scholarly journals Attachment of the peritrich epibiont Zoothamnium intermedium Precht, 1935 (Ciliophora, Peritrichia) to artificial substrates in a natural environment

2008 ◽  
Vol 68 (4) ◽  
pp. 795-798 ◽  
Author(s):  
LRP. Utz
Keyword(s):  
Chesapeake Bay ◽  
Natural Environment ◽  
Acartia Tonsa ◽  
Artificial Substrates ◽  
Copepod Species ◽  
Field Observations ◽  
Marine Environments ◽  
Eurytemora Affinis ◽  
Free Swimming ◽  
Living Organisms

Peritrich ciliates are commonly found as epibionts, colonizing living organisms, or attached to non-living substrates in freshwater, estuarine and marine environments. Several species of peritrich epibionts are obligate, which means that they are able to only colonize other organisms, while others are facultative attaching to living or non-living substrates. The peritrich Zoothamnium intermedium is commonly found as epibiont on the copepod species Acartia tonsa and Eurytemora affinis in Chesapeake Bay, USA. Previous studies demonstrated that Z. intermedium is not able to attach to non-living substrates in the laboratory; with free-swimming stages (telotrochs) dying when living substrates are not available for colonization. The present study investigated the ability of Z. intermdium to colonize artificial substrates in the field. Observations were carried out while the peritrich ciliate was colonizing copepods in Rhode River, a tributary of Chesapeake Bay. Results demonstrated that four species of Zoothamnium were recovered from artificial substrates, but none of them was Z. intermedium. At the same time, Z. intermedium was colonizing adults and copepodites of E. affinis and A. tonsa during the whole study period. These results, in addition to laboratory observations, suggest that Z. intermedium is an obligate epibiont.

scholarly journals Association of Vibrio cholerae O1 El Tor and O139 Bengal with the Copepods Acartia tonsa and Eurytemora affinis

2007 ◽  
Vol 73 (24) ◽  
pp. 7926-7933 ◽  
Author(s):  
Tonya K. Rawlings ◽  
Gregory M. Ruiz ◽  
Rita R. Colwell
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Acartia Tonsa ◽  
Copepod Species ◽  
Life Stages ◽  
Eurytemora Affinis ◽  
Rural Bangladesh ◽  
Laboratory Microcosm ◽  
Vibrio Cholerae O1 ◽  
El Tor

ABSTRACT The association of Vibrio cholerae with zooplankton has been suggested as an important factor in transmission of human epidemic cholera, and the ability to colonize zooplankton surfaces may play a role in the temporal variation and predominance of the two different serogroups (V. cholerae O1 El Tor and O139) in the aquatic environment. To date, interactions between specific serogroups and species of plankton remain poorly understood. Laboratory microcosm experiments were carried out to compare quantitatively the colonization of two copepod species, Acartia tonsa and Eurytemora affinis, by each of the epidemic serogroups. V. cholerae O1 consistently achieved higher abundances than V. cholerae O139 in colonizing adults of each copepod species as well as the multiple life stages of E. affinis. This difference in colonization may be significant in the general predominance of V. cholerae O1 in cholera epidemics in rural Bangladesh where water supplies are taken directly from the environment.

Microbe-Worm Symbiosis Stabilizes Methane Hydrates in Deep Marine Environments

2021 ◽  
Author(s):  
Tianyi Hua ◽  
Maisha Ahmad ◽  
Tenzin Choezin ◽  
Ryan Hartman
Keyword(s):  
Methane Hydrate ◽  
Temperature Fluctuations ◽  
Methane Hydrates ◽  
Natural Ecosystem ◽  
Ocean Temperature ◽  
Marine Environments ◽  
Balance Equations ◽  
Temperature Records ◽  
Living Organisms ◽  
Hydrate Stability

Abstract Our Planet has a natural ecosystem comprised of living organisms and methane hydrates in deep marine environments. This ecosystem was constructed in the present work to examine the influence that subtle temperature fluctuations could have on the dynamic stability of the hydrate deposits. The coupled mass and energy balance equations that describe the microbial bioreactions, their consumption by feather duster worms, and methane hydrate dissociation confirm that the bioreaction kinetics are dominated by endothermic methanogenic metabolism that stabilizes methane hydrates with a fragile tolerance to 0.001K temperature increases. The feather duster worms also stabilize the hydrates via their selective consumption of methanotrophs that could otherwise overtake the system by their exothermic metabolism. Critical ocean temperature limits exist, beyond which hydrate dissociations would cause underwater eruptions of methane into the sea. Historical ocean temperature records and gas hydrate inventory estimates combined with our model suggests that hydrate deposits as deep as 560-meters below sea level could already be at risk, whereas the methane hydrate stability zone will retreat deeper as ocean temperatures rise. Slowing its retreat could avoid the massive release of greenhouse gas.

scholarly journals Key Drivers for Copepod Assemblages in a Eutrophic Coastal Brackish Lake

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 363 ◽  
Author(s):  
Neila Annabi-Trabelsi ◽  
Gamal El-Shabrawy ◽  
Mohamed E. Goher ◽  
Madhavapeddi N. V. Subrahmanyam ◽  
Yousef Al-Enezi ◽  
...  
Keyword(s):  
Nile Delta ◽  
Acartia Tonsa ◽  
Copepod Species ◽  
Indigenous Species ◽  
Coastal Lake ◽  
Brackish Lake ◽  
Identification Of Species ◽  
Key Drivers ◽  
Non Indigenous Species ◽  
First Time

The copepod assemblages and abiotic parameters were investigated at 11 stations in a large coastal lake (Lake Manzalah, Nile Delta) from 2009–2010 in order to verify any impacts of eutrophication and salinity on the copepod species composition. The environmental conditions and the copepod assemblages appeared to have changed in comparison with previous studies, possibly because of increasing eutrophication and invasions of non-indigenous species (NIS). The aim of the present study was the identification of species which can be used as ecological indicators of high trophic status. Among the nine copepod species of Lake Manzalah, Acartia tonsa, Mesocyclops ogunnus, and Apocyclops panamensis were reported for the first time. Acartia tonsa, a well-known NIS for the Mediterranean, numerically dominated the copepod assemblages in some portions of the lake. The distribution of Acanthocyclops trajani and Thermocyclops consimilis was insensible to eutrophication because they can stand high levels of nutrients and hypoxia. Compared with previous reports, the copepod assemblage of Lake Manzalah was richer in species. The invasions of NIS, in addition to the heterogeneous progress of eutrophication in the lake, created an environmental mosaic with many species in total, but with single areas suitable for only a small number of them.

Selective feeding of Eurytemora affinis (Copepoda, Calanoida) in temperate estuaries: model and field observations

2003 ◽  
Vol 56 (2) ◽  
pp. 305-311 ◽  
Author(s):  
M.L.M Tackx ◽  
P.J.M Herman ◽  
S Gasparini ◽  
X Irigoien ◽  
R Billiones ◽  
...  
Keyword(s):  
Field Observations ◽  
Selective Feeding ◽  
Eurytemora Affinis

scholarly journals A Case Study of the Exotic Poisonous Plants found in Kottayam District, Kerala, India

2020 ◽  
Vol 2 (4) ◽  
pp. 1-12
Author(s):  
Binu Thomas ◽  
Vrunda Vasudev
Keyword(s):  
Exotic Plants ◽  
Plant Part ◽  
Field Observations ◽  
Poisonous Plants ◽  
Number Of Species ◽  
Extensive Field ◽  
Different Types ◽  
Living Organisms

Poisonous plants contain many harmful biological components which can be dangerous for living organisms upon contact or due to ingestion. The current study is based on extensive field observations aimed to find out the various exotic poisonous plants in the Meenachil Taluk of Kottayam District, Kerala. A total of 19 exotic plants belonging to 10 families and 18 genera were documented. Among these, Apocynaceae and Euphorbiaceae were dominant in terms of the number of species with 5 species each. Moreover, the authors also verified the nativity of these plants. The various plant part(s) such as bark, stem, leaves, fruits, latex, and tuber were found to have different types of poisonous compounds. The severity of the illness caused due to these plants and their respective parts depends on the dose in which the organisms ingest their components or the extent to which they make contact with them. People should be aware about such poisonous plants for avoiding various complications.

scholarly journals Development of the Characterizing Indicators for the Existing Biodiversity and Natural Ecosystems and Their Role in Habitat Formation

2019 ◽  
Vol 105 ◽  
pp. 02009 ◽  
Author(s):  
Alexander Myaskov ◽  
Svetlana Kostyuk ◽  
Dora Marinova
Keyword(s):  
Environmental Policy ◽  
Natural Environment ◽  
Biological Diversity ◽  
Biological Species ◽  
Environmental Condition ◽  
Human Beings ◽  
Natural Ecosystems ◽  
Economic Decisions ◽  
Living Organisms ◽  
Specific Species

Particular species of living organisms contribute to our natural environment in respective particular ways. Joined together, these species form biocenoses, able to run vital natural functions. Biogeocenoses that tightly link living and non-living organisms are the basis of ecosystems, our planet and human beings as biological species in particular, as later ones are fully dependent on the environmental condition. Determining the contributions of specific species and, subsequently, ecosystems is an essential aspect of human environmental policy. Determining the importance and value of biological diversity as well as understanding of its existence is a mandatory element of environmental policy of major industrial corporations and the basis of future economic decisions of all countries.

Self-evolving materials based on metastable-to-stable crystal transition of polymorphic polyolefin

2022 ◽  
Author(s):  
Wenhua Yuan ◽  
Chengtao Yu ◽  
Shanshan Xu ◽  
Lingling Ni ◽  
Wenqing Xu ◽  
...  
Keyword(s):  
Structural Transformation ◽  
Natural Environment ◽  
Crystal Transition ◽  
The Common ◽  
Living Organisms ◽  
Non Equilibrium

Living organisms can self-evolve with time in order to adapt to natural environment. Analogically, self-evolving materials also show similar properties based on a non-equilibrium structural transformation. The common design of...

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