Predation by three glacial opportunists on natural zooplankton communities

1986 ◽  
Vol 64 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Redwood W. Nero ◽  
W. Gary Sprules
Keyword(s):  
Previous Survey ◽  
Clearance Rates ◽  
Mysis Relicta ◽  
Chydorus Sphaericus ◽  
Theoretical Comparison ◽  
Feeding Experiments ◽  
Predatory Impact ◽  
Limnocalanus Macrurus ◽  
Zooplankton Communities

We examine the influence of three glacial opportunist predators, Mysis relicta, Limnocalanus macrurus, and Senecella calanoides, on natural zooplankton communities of central Ontario through a series of feeding experiments in small enclosures (23.6 L). Estimates of in situ clearance rates by M. relicta match previously determined rates, with the following gradation of values: Asplanchna sp. > daphnids and bosminids > Epischura lacustris > large cyclopoids, Chydorus sphaericus and small Diaptomus sp. > L. macrurus > S. calanoides. Clearance rates by M. relicta are similar for all daphnids and bosminids. Hypolimnetic species like Daphnia longiremis and Eubosmina longispina are apparently eliminated by M. relicta, while similarly vulnerable species survive because they have an epilimnetic refuge from M. relicta. Limnocalanus macrurus and S. calanoides prey primarily on copepods, Diaphanosoma spp., and rotifers in the hypolimnion. When both clearance rates and population densities of M. relicta, L. macrurus, and S. calanoides are taken into account, the total predatory impact of M. relicta is much larger than that of the two relict copepods. Based on a theoretical comparison of measured clearance rates by predators with estimated rates of prey recruitment, we conclude that differences in species composition and abundance between relict and nonrelict lakes described in a previous survey are due principally to predation by M. relicta.

Environmental Factors Affecting Predation Rates of Mysis relicta

1982 ◽  
Vol 39 (1) ◽  
pp. 203-208 ◽  
Author(s):  
Scott D. Cooper ◽  
Charles R. Goldman
Keyword(s):  
Feeding Rate ◽  
Bright Light ◽  
Time Of Day ◽  
Clearance Rates ◽  
Mysis Relicta ◽  
Factors Affecting ◽  
Feeding Experiments ◽  
Opossum Shrimp ◽  
Consumption Rates ◽  
Low Levels

Mysis relicta was fed Epischura nevadensis late instars or Diaptomus tyrrelli males in a series of feeding experiments. Mysis clearance rates were not affected by the time of day mysids were collected, the time of day experiments were conducted, or conditioning of experimental water by predators and prey. Mysis fed as efficiently in the dark as in bright light, and exhibited increasing clearance rates with increasing container size. When Diaptomus males were used as prey Mysis clearance rates were significantly higher at 5 °C than 10 and 15 °C; temperature did not affect clearance rates with Epischura as prey. Mean clearance rates tended to decline with increasing prey density, but the only significant differences were recorded when Epischura was used as prey. Prior acclimation to experimental light and temperature conditions had no effect on the results. When presented with an abundant food supply, freshly collected Mysis fed at initially low rates. Subsequent feeding rate peaks were followed by feeding rate declines to low levels over a 24-h period. Individual Mysis consumption rates remained relatively constant from day to day.Key words: Mysis relicta, predation, copepods, clearance rates, opossum shrimp

Feeding experiments of the seep-associated foraminifer Nonionellina labradorica with a marine methanotroph from the Arctic

2021 ◽  
Author(s):  
Christiane Schmidt ◽  
Geslin Emmanuelle ◽  
Bernhard Joan M. ◽  
LeKieffre Charlotte ◽  
Roberge Helene ◽  
...  
Keyword(s):  
Barents Sea ◽  
Feeding Habits ◽  
The Arctic ◽  
Type I ◽  
Intracytoplasmic Membrane ◽  
Organic Detritus ◽  
Feeding Experiments ◽  
Food Vacuoles ◽  
Species Specific

<p>Foraminifera on the seafloor are known to have species-specific feeding habits. Among those are deposit feeders, eating organic detritus and bacteria. Little is known about the feeding habits of foraminifera from Arctic seep environments. That is, in particular, of interest as variable δ<sup>13</sup>C values in the tests of foraminifera have been suggested to be partly linked with a diet rich in bacteria, themselves lighter in δ<sup>13</sup>C values. As there is little information on the ecology of the foraminifer <em>Nonionellina labradorica</em> (Dawson, 1860), this study examined feeding habits on bacteria and compared them to in situ collected specimens, using Transmission Electron microscopy (TEM). As bacterial food, the marine methane-oxidizing bacterium <em>Methyloprofundus sedimenti</em> was chosen, which is an important representative of methanotrophs in the marine environment near methane seeps. Sediment samples containing living N. labradorica specimens collected in close vicinity(approx. 5 m) from an active methane seep in Storfjordrenna, Barents Sea (382-m water depth).  We performed a feeding experiment on <em>N. labradorica </em>(n=17 specimen), which were incubated in the dark at in situ temperature. Specimens were fed at the beginning of the experiment, except the un-fed controls, and incubations terminated after 4, 8 and 20 h. After fixation in epoxy resin the ultrastructure of all specimens and their food vacuoles was observed and compared using a TEM. All examined specimens were living at the time of fixation, based on observation of intact mitochondrial membranes. In all specimens, inorganic detritus was preserved inside food vacuoles. Closer observation of food vacuoles also revealed that in addition to inorganic debris, such as clay, occasionally bacteria were visible. This led us to conclude that our <em>N. labradorica </em>can  generally be classified as a deposit feeder, which is rather a generalist than a specialist. Regarding uptake of <em>M. sedimenti</em>, the timing of the experimentation seemed to be critical. We did not observe methanotrophs preserved in the resin at the 4 and 8 h incubations, but found two putative methanotrophs near the apertural region after the 20-h incubation. After closer observation, we could identify one of those two putative specimen as the menthanothroph <em>M. sedimenti</em> near the foraminiferal aperture, based on presence of a typical type I stacked intracytoplasmic membrane (ICM) and storage granules (SC). We concluded that <em>N. labradorica</em> may ingest <em>M. sedimenti</em> via “untargeted grazing” in seeps. Further studies must examine the exact relationship between diet and δ<sup>13</sup>C in foraminiferal test on several different paleo-oceanographically relevant species.</p>

Grazing of the copepod Cyclops vicinus on toxic Microcystis aeruginosa: potential for controlling cyanobacterial blooms and transfer of toxins

2018 ◽  
Vol 47 (3) ◽  
pp. 296-302 ◽  
Author(s):  
Zakaria A. Mohamed ◽  
Asmaa A. Bakr ◽  
Hamed A. Ghramh
Keyword(s):  
Microcystis Aeruginosa ◽  
Grazing Rate ◽  
Cyanobacterial Blooms ◽  
Feeding Experiments ◽  
Cyclops Vicinus ◽  
Ankistrodesmus Falcatus ◽  
Toxic Cyanobacteria ◽  
Study Laboratory ◽  
Grazer Species

Abstract Grazing of zooplankton on phytoplankton may contribute to a reduction of harmful cyanobacteria in eutrophic waters. However, the feeding capacity and interaction between zooplankton and toxic cyanobacteria vary among grazer species. In this study, laboratory feeding experiments were designed to measure the grazing rate of the copepod Cyclops vicinus on Microcystis aeruginosa and the potential microcystin (MC) accumulation in the grazer. Copepods were fed a mixed diet of the edible green alga Ankistrodesmus falcatus and toxic M. aeruginosa for 10 days. The results showed that C. vicinus efficiently ingested toxic Microcystis cells with high grazing rates, varying during the feeding period (68.9–606.3 Microcystis cells animal-1 d-1) along with Microcystis cell density. Microcystis cells exhibited a remarkable induction in MC production under grazing conditions with concentrations 1.67–12.5 times higher than those in control cultures. Furthermore, C. vicinus was found to accumulate MCs in its body with concentrations increasing during the experiment (0.05–3.21 μg MC animal-1). Further in situ studies are needed to investigate the ability of Cyclops and other copepods to assimilate and detoxify MCs at environmentally relevant concentrations before deciding on the biocontrol of Microcystis blooms by copepods.

Crustacean Plankton Communities in Forty-Five Lakes in the Experimental Lakes Area, Northwestern Ontario

1971 ◽  
Vol 28 (2) ◽  
pp. 231-244 ◽  
Author(s):  
Kazimierz Patalas
Keyword(s):  
Common Species ◽  
Medium Size ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Lake Morphology ◽  
Diaptomus Oregonensis ◽  
Crustacean Plankton ◽  
Limnocalanus Macrurus ◽  
Zooplankton Communities ◽  
Plankton Communities

Zooplankton communities were characterized on the basis of samples taken in summer as vertical net hauls in the central part of lakes. Twenty-eight species of crustaceans were found in the 45 lakes studied. The highest number of species as well as the highest numbers of individuals (per unit of area) usually occurred in the largest deepest lakes with most transparent water.The most common species were: Bosmina longirostris, Tropocyclops prasinus mexicanus, Mesocyclops edax, Diaptomus minutus, Holopedium gibberum, and Cyclops bicuspidatus thomasi. Daphnids were rather scarcely represented.Senecella calanoides, Limnocalanus macrurus, and Diaptomus sicilis were confined to rather deeper lakes, whereas Diaptomus oregonensis was found mostly in smaller shallower lakes and Diaptomus leptopus in very small, but relatively deep lakes. Diaptomus minutus and C. b. thomasi, though widely distributed, showed a preference for deeper lakes, whereas T. p. mexicanus tended towards smaller shallower lakes.In particular lakes, the number of dominants ranged between 1 and 5, but three dominants per lake was the most commonly encountered case. The simplest community was composed of one cyclopoid, though the most common consisted of one cyclopoid, one diaptomid, and one cladoceran.Four types of communities were distinguished, each of them characteristic for a group of lakes of specific size and depth: (I) in the largest and deepest lakes (389–1007 ha of area, 30–117 m maximum depth); (II) in lakes of medium size and depth (6.5–200 ha, 4.8–33 m); (III) in small and very shallow lakes (3.1–28 ha, 2.7–7.3 m); (IV) in very small lakes with medium depth (1.3–3.7 ha, 6.1–12.8 m).The high degree of similarity between the plankton communities of the Experimental Lakes Area (ELA) and southern Ontario, as well as of some Great Lakes, suggest that they all basically belong to the same zoogeographical area.The fact that most species were distributed evenly throughout ELA may indicate the relative uniformity of the area. In ELA, lake morphology is mainly responsible for defining the type of community.

Hyperbenthic and pelagic predators regulate alternate key planktonic copepods in shallow temperate estuaries

2014 ◽  
Vol 65 (9) ◽  
pp. 791 ◽  
Author(s):  
R. J. Wasserman ◽  
T. J. F. Vink ◽  
R. Kramer ◽  
P. W. Froneman
Keyword(s):  
Population Regulation ◽  
Zooplankton Community ◽  
Copepod Species ◽  
Benthic Fish ◽  
Predator Diversity ◽  
Predatory Impact ◽  
Experimental Treatments ◽  
Zooplankton Communities ◽  
Predatory Pressure

Although predation has been identified as an important community driver, the role of predator diversity in structuring estuarine zooplankton has not been assessed. As such, we investigated the effects of two different zooplanktivorous fish species on the estuarine zooplankton community during a 12-day mesocosm study. Three experimental treatments were established, whereby natural zooplankton communities were subject to either (1) no predatory pressure, (2) predation by a pelagic predator (Monodactylus falciformis) or (3) predation by a hyper-benthic predator (Glossogobius callidus). The pelagic feeding M. falciformis fed largely on the numerically dominant mid-water copepod species, Paracartia longipatella. In contrast, the hyper-benthic fish had a greater predatory impact on the less numerically dominant copepod, Pseudodiaptomus hessei, which demonstrates strong diel vertical migration. Variations in prey-population regulation are ascribed to the distinct behavioural differences of the predators, and mediated by the differences in behaviour of the copepod species.

Perturbations in Zooplankton Communities in a Continuously Flowing Impoundment System Incubated in situ

1987 ◽  
Vol 44 (S1) ◽  
pp. s154-s162 ◽  
Author(s):  
M. H. Holoka ◽  
S. G. Lawrence
Keyword(s):  
Lake Water ◽  
Zooplankton Community ◽  
Zooplankton Species ◽  
Natural Conditions ◽  
Toxic Materials ◽  
Similarity Indices ◽  
Self Powered ◽  
Percent Similarity ◽  
Zooplankton Communities

An apparatus which draws lake water, either filtered or unaltered, at a preestablished rate through four 40.75 L vessels incubated in situ is described. The system provides facilities for the synchronous addition of experimental liquids such as toxicants. All components are readily transportable. The system is self-powered for periods up to one month depending on the rate of flow chosen. This apparatus provides for the isolation of the zooplankton community from other compartments in the lake, incubation in natural conditions, experimental periods of from 1 to 30 d, maintenance of chosen concentrations of added materials continuously or non-continuously as appropriate, and entry of food organisms with concomitant dilution of wastes and metabolites.The responses of selected zooplankton species or of zooplankton communities to impoundment, manipulation of predator or prey organisms and the addition of nutrient or toxic materials can be assessed as they occur in the naturally varying conditions of a lake environment while the population is being held as a separate and defined part of the whole-lake ecosystem.Methods for the construction and use of the apparatus, and for collection of samples are described. Methods for enumerating organisms in several sizes of subsamples are assessed. Data generated in several experiments are analyzed using standard statistical methods and percent similarity indices.

The Relict Fauna of Greiner Lake, Victoria Island, N.W.T., Canada

1962 ◽  
Vol 19 (6) ◽  
pp. 1105-1120 ◽  
Author(s):  
Lionel Johnson
Keyword(s):  
North America ◽  
Sea Level ◽  
Lake Water ◽  
New Record ◽  
Lake Victoria ◽  
Summer Temperature ◽  
Mysis Relicta ◽  
Limnocalanus Macrurus ◽  
Victoria Island ◽  
Saduria Entomon

A survey of Greiner Lake in Victoria Island revealed the presence there of four species usually considered to be 'relicts' of marine or glacial events. The species are: Mysis relicta, Limnocalanus macrurus, Gammaracanthus loricatus aestuariorum and Mesidothea (Saduria) entomon. M. entomon is a new record for fresh waters isolated from contact with the sea in North America and G. loricatus aestuariorum is a new record for this region. Greiner Lake (15 m above sea level) is in an area that has risen from the sea within the last 1,300 years. It has a maximum depth of 11 m and a maximum summer temperature of approximately 8 °C. An analysis of the lake water is given and also a brief account of other species present. Possible methods for the arrival of the relicts in Victoria Island are discussed.

scholarly journals Diets and Seasonal Ingestion Rates of Aurelia coerulea (Cnidaria: Scyphozoa) Polyps by in situ Feeding Experiments in Jiaozhou Bay, China

2021 ◽  
Vol 8 ◽  
Author(s):  
Wang Pengpeng ◽  
Zhang Fang ◽  
Guo Dongjie ◽  
Sun Song
Keyword(s):  
Prey Capture ◽  
Prey Availability ◽  
Ingestion Rate ◽  
Jiaozhou Bay ◽  
Gut Contents ◽  
Natural Diet ◽  
Ingestion Rates ◽  
Aurelia Coerulea ◽  
Feeding Experiments

The benthic scyphopolyp population is an important stage in the scyphozoan lifecycle. Nevertheless, few studies have detailed the natural feeding and quantified the energy flux of polyps based on field research. To better understand the scyphopolyp natural diet and seasonal variation patterns in the ingestion rate, in situ feeding experiments were conducted on Aurelia coerulea polyps in Jiaozhou Bay, China from August 2018 to April 2019. The diet of A. coerulea polyps was determined by gut content analysis. Digestion rates were also measured. Ingestion rates, based on the gut contents and digestion rates, were assessed monthly. Copepods, copepod nauplii, and ciliates were identified in the guts of A. coerulea polyps. Copepods with the bulk of total prey intake in number are an important source of nutrition for A. coerulea polyps in Jiaozhou Bay. Prey capture of A. coerulea polyps (prey polyp–1) varied among months, and was highly dependent upon the abundance of planktonic prey in the habitat. Copepods and copepod nauplii were digested more rapidly as temperature increased. Carbon weight-specific ingestion rate exhibited an obvious seasonal change, with the mean value of 0.13 ± 0.12 μg C μg C–1 d–1. More rapid digestion of prey at higher temperatures and larger prey availability would cause a higher ingestion rate in polyps. Scyphopolyps are widely distributed predators in littoral ecosystems and they may play an important role in plankton–benthos coupling by transferring energy from the water column to the benthos. Massive scyphopolyps blooms may influence pelagic ecosystems.

scholarly journals Overcoming Deterrent Metabolites by Gaining Essential Nutrients: A Lichen/Snail Case Study

2019 ◽  
Author(s):  
Alice Gadea ◽  
Maryvonne Charrier ◽  
Mathieu Fanuel ◽  
Philippe Clerc ◽  
Corentin Daugan ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Usnic Acid ◽  
Feeding Preferences ◽  
Feeding Experiments ◽  
Feeding Choice ◽  
Lichen Thallus ◽  
Choice Feeding

Lichen secondary metabolites are generally considered as repellent compounds for lichen feeders. Nevertheless, if the only food available consists in lichens rich in secondary metabolites, lichenophages such as Notodiscus hookeri, a gastropod native from the Possession Island, seem able to implement strategies to overcome the toxicity of these metabolites. Thus, the balance between phagostimulant nutrients and deterrent metabolites appears to play a key role in their feeding preferences. To further understand lichen-gastropod interactions, we studied the feeding behavior of Notodiscus hookeri fed exclusively with Usnea taylori, a lichen rich in usnic acid and arabitol. Snail feeding choice experiments with intact lichens vs acetone-rinsed lichens were carried out to study the influence of secondary metabolites. Simultaneously, usnic acid and arabitol were quantified and localized within the lichen thallus using HPLC-DAD-MS and in situ imaging by mass spectrometry to assess whether their spatial distribution induce preferential snail grazing. Then, no-choice feeding experiments were devised using usnic acid and arabitol embedded in artificial diet, separately or together.  This case study demonstrated that the nutritional activity of N. hookerii was governed by the chemical quality of the food and primarily by nutrient availability (arabitol), despite the presence of deterrent metabolites (usnic acid).

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