Effects of dinoflagellate bioluminescence on the ingestion rates of herbivorous zooplankton

1979 ◽  
Vol 36 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Harris H. White
Keyword(s):  
Ingestion Rates ◽  
Herbivorous Zooplankton

scholarly journals Key considerations for assessing soil ingestion exposures among agricultural workers

2021 ◽  
Author(s):  
Sara N. Lupolt ◽  
Jacqueline Agnew ◽  
Thomas A. Burke ◽  
Ryan David Kennedy ◽  
Keeve E. Nachman
Keyword(s):  
Indirect Measurement ◽  
Agricultural Workers ◽  
Qualitative Investigation ◽  
Soil Ingestion ◽  
Ingestion Rates ◽  
Exposure Science ◽  
Measurement Tools ◽  
Route Of Exposure ◽  
Science Methodology ◽  
Depth Interviews

Abstract Background Soil ingestion is a critical, yet poorly characterized route of exposure to contaminants, particularly for agricultural workers who have frequent, direct contact with soil. Objective This qualitative investigation aims to identify and characterize key considerations for translating agricultural workers’ soil ingestion experiences into recommendations to improve traditional exposure science tools for estimating soil ingestion. Methods We conducted qualitative in-depth interviews with 16 fruit and vegetable growers in Maryland to characterize their behaviors and concerns regarding soil contact in order to characterize the nature of soil ingestion in the agricultural context. Results We identified and discussed four emergent themes: (1) variability in growers’ descriptions of soil and dust, (2) variability in growers’ soil contact, (3) growers’ concerns regarding soil contact, (4) growers’ practices to modify soil contact. We also identified environmental and behavioral factors and six specific agricultural tasks that may impact soil ingestion rates. Significance Our investigation fills an important gap in occupational exposure science methodology by providing four key considerations that should be integrated into indirect measurement tools for estimating soil ingestion rates in the agricultural context. Specifically, a task-based framework may provide a structure for future investigations of soil contact that may be useful in other populations.

The Effect of Temperature and Food Concentration On Ingestion Rates of Quinqueloculina Seminula On the Diatom Nitzschia Closterium

2019 ◽  
Vol 49 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Yanli Lei ◽  
Chengchun Li ◽  
Tiegang Li ◽  
Zhimin Jian
Keyword(s):  
Food Availability ◽  
Ingestion Rate ◽  
Food Concentration ◽  
Laboratory Culture ◽  
Effect Of Temperature ◽  
Clearance Rates ◽  
Organic Detritus ◽  
Local Conditions ◽  
Ingestion Rates ◽  
Nitzschia Closterium

Abstract The majority of sediment-dwelling foraminifera are thought to be deposit feeders. They use their reticulopodia to gather sediment with associated algae, organic detritus, and bacteria. Uptake of diatoms by foraminifera have been observed but rarely quantified. We measured the clearance (gathering) rate and ingestion rate of diatoms by the common benthic foraminifer Quinqueloculina seminula using Nitzschia closterium as prey under laboratory culture conditions. Grazing experiments were performed to evaluate the effects of temperature (at 12, 15, 18, 21, and 24°C) and food availability (10 to 800 cells mm−2) on uptake rates of diatoms. The clearance rates, estimated from the disappearance of food items, were variable (0.59–4.4 mm2 foram−1 h−1) and did not show a clear relationship with food availability. The maximum clearance rates increased from 1.80 ± 0.21 to 2.69 ± 0.32 mm2 foram−1 h−1 when temperature increased from 12 to 18°C and decreased to 2.28 ± 0.25 mm2 foram−1 h−1 at 24°C. Ingestion rates varied from 1.0 to 43 × 103 diatoms foram−1 h−1, following a hyperbolic response to food concentrations at all experimental temperatures. The maximum individual ingestion rates increased from 842 ± 180 to 1648 ± 480 (mean ± SE) cells foram−1 h−1 and then decreased to 316 ± 54 cells foram−1 h−1 as temperature increased from 12 to 24°C. Experimental results revealed that 12–18°C was the optimal temperature range for Q. seminula feeding for specimens adapted to local conditions. Our study indicates that Q. seminula plays an ecological role by feeding upon benthic diatoms in marine benthic ecosystems.

Comparison of four methods to estimate meiobenthic copepod Amonardia normani ingestion rates

2013 ◽  
Vol 160 (9) ◽  
pp. 2395-2404 ◽  
Author(s):  
Lília Pereira de Souza Santos ◽  
Jacques Castel
Keyword(s):  
Ingestion Rates

scholarly journals Interactions Between the Kleptoplastidic Dinoflagellate Shimiella gracilenta and Several Common Heterotrophic Protists

2021 ◽  
Vol 8 ◽  
Author(s):  
Sang Ah Park ◽  
Hae Jin Jeong ◽  
Jin Hee Ok ◽  
Hee Chang Kang ◽  
Ji Hyun You ◽  
...  
Keyword(s):  
Growth Rates ◽  
Ingestion Rate ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Prey Concentration ◽  
Ingestion Rates ◽  
Oxyrrhis Marina ◽  
Planktonic Food ◽  
Moderate Growth ◽  
Algal Prey

The newly described dinoflagellate, Shimiella gracilenta, is known to survive for approximately 1 month on the plastids of ingested prey cells during starvation, indicating kleptoplastidy. To understand the population dynamics of this dinoflagellate in marine planktonic food webs, its growth and mortality rate due to predation should be assessed. Thus, we investigated the feeding occurrence of eight common heterotrophic protists on S. gracilenta. We also determined the growth and ingestion rates of Oxyrrhis marina and the naked ciliate, Rimostrombidium sp. on S. gracilenta as a function of the prey concentration. The common heterotrophic dinoflagellates (HTDs) Gyrodinium dominans, O. marina, and Pfiesteria piscicida and a naked ciliate Rimostrombidium sp. were able to feed on S. gracilenta; whereas the HTDs Aduncodinium glandula, Gyrodinium jinhaense, Oblea rotunda, and Polykrikos kofoidii were not. Shimiella gracilenta supported positive growth of O. marina and Rimostrombidium sp. but did not support that of G. dominans and P. piscicida. With increasing prey concentrations, the growth and ingestion rates of O. marina and Rimostrombidium sp. on S. gracilenta increased and became saturated. The maximum growth rates of O. marina and Rimostrombidium sp. on S. gracilenta were 0.645 and 0.903 day−1, respectively. Furthermore, the maximum ingestion rates of O. marina and Rimostrombidium sp. on S. gracilenta were 0.11 ng C predator day−1 (1.6 cells predator−1 day−1) and 35 ng C predator day−1 (500 cells predator−1 day−1), respectively. The maximum ingestion rate of O. marina on S. gracilenta was lower than that on any other algal prey reported to date, although its maximum growth rate was moderate. In conclusion, S. gracilenta had only a few common heterotrophic protist predators but could support moderate growth rates of the predators. Thus, S. gracilenta may not be a common prey species for diverse heterotrophic protists but may be a suitable prey for a few heterotrophic protists.

scholarly journals Effect of microalgal diets on filtration and ingestion rates of the rotifer Brachionus plicatilis

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Jayasree Loka ◽  
K.K. Philipose ◽  
S.M. Sonali
Keyword(s):  
Filtration Rate ◽  
Brachionus Plicatilis ◽  
Ingestion Rate ◽  
Initial Density ◽  
Isochrysis Galbana ◽  
Nannochloropsis Oculata ◽  
Ingestion Rates ◽  
Significant Difference ◽  
Rotifer Brachionus Plicatilis ◽  
Chaetoceros Calcitrans

Effect of marine microalgal diet on filtration and ingestion rates of Brachionus plicatilis was studied. Marine microalgae viz., Nannochloropsis oculata, Isochrysis galbana, Chaetoceros calcitrans and a combination of N. oculata and I. galbana (Nanno+Iso) at different cell concentrations were selected for the experiment and triplicates were maintained for each feed. Significant difference (p<0.05) was observed in the filtration and ingestion rates of B. plicatilis, between the treatments. Peak filtration rate of 12.2x10-5 cells ml-1 ind-1 min-1 was recorded in B. plicatilis fed with Nanno+Iso, followed by I. galbana. Ingestion rate was found to be significantly high (p<0.05) for those fed with C. calcitrans, followed by Nanno+Iso. Filtration rate was significantly high (p<0.05) in rotifers stocked at an initial density of 50 nos. ml-1 fed with Nanno+Iso. The results indicated that a combination of Nanno and Iso is the best suitable microalgal diet for rotifer with peak filtration (12.2x10-5cells ml-1 ind-1 min-1) and ingestion (5.4x10-3 cells ml-1 ind-1 min-1) rates during the first 60 min.

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