scholarly journals Impact of Dinophysis acuminata Feeding Mesodinium rubrum on Nutrient Dynamics and Bacterial Composition in a Microcosm

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 443 ◽  
Author(s):  
Han Gao ◽  
Chenfeng Hua ◽  
Mengmeng Tong
Keyword(s):  
Bacterial Community ◽  
Nutrient Dynamics ◽  
Environmental Changes ◽  
Prey Availability ◽  
Feeding Activity ◽  
Nutrient Status ◽  
Prey Cell ◽  
Mesodinium Rubrum ◽  
Dinophysis Acuminata ◽  
Study Laboratory

The development of Dinophysis populations, producers of diarrhetic shellfish toxins, has been attributed to both abiotic (e.g., water column stratification) and biotic (prey availability) factors. An important process to consider is mixotrophy of the Dinophysis species, which is an intensive feeding of the Mesodinium species for nutrients and a benefit from kleptochloroplasts. During the feeding process, the nutritional status in the environment changes due to the preference of Mesodinium and/or Dinophysis for different nutrients, prey cell debris generated by sloppy feeding, and their degradation by micro-organisms changes. However, there is little knowledge about the role of the bacterial community during the co-occurrence of Mesodinium and Dinophysis and how they directly or indirectly interact with the mixotrophs. In this study, laboratory experiments were performed to characterize the environmental changes including those of the prey present, the bacterial communities, and the ambient dissolved nutrients during the co-occurrence of Mesodinium rubrum and Dinophysis acuminata. The results showed that, during the incubation of the ciliate prey Mesodinium with its predator Dinophysis, available dissolved nitrogen significantly shifted from nitrate to ammonium especially when the population of M. rubrum decayed. Growth phases of Dinophysis and Mesodinium greatly affected the structure and composition of the bacterial community. These changes could be mainly explained by both the changes of the nutrient status and the activity of Dinophysis cells. Dinophysis feeding activity also accelerated the decline of M. rubrum and contamination of cultures with okadaic acid, dinophysistoxin-1, and pectenotoxin-2, but their influence on the prokaryotic communities was limited to the rare taxa (<0.1%) fraction. This suggests that the interaction between D. acuminata and bacteria is species-specific and takes place intracellularly or in the phycosphere. Moreover, a majority of the dominant bacterial taxa in our cultures may also exhibit a metabolic flexibility and, thus, be unaffected taxonomically by changes within the Mesodinium-Dinophysis culture system.

scholarly journals Collection of Environmental Variables and Bacterial Community Compositions in Marian Cove, Antarctica, during Summer 2018

Data ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 27
Author(s):  
Hyo-Ryeon Kim ◽  
Jae-Hyun Lim ◽  
Ju-Hyoung Kim ◽  
Il-Nam Kim
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Marine Bacteria ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Bacterial Community Composition ◽  
Composition Data ◽  
Decomposition Of Organic Matter ◽  
Class Level ◽  
Earth’S Climate

Marine bacteria, which are known as key drivers for marine biogeochemical cycles and Earth’s climate system, are mainly responsible for the decomposition of organic matter and production of climate-relevant gases (i.e., CO₂, N₂O, and CH₄). However, research is still required to fully understand the correlation between environmental variables and bacteria community composition. Marine bacteria living in the Marian Cove, where the inflow of freshwater has been rapidly increasing due to substantial glacial retreat, must be undergoing significant environmental changes. During the summer of 2018, we conducted a hydrographic survey to collect environmental variables and bacterial community composition data at three different layers (i.e., the seawater surface, middle, and bottom layers) from 15 stations. Of all the bacterial data, 17 different phylum level bacteria and 21 different class level bacteria were found and Proteobacteria occupy 50.3% at phylum level following Bacteroidetes. Gammaproteobacteria and Alphaproteobacteria, which belong to Proteobacteria, are the highest proportion at the class level. Gammaproteobacteria showed the highest relative abundance in all three seawater layers. The collection of environmental variables and bacterial composition data contributes to improving our understanding of the significant relationships between marine Antarctic regions and marine bacteria that lives in the Antarctic.

Selective Bacterial Community Enrichment Between the Pitcher Plants Sarracenia Minor and Sarracenia Flava

2020 ◽  
Author(s):  
Nikolas M. Stasulli ◽  
Scott M. Yourstone ◽  
Ilon Weinstein ◽  
Elizabeth Ademski ◽  
Elizabeth A. Shank
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Prey Availability ◽  
Microbial Community Composition ◽  
Geographic Location ◽  
Rrna Gene ◽  
Natural Ecosystems ◽  
Community Members ◽  
Pitcher Plants ◽  
Naturally Occurring

Abstract BackgroundThe interconnected and overlapping habitats present in natural ecosystems remain a challenge in determining the forces driving microbial community composition. The cup-like leaf structures of some carnivorous plants, including the family Sarraceniaceae, are self-contained ecological habitats that represent systems for exploring such microbial ecology questions. We investigated whether Sarracenia minor and Sarracenia flava, when sampled at the same geographic location and time, cultivate unique microbiota; an indication of biotic selection of microbes due to eliminating many of the environmental variable present in other studies comparing samples harvested over several time points. ResultsDNA was extracted from the decomposing detritus trapped in the base of each Sarracenia leaf pitcher. We profiled a portion of the 16S rRNA gene across the bacterial community members present in this detritus using Illumina MiSeq technology. We identified a surprising amount of diversity within each pitcher, but also discovered that the two Sarracenia species each contained distinct, enriched microbial community members. This suggests a non-random establishment of microbial communities within these two Sarracenia species.ConclusionsOverall, our results indicate that microbial selection is occurring within the pitchers of these two closely related plant species, which is not due to factors such as geographic location, weather, or prey availability. This suggests that specific features of S. minor and S. flava may play a role in fostering specific insect-decomposing microbiomes. These naturally occurring microbial ecosystems can be developed to answer important questions about microbial community succession, disruption, and member contributions to the community. This study will help further establish carnivorous pitcher plants as a model system for studying confined, naturally occurring bacterial communities.

Variation in the diet of the Lataste's viper Vipera latastei in the Iberian Peninsula: seasonal, sexual and size-related effects

2007 ◽  
Vol 57 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Juan Pleguezuelos ◽  
José Brito ◽  
Soumia Fahd ◽  
Xavier Santos ◽  
Gustavo Llorente ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Conservation Management ◽  
Prey Availability ◽  
Feeding Activity ◽  
Prey Type ◽  
Ontogenetic Shift ◽  
Ecological Data ◽  
Opposite Pattern ◽  
Iberian Range ◽  
Ambush Predation

AbstractSeveral life-history traits may increase vulnerability of species to extinction. Among snakes, ambush predation and dietary specialisation are factors that increase this vulnerability. European viper species, genus Vipera, display such traits and are categorised as endangered in several parts of its range. For their conservation management, a deeper knowledge of their ecology and habitat use is highly relevant. One of the species with less ecological data is the Lataste's viper Vipera latastei, a species which lives in the Iberian Peninsula and northwestern Africa. Here, we describe its diet based on the analysis of gut content of 435 museum specimens plus nine bibliographic data from the entire Iberian range. The species showed seasonal and ontogenetic shift in diet but no sexual variations. Feeding activity (percentage of vipers with prey) was low in accordance with its ambush predation tactics, being lower in spring than in summer and autumn. Prey spectrum included two main (reptiles and small mammals), and three sporadic, types of prey (arthropods, amphibians and birds). The consumption of reptiles and mammals was seasonal; the former decreased in occurrence from spring to autumn, whereas the latter showed an opposite pattern. There was an ontogenetic shift in the diet: juveniles fed mainly on reptiles and arthropods, whereas adult vipers progressively substitute this prey with insectivores, and the largest vipers primarily foraged on rodents and birds. Our results suggest that the seasonal variation in prey type was related to prey availability, whereas the ontogenetic shift was linked to gape limitation. The apparently wide prey spectrum of V. latastei must therefore be examined, taking into account that there are seasonal and ontogenetic dietary variations as well as geographic differences, the latter probably driven by climatic contrasts into the Iberian Peninsula. This new data of the endangered Iberian V. latastei can aid the effective conservation management of this species.

The Effects of the Hypsithermal on Prehistoric Foraging Efficiency in Missouri

2005 ◽  
Vol 70 (1) ◽  
pp. 91-106 ◽  
Author(s):  
Steve Wolverton
Keyword(s):  
Environmental Change ◽  
Environmental Changes ◽  
Choice Model ◽  
Prey Availability ◽  
Critical Factor ◽  
Analytical Techniques ◽  
Foraging Theory ◽  
Foraging Efficiency ◽  
Resource Depression ◽  
Human Predation

Archaeological studies of temporal changes in human predation strategy using foraging theory tend to focus on the role of overexploitation of important prey resources and resulting resource depression. An alternative use of the prey-choice model framed under foraging theory is to investigate the influence of environmental changes, such as increases in climate stress, on prey availability. Environmental change can be expected to produce many of the same effects on human predation strategy as resource depression. Here analytical techniques typically used to study the effects of over-predation and resource depression caused by humans are used to monitor their response to fluctuations in prey availability related to climate change during the Holocene in Missouri. Data and interpretations presented here add to the growing body of zooarchaeological foraging theory literature implicating environmental change as a critical factor in human diet.

DairyMod and EcoMod: biophysical pasture-simulation models for Australia and New Zealand

2008 ◽  
Vol 48 (5) ◽  
pp. 621 ◽  
Author(s):  
I. R. Johnson ◽  
D. F. Chapman ◽  
V. O. Snow ◽  
R. J. Eckard ◽  
A. J. Parsons ◽  
...  
Keyword(s):  
New Zealand ◽  
Nutrient Dynamics ◽  
Irrigation Management ◽  
Management Strategies ◽  
Simulation Models ◽  
Nutrient Status ◽  
Pasture Management ◽  
Management Options ◽  
Recent Developments ◽  
Fertiliser Application

DairyMod and EcoMod, which are biophysical pasture-simulation models for Australian and New Zealand grazing systems, are described. Each model has a common underlying biophysical structure, with the main differences being in their available management options. The third model in this group is the SGS Pasture Model, which has been previously described, and these models are referred to collectively as ‘the model’. The model includes modules for pasture growth and utilisation by grazing animals, water and nutrient dynamics, animal physiology and production and a range of options for pasture management, irrigation and fertiliser application. Up to 100 independent paddocks can be defined to represent spatial variation within a notional farm. Paddocks can have different soil types, nutrient status, pasture species, fertiliser and irrigation management, but are subject to the same weather. Management options include commonly used rotational grazing management strategies and continuous grazing with fixed or variable stock numbers. A cutting regime simulates calculation of seasonal pasture growth rates. The focus of the present paper is on recent developments to the management routines and nutrient dynamics, including organic matter, inorganic nutrients, leaching and gaseous nitrogen losses, and greenhouse gases. Some model applications are presented and the role of the model in research projects is discussed.

Soils, crop nutrient status and nutrient dynamics on small-holder farms in central Tibet, China

2011 ◽  
Vol 348 (1-2) ◽  
pp. 219-229 ◽  
Author(s):  
Nicholas G. Paltridge ◽  
Samantha P. P. Grover ◽  
Liu Gouyi ◽  
Jin Tao ◽  
Murray J. Unkovich ◽  
...  
Keyword(s):  
Nutrient Dynamics ◽  
Nutrient Status ◽  
Central Tibet ◽  
Small Holder

scholarly journals Novel feeding and mating behaviors of a population of nautiluses, Nautilus belauensis, in Palau

2019 ◽  
Author(s):  
Gregory J. Barord ◽  
Rebecca L. Swanson ◽  
Peter D. Ward
Keyword(s):  
Behavioral Plasticity ◽  
Environmental Changes ◽  
Prey Availability ◽  
Habitat Type ◽  
Conservation Practices ◽  
Behavioral Differences ◽  
Behavioral Observations ◽  
Mating Behaviors ◽  
Large Living ◽  
Abnormal Behaviors

AbstractThe nautiloid lineage extends back nearly 500 million years but today, is represented by only two living genera, Nautilus and Allonautilus. Behavioral observations of these living nautiluses have improved our understanding of how nautiloids, and ammonoids, behaved and interacted in their environment. These behaviors may also help to inform conservation practices. Here, we describe feeding and mating behaviors in wild nautiluses not reported from any other population. In Palau, Nautilus belauensis was observed actively preying on a large, living crab (Chaceon sp.) and performing courtship-like behaviors prior to mating. These behaviors occurred across multiple nights and from different nautiluses, suggesting that the behaviors are characteristic of at least a subset of the population, if not the entire population. Perhaps the behaviors exhibited by the Palauan nautiluses are an outlier and simply a localized characteristic of a far-removed population. Or, perhaps these apparent abnormal behaviors of Palauan nautiluses are what all nautiluses across the Indo-Pacific should be exhibiting. If the latter explanation is correct, we can start to address the potential causes of the behavioral differences, such as population size, habitat type, and prey availability. In either case, this apparent behavioral plasticity may have also been a reason that the nautiloid lineage has been able to survive throughout millions of years of environmental changes. Today, these behavioral observations could prove to be a valuable conservation tool to protect species and environments, especially in the deep-sea ecosystem the nautiluses inhabit.

scholarly journals Spatio-Temporal Variation in Stable Isotope and Elemental Composition of Key-Species Reflect Environmental changes in the Baltic Sea

2021 ◽  
Author(s):  
Camilla LIENART ◽  
Andrius GARBARAS ◽  
Susanne QVARFORDT ◽  
Jakob WALVE ◽  
Agnes ML Karlson
Keyword(s):  
Stable Isotope ◽  
Baltic Sea ◽  
Elemental Composition ◽  
Nutrient Dynamics ◽  
Environmental Changes ◽  
Nutrient Concentrations ◽  
Food Web Structure ◽  
Open Sea ◽  
Key Species

Abstract Carbon and nitrogen stable isotope ratios are increasingly used to study long-term change in food web structure and nutrient cycling. Whether isotope composition in primary producers and consumers (so-called isotope baselines) reflect environmental changes in a similar manner is largely unknown. We take advantage of long-term oceanographic monitoring data and archived biological samples for the well-studied Baltic Sea to retrospectively analyse elemental composition (C, N and P) and stable isotopes (δ13C, δ15N) in the filamentous ephemeral macroalgae Cladophora spp. and in blue mussel Mytilus edulis trossulus from three contrasting regions (coastal Bothnian Sea and Baltic proper, open sea central Baltic) with the aim to statistically link the observed spatial and interannual (8–24 years’ time-series) variability in elemental and isotope baselines with environmental changes. We find clear differences in isotope baselines between the two major Baltic Sea basins. However, the temporal development in Mytilus δ13C was remarkably similar among regions and, at the open sea station, mussels and algae δ13C also correlated over time, likely reflecting a global Baltic Sea or Northern Hemisphere pattern. In contrast, δ15N of both taxa responded to regional and local drivers (water nutrient concentrations). δ15N in source amino acids allowed detection of diazotrophic N signal in Mytilus, which was masked in bulk δ15N. Finally, Cladophora N:P reflected regional nutrient levels in the water while P %, which differed for both taxa, was linked to food quality for Mytilus. This study highlights the potential of a multi-taxa and multi-stable isotope approach to understand nutrient dynamics and monitor long-term environmental changes.

scholarly journals Changes in Heterotrophic Picoplankton Community Structure after Induction of a Phytoplankton Bloom under Different Light Regimes

Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 195 ◽  
Author(s):  
Karayanni ◽  
Kormas ◽  
Moustaka-Gouni ◽  
Sommer
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Relative Abundance ◽  
Environmental Changes ◽  
Phytoplankton Bloom ◽  
Phytoplankton Growth ◽  
Light Regimes ◽  
Operational Taxonomic Units ◽  
Abundant Otus

Bacterial and archaeal diversity and succession were studied during a mesocosm experiment that investigated whether changing light regimes could affect the onset of phytoplankton blooms. For this, 454-pyrosequencing of the bacterial V1-V3 and archaeal V3-V9 16S rRNA regions was performed in samples collected from four mesocosms receiving different light irradiances at the beginning and the end of the experiment and during phytoplankton growth. In total, 46 bacterial operational taxonomic units (OTUs) with ≥1% relative abundance occurred (22–34 OTUs per mesocosm). OTUs were affiliated mainly with Rhodobacteraceae, Flavobacteriaceae and Alteromonadaceae. The four mesocosms shared 11 abundant OTUs. Dominance increased at the beginning of phytoplankton growth in all treatments and decreased thereafter. Maximum dominance was found in the mesocosms with high irradiances. Overall, specific bacterial OTUs had different responses in terms of relative abundance under in situ and high light intensities, and an early phytoplankton bloom resulted in different bacterial community structures both at high (family) and low (OTU) taxonomic levels. Thus, bacterial community structure and succession are affected by light regime, both directly and indirectly, which may have implications for an ecosystem’s response to environmental changes.

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