scholarly journals Respiration Rates, Metabolic Demands and Feeding of Ephyrae and Young Medusae of the Rhizostome Rhopilema nomadica

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 320
Author(s):  
Zafrir Kuplik ◽  
Dani Kerem ◽  
Dror L. Angel
Keyword(s):  
Eastern Mediterranean ◽  
Oxygen Demand ◽  
Bell Diameter ◽  
Feeding Rates ◽  
Marine Food Web ◽  
Respiration Rates ◽  
Dietary Requirements ◽  
Multiple Measurements ◽  
Feeding Trials ◽  
Marine Food

Jellyfish (cnidarians and ctenophores) affect the marine food web through high feeding rates and feeding efficiency, but in contrast to their great importance in the ecosystem, our knowledge of their dietary requirements is limited. Here we present the results of respiratory and feeding trials of the rhizostome Rhopilema nomadica, the dominant scyphozoan in the waters of the Eastern Mediterranean, which often establishes massive swarms, mainly in the summer months. Through multiple measurements of oxygen demand in R. nomadica at bell diameters of 3–49 mm, we were able to assess its minimum energetic requirements. These, and the results of the feeding trials on individuals of the same bell diameter range, show that R. nomadica is a very efficient predator. When presented with prey concentrations of 100 prey items per liter, a single hourly feeding session provided between 1.15 and 3 times the estimated daily basal carbon requirement. Our findings suggest that R. nomadica is well adapted to its environment, the hyperoligotrophic waters of the eastern Mediterranean, able to efficiently exploit patches of plankton, possibly at rates even higher than what we observed under laboratory conditions.

scholarly journals Diet composition and some observations on the feeding ecology of the rhizostome Rhopilema nomadica in Israeli coastal waters

2020 ◽  
Vol 100 (5) ◽  
pp. 681-689
Author(s):  
Z. Kuplik ◽  
D. L. Angel
Keyword(s):  
Ecosystem Services ◽  
Feeding Ecology ◽  
Coastal Waters ◽  
Diet Composition ◽  
Gut Contents ◽  
Bell Diameter ◽  
Marine Food Web ◽  
Marine Food ◽  
Potential Impact ◽  
Predatory Pressure

AbstractSince the mid-1980s, swarms of the rhizostome Rhopilema nomadica have been an annual phenomenon in Israeli Mediterranean coastal waters during the summer months. Despite its annual prominence and the potential impact on food webs and ecosystem services, studies concerning its feeding ecology and its interactions with other biota in the marine food web have not been conducted. During summer 2015 gut contents of 41 R. nomadica were analysed as well as ambient plankton assemblages. More than 60% of the medusae diet was found to consist of microzooplankton <150 μm. Size correlations revealed that larger R. nomadica consumed faster swimming prey while smaller medusae relied more on the slower swimming taxa. The medusan diet reflected most of the ambient plankton taxa, but no statistically significant correlations between the relative abundance in diet and ambient plankton were found. As summer progressed, there was a gradual decrease in both mean medusa bell diameter (from 42.2–16 cm) and integrity of feeding structures. These findings suggest that R. nomadica, at least at the time of its appearance in Israeli coastal waters, may exert less predatory pressure on the plankton than we might otherwise expect.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals Complexities of disturbance response in a marine food web

2021 ◽  
Author(s):  
Kristy A. Lewis ◽  
Robert R. Christian ◽  
Charles W. Martin ◽  
Kira L. Allen ◽  
Ashley M. McDonald ◽  
...  
Keyword(s):  
Food Web ◽  
Marine Food Web ◽  
Disturbance Response ◽  
Marine Food

The Role of Ammonites in the Mesozoic Marine Food Web Revealed by Jaw Preservation

Science ◽  
2011 ◽  
Vol 331 (6013) ◽  
pp. 70-72 ◽  
Author(s):  
I. Kruta ◽  
N. Landman ◽  
I. Rouget ◽  
F. Cecca ◽  
P. Tafforeau
Keyword(s):  
Food Web ◽  
Marine Food Web ◽  
Marine Food

scholarly journals Inter-annual cascade effect on marine food web: A benthic pathway lagging nutrient supply to pelagic fish stock

PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0184512 ◽  
Author(s):  
Lohengrin Dias de Almeida Fernandes ◽  
Eduardo Barros Fagundes Netto ◽  
Ricardo Coutinho ◽  
Keyword(s):  
Food Web ◽  
Nutrient Supply ◽  
Pelagic Fish ◽  
Fish Stock ◽  
Marine Food Web ◽  
Cascade Effect ◽  
Marine Food

Trophic transfer of heavy metals in the marine food web based on tissue residuals

2021 ◽  
Vol 772 ◽  
pp. 145064
Author(s):  
Yongfei Gao ◽  
Ruyue Wang ◽  
Yanyu Li ◽  
Xuebin Ding ◽  
Yueming Jiang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Food Web ◽  
Trophic Transfer ◽  
Web Based ◽  
Marine Food Web ◽  
Marine Food

Phytoplankton in the embayments of King George Island (Antarctic Peninsula): a review with emphasis on diatoms

Polar Record ◽  
2018 ◽  
Vol 54 (2) ◽  
pp. 158-175 ◽  
Author(s):  
Priscila Kienteca Lange ◽  
Ryszard Ligowski ◽  
Denise Rivera Tenenbaum
Keyword(s):  
Antarctic Peninsula ◽  
Early Summer ◽  
Western Antarctic Peninsula ◽  
King George Island ◽  
Accurate Identification ◽  
Phytoplankton Assemblages ◽  
Marine Food Web ◽  
Planktonic Diatoms ◽  
Local Material ◽  
Marine Food

ABSTRACTConsidering that phytoplankton assemblages are good bioindicators of environmental conditions, the sensitivity of the Western Antarctic Peninsula (WAP) to climate change, and the importance of some areas of its islands as Antarctic Specially Managed Areas, this work assembles published datasets on phytoplankton biodiversity and ecology in confined coastal areas (embayments) of King George Island, WAP. Over 33 years (1980–2013), 415 species from 122 genera have been identified to species level, being mostly diatoms (371 species), with 10 new species described with local material (6 diatoms, 4 cyanobacteria). The importance of diatoms was indicated by the frequent occurrence of Corethron pennatum, Pseudogomphonema kamtshaticum, and abundant benthic genera in the plankton (e.g. Navicula, Cocconeis). The increased contribution of dinoflagellates after 2010 suggests marked changes in the water column. Early-summer blooms differ between the bays' eastern and western shores, with terrestrial melting and wind-driven upwelling inducing the dominance of benthic species at eastern shores, whereas planktonic diatoms (Thalassiosira, Pseudo-nizschia, and Chaetoceros) are most abundant along western shores and central areas. The importance of an accurate identification of organisms that are becoming key ecological components of the region is discussed, as recent changes in the microflora may affect the entire marine food web.

scholarly journals Time-since-invasion increases native mesoherbivore feeding rates on the invasive alga, Sargassum muticum (Yendo) Fensholt

2017 ◽  
Vol 98 (8) ◽  
pp. 1935-1944 ◽  
Author(s):  
Martyn Kurr ◽  
Andrew J. Davies
Keyword(s):  
Invasive Plants ◽  
Enemy Release Hypothesis ◽  
Sargassum Muticum ◽  
Enemy Release ◽  
Feeding Rates ◽  
Herbivore Species ◽  
Feeding Trials ◽  
Negative Impacts ◽  
Abundance And Diversity ◽  
Invasive Alga

Invasive algae can have substantial negative impacts in their invaded ranges. One widely cited mechanism that attempts to explain how invasive plants and algae are often able to spread quickly, and even become dominant in their invaded ranges, is the Enemy Release Hypothesis. This study assessed the feeding behaviours of two species of gastropod herbivore from populations exposed to the invasive alga Sargassum muticum for different lengths of time. Feeding trials, consisting of both choice and no-choice, showed that the herbivores from older stands (35–40 years established) of S. muticum were more likely to feed upon it than those taken from younger (10–19 years established) stands. These findings provide evidence in support of the ERH, by showing that herbivores consumed less S. muticum if they were not experienced with it. These findings are in accordance with the results of other feeding-trials with S. muticum, but in contrast to research that utilizes observations of herbivore abundance and diversity to assess top-down pressure. The former tend to validate the ERH, and the latter typically reject it. The potential causes of this disparity are discussed, as are the importance of palatability, herbivore species and time-since-invasion when considering research into the ERH. This study takes an important, yet neglected, approach to the study of invasive ecology.

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