anna J. Szekely ◽  
Christoffer Bergvall ◽  
Martha Schattenhofer ◽  
Sari Peura
Keyword(s):  
Climate Change ◽  
Snow Cover ◽  
Water Column ◽  
Relative Abundance ◽  
Heterotrophic Bacteria ◽  
Methane Emissions ◽  
Boreal Lakes ◽  
Climate Change Scenarios ◽  
Primary Producers ◽  
Microbial Composition

ABSTRACT Climate change scenarios anticipate decreased spring snow cover in boreal and subarctic regions. Forest lakes are abundant in these regions and substantial contributors of methane emissions. To investigate the effect of reduced snow cover, we experimentally removed snow from an anoxic frozen lake. We observed that the removal of snow increased light penetration through the ice, increasing water temperature and modifying microbial composition in the different depths. Chlorophyll a and b concentrations increased in the upper water column, suggesting activation of algal primary producers. At the same time, Chlorobiaceae, one of the key photosynthetic bacterial families in anoxic lakes, shifted to lower depths. Moreover, a decrease in the relative abundance of methanotrophs within the bacterial family Methylococcaceae was detected, concurrent with an increase in methane concentration in the water column. These results indicate that decreased snow cover impacts both primary production and methane production and/or consumption, which may ultimately lead to increased methane emissions after spring ice off. IMPORTANCE Small lakes are an important source of greenhouse gases in the boreal zone. These lakes are severely impacted by the winter season, when ice and snow cover obstruct gas exchange between the lake and the atmosphere and diminish light availability in the water column. Currently, climate change is resulting in reduced spring snow cover. A short-term removal of the snow from the ice stimulated algal primary producers and subsequently heterotrophic bacteria. Concurrently, the relative abundance of methanotrophic bacteria decreased and methane concentrations increased. Our results increase the general knowledge of microbial life under ice and, specifically, the understanding of the potential impact of climate change on boreal lakes.

scholarly journals Distribusi dan Kemelimpahan Meiofauna di Hulu Sungai Code Yogyakarta

2012 ◽  
Vol 9 (2) ◽  
pp. 34 ◽  
Author(s):  
Riche - Hariyati
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
River Water ◽  
Relative Abundance ◽  
Horizontal Distribution ◽  
Water Current ◽  
Habitat Types ◽  
Chemical Parameter ◽  
Physico Chemical

This research is aimed to study distribution and abundance of meiofauna and the quality of physicochemicalcharacteristics of uppersite of code river and up stream river code Yogyakarta province. Samples weretaken using modified Pysto style corer and were located based on habitat types specific river, which are pool, riffle,rapid, left side and right side of water column. Sample taken four times for each zone. The parameter of for waterquality measured were dissolved oxygen. Water current, alkalinity and pHResult from the analysis showed that the abundance of meiofauna at code river the highest at left side zone.Which was 537.806 individu/m3 with relative abundance was 28,09% result from physico chemical parameter ofdissolved oxygenbetween 5,44 ppm – 6,0 ppm, alkalinity 20 ppm – 25 ppm , pH 7,10 – 7,18.and watercurrenntmeasured between 0,03 m/sec – 0,49 m/sec. The abundance of meiofauna at code river was dominated bygroup of Nematodes horizontal distribution of the fauna was the widest for Nematodes ostracoda, Rhizopoda andinsecta. Physico chemicalquality of code river water was relative good for meiofauna habitat and other waterorganisms

scholarly journals Prey fractionation in the Archaeocyatha and its implication for the ecology of the first animal reef systems

Paleobiology ◽  
2019 ◽  
Vol 45 (4) ◽  
pp. 652-675 ◽  
Author(s):  
Jonathan B. Antcliffe ◽  
William Jessop ◽  
Allison C. Daley
Keyword(s):  
Water Column ◽  
Geographic Distribution ◽  
Feeding Ecology ◽  
Food Resource ◽  
Outer Wall ◽  
Ecological Significance ◽  
Frequency Distributions ◽  
Upper Limits ◽  
Reef Communities ◽  
Modern Reef

AbstractArchaeocyaths are the most abundant sponges from the Cambrian period, having formed the first animal reef communities more than 500 million years ago. The Archaeocyatha are index fossils for correlating rocks of similar ages globally because of their abundance, extensive geographic distribution, detailed anatomy, and well-established taxonomy. Their ecological significance remains incompletely explored, yet they are known to have strongly competitively interacted, unlike modern sponges. This study examines the feeding ecology of the fossil remains of Siberian archaeocyath assemblages. As suspension feeders, archaeocyaths filtered plankton from the water column through pores in their outer wall. Here we outline a new method to estimate the limit on the upper size of plankton that could be consumed by an archaeocyath during life. The archaeocyaths examined were predominantly feeding on nanoplankton and microplankton such as phytoplankton and protozooplankton. Size-frequency distributions of pore sizes from six different Siberian archaeocyath assemblages, ranging from Tommotian to Botoman in age, reveal significantly different upper limits to the prey consumed at each locality. Some of the assemblages contain specimens that could have fed on larger organisms extending into the mesoplankton, including micro-invertebrates as a possible food resource. These results show that during the establishment of the first animal reef systems, prey partitioning was established as a way of reducing competition. This method has applicability for understanding the construction and the functioning of the first reef systems, as well as helping to understand modern reef systems and their development though time and space.

scholarly journals P851 Effects of conservation time on the diversity and relative abundance of intestinal microbiome in samples of faecal matters

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S655-S655
Author(s):  
M León F ◽  
C A Nieto ◽  
Z Corredor ◽  
C Flórez-Sarmiento ◽  
V Parra-Izquierdo ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Relative Abundance ◽  
High Reliability ◽  
Genetic Material ◽  
Variable Region ◽  
Important Variable ◽  
Intestinal Microbiome ◽  
Three Samples ◽  
Stool Samples ◽  
Changes Over Time

Abstract Background Given the complexity and diversity of the intestinal microbiome, there is a technical challenge of finding the best way to study the factors that affect the quality of the sample to obtain results in a precise an complete way. Objective To establish the effect of storage time under constant cryopreservation conditions (−20°C) in stool samples for the study of the gastrointestinal microbiome Methods A sample of stool was distributed in 3 fractions (1, 2 and 3). Time 0 without cryopreservation and immediate DNA extraction (1). The samples of 15 (2) and 30 (3) days were cryopreserved at −20°C before the extraction of the genetic material. After ultracentrifugation at 4 degrees Celsius, the precipitate was subjected to enzymatic and mechanical lysis to obtain the total DNA. The DNA quality was evaluated techniques to ensure the quality and concentration of genetic material. Once the DNA of the three samples was obtained, they were subjected to the latest generation of a variable region of the 16S gene, using MiSeq technology (Illuminates). Data in relative abundances and frequencies were recorded. Project supported by the Administrative Department of Science, Technology and Innovation-Colciencias Health Call 2017, Code 130877757442 Results About 140 thousand readings were obtained for samples 1 (day 0) and 2 (day 15) and 160 thousand for sample 3 (day 30), with a reading quality Q20% between 97 and 98 and Q30% around 94, indicating a high-reliability value for each of the samples. Regarding the classification from the Operating Taxonomic Unit (OTU), 119, 99 and 106 were reported for samples 1, 2 and 3, respectively. The data obtained revealed changes over time at the level of the main edges reported for normal microbiome (Bacteroidetes, Firmicutes, Actinobacteria) between 1 and 2 vs. sample 3. For Firmicutes and Actinobacteria, decreases in abundance of 34% were observed (samples 1 and 2) at 20% for Firmicutes in sample 3 and from 4% (samples 1 and 2) to 0.8% (sample 3) for Actinobacteria. On the contrary, Bacteroidetes presented an increase in its abundance from 58% (Samples 1 and 2) to 76% (sample 3). The Proteobacterium edge did not show significant changes in its abundance Conclusion It was possible to demonstrate that the cryopreservation time before DNA extraction is an important variable that influences the percentage and integrity of the microbiota from faecal matter. Confirming that the maximum reliable shelf life at −20° in stool samples is up to 15 days, suggesting that for longer storage the temperature decrease up to −80° should be taken into account to maintain stability in the results of relative abundance and bacterial diversity

scholarly journals Zooplankton community structure of two marginal lakes of the River Cuiabá (Mato Grosso, Brazil) with analysis of Rotifera and Cladocera diversity

2003 ◽  
Vol 63 (2) ◽  
pp. 329-343 ◽  
Author(s):  
I. F. Neves ◽  
O. Rocha ◽  
K. F. Roche ◽  
A.A. Pinto
Keyword(s):  
Rainy Season ◽  
Zooplankton Community ◽  
Taxonomic Composition ◽  
Domestic Sewage ◽  
Dry Season ◽  
Zooplankton Community Structure ◽  
Keratella Cochlearis ◽  
Mato Grosso ◽  
Littoral Region ◽  
Mato Grosso Do Sul

In the present study, two small lakes on the margins of the River Cuiabá were analyzed regarding taxonomic composition and population densities of the zooplankton. Diversity was evaluated for two groups, Rotifera and Cladocera; sampling was carried out on two dates: 2 March 1999, in the rainy season, and 25 August 1999, in the dry season. Seventy-nine rotifer taxa, 30 cladoceran taxa, and 6 copepod taxa were found. Comparing the species identified in the present study with those recorded by other authors for several water bodies in Mato Grosso and Mato Grosso do Sul states, it was found that 9 species of Cladocera, 2 of Copepoda, and 14 of Rotifera are new records for the region. The most abundant rotifer species were Keratella cochlearis, Brachionus angularis, Polyarthra vulgaris, and Keratella americana. Moina minuta and Bosminopsis deitersi were dominant among the cladocerans, and Notodiaptomus transitans and N. devoyorum among the copepods. Comparing both lakes, the greatest species richness of both Rotifera and Cladocera was observed in Lake Souza Lima, during the rainy season. This is probably linked to the fact that the littoral region of this lake is densely colonized by macrophytes. The lake also has better environmental conditions since it does not receive domestic sewage inputs, as does Lake Parque Atalaia. The diversity of the Rotifera was markedly low in Lake Parque Atalaia, during the dry season, again perhaps linked domestic sewage input found in this water body.

scholarly journals Paleocommunity composition, relative abundance, and new camerate crinoids from the Brechin Lagerstätte (Upper Ordovician)

2020 ◽  
Vol 94 (6) ◽  
pp. 1103-1123 ◽  
Author(s):  
Selina R. Cole ◽  
David F. Wright ◽  
William I. Ausich ◽  
Joseph M. Koniecki
Keyword(s):  
New Species ◽  
Relative Abundance ◽  
Taxonomic Composition ◽  
Nominal Species ◽  
Abundance Distribution ◽  
Upper Ordovician ◽  
Ecological Complexity ◽  
Multiple Resource ◽  
Total Diversity ◽  
Ways Of Life

AbstractThe Brechin Lagerstätte of southern Ontario contains an exceptionally diverse and well-preserved Late Ordovician (Katian) crinoid fauna. We describe four genera and eight species of camerate crinoids from the Brechin Lagerstätte, including six new species. Consequently, the total diversity of the fauna now stands at 27 genera and 39 nominal species, thereby making it the most taxonomically diverse Ordovician crinoid fauna known. Taxa described include the diplobathrid Pararchaeocrinus kiddi new species and the monobathrids Glyptocrinus ramulosus Billings, 1856, Periglyptocrinus priscus (Billings, 1857a), Periglyptocrinus astricus new species, Periglyptocrinus kevinbretti new species, Periglyptocrinus mcdonaldi new species, Periglyptocrinus silvosus new species, and Abludoglyptocrinus steinheimerae new species. We summarize the taxonomic composition, diversity, and abundance distribution of all known crinoids from the Brechin Lagerstätte to better characterize the paleoecological structure and complexity of the community. We establish that the fauna is dominated by the subclass Pentacrinoidea, both in terms of abundance and species richness. In addition, we analyze species-level abundance data using Relative Abundance Distribution (RAD) models to evaluate the ecological complexity of the paleocommunity. We found that community structure of the Brechin Lagerstätte is best explained by an ecologically ‘complex’ RAD model, which suggests that species partitioned niches along multiple resource axes and/or the presence of multiple ecological ways of life. These results indicate that the Brechin Lagerstätte is significant not only for being the most taxonomically diverse Katian crinoid assemblage, but also for being an early ecologically complex fauna that developed in the wake of the Great Ordovician Biodiversification Event.UUID: http://zoobank.org/f86582ed-5db6-469E-befe-34b801f9a113

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