Experimental evidence of the fundamental feeding niche in Cenocorixa (Hemiptera: Corixidae)

1987 ◽  
Vol 65 (4) ◽  
pp. 967-973 ◽  
Author(s):  
J. D. Reynolds ◽  
G. G. E. Scudder
Keyword(s):  
Laboratory Experiments ◽  
Salinity Range ◽  
Dietary Overlap ◽  
Chironomid Larvae ◽  
Larval Instars ◽  
Food Acceptance ◽  
Low Salinity ◽  
Feeding Niche ◽  
Different Seasons ◽  
Competition For Food

The fundamental feeding niche of Cenocorixa bifida hungerfordi Lansbury and Cenocorixa expleta (Uhler) from saline lakes (500–20 000 μS cm−1 at 25 °C) was determined in laboratory experiments. Each species was offered a variety of potential foods, to determine potential dietary overlap. No significant differences in food acceptance were seen between corixids collected from different lakes or at different seasons. The species were both carnivorous and predaceous, showing little propensity to feed on plant material. Adults of both species attacked and fed on chironomid larvae most frequently; larval instars were less specific. Cenocorixa expleta adults and larval instars of both C. expleta and C. bifida fed more on dead than living food organisms. When offered mixed live Zooplankton, C. bifida chose more Ceriodaphnia than Diaptomus, whereas C. expleta showed no such selection; these differences were not seen with dead Zooplankton. Cenocorixa bifida and C. expleta coexist at moderate salinities, and appear physiologically capable of inhabiting the entire salinity range encountered. Their fundamental feeding niches, although not identical, overlap considerably and could result in competition for food. This could lead to the exclusion of C. expleta from low salinity lakes.

Serological evidence of realized feeding niche in Cenocorixa species (Hemiptera: Corixidae) in sympatry and allopatry

1987 ◽  
Vol 65 (4) ◽  
pp. 974-980 ◽  
Author(s):  
J. D. Reynolds ◽  
G. G. E. Scudder
Keyword(s):  
Saline Lakes ◽  
Habitat Preferences ◽  
Gut Contents ◽  
Serological Analysis ◽  
Serological Evidence ◽  
Low Salinity ◽  
Feeding Niche ◽  
Different Seasons ◽  
Competition For Food

The realized feeding niche of Cenocorixa bifida hungerfordi Lansbury and Cenocorixa expleta (Uhler) from saline lakes (500 – 20 000 μS cm−1 at 25 °C) was determined by serological analysis of gut contents. Antisera prepared from 11 common potential foods were tested on Ouchterlony microplate assemblages against corixid gut contents. No consistent differences were seen between corixids collected from different lakes or at different seasons. Their realized feeding niches are similar but not identical; each instar fed somewhat differently. Diets of the two species when sympatric were markedly different from when they were allopatric. The realized niches appear to be restricted in sympatry, but both species concentrated overall on similar foods, suggesting that food was not limiting. However, the exclusion of C. expleta from low salinity lakes may be a result of competition for food, in addition to habitat preferences and other biotic parameters.

Dietary overlap and food resource partitioning among fish species of a tropical estuary in Northeastern Brazil

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Adna Ferreira da Silva Garcia ◽  
Ana Lúcia Vendel
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Food Resource ◽  
River Estuary ◽  
Niche Overlap ◽  
Northeastern Brazil ◽  
Dietary Overlap ◽  
Feeding Niche ◽  
Tropical Environments ◽  
Food Resource Partitioning

The current work investigates dietary overlap and food partitioning among nine abundant carnivorous fishes caught in the shallow waters of the Paraíba do Norte river estuary, Paraíba State, Brazil. Fishes were sampled with a beach seine net between January and December 2008 and a total of 958 specimens had their stomach content analyzed. Crustacea was the dominant food resource for Lutjanus alexandrei, L. jocu and Bathygobius soporator, whereas Telostei were consumed mainly by Centropomus undecimalis and C. parallelus. In contrast, Polychaeta were preyed upon mainly by Diapterus rhombeus, Eucinostomus argenteus, Sciades herzbergii and S. parkeri. Although most species consumed similar food items, they did that in varying proportions and amounts. Overall, the niche overlap among species was low (< 0.60), but there were several cases where pair of species had their feeding niche highly overlapped (between 0.72 and 0.97). These findings corroborate the hypothesis that food resource partitioning determines species coexistence in estuarine tropical environments.

Factors influencing the distribution of Egregia menziesii (Phaeophyta, Laminariales) in British Columbia, Canada

1978 ◽  
Vol 56 (9) ◽  
pp. 1198-1205 ◽  
Author(s):  
D. K. Gordon ◽  
R. E. DE Wreede
Keyword(s):  
British Columbia ◽  
High Temperature ◽  
Laboratory Experiments ◽  
Algal Flora ◽  
The West ◽  
Common Component ◽  
Strait Of Georgia ◽  
Low Salinity ◽  
Factors Influencing ◽  
Juan De Fuca

Egregia menziesii (Turner) Areschoug is a common component of the algal flora along the west coast of Vancouver Island, Queen Charlotte Strait, and the Strait of Juan de Fuca but is absent from the Strait of Georgia in British Columbia, Canada. This distribution pattern was found to be correlated with temperature and salinity in that E. menziesii is not present in areas where there are seasonal periods of low salinity and high temperature. To test this correlation, field transplants of sporophytes and laboratory experiments with sporophytes and culture work were carried out. The results suggest that the distribution of E. menziesii is limited by specific combinations of salinity and temperature; it requires high salinities and temperatures less than 15 °C for its survival.

Low Salinity Waterflooding at West Salym: Laboratory Experiments and Field Forecasts

2014 ◽  
Author(s):  
B.M.J.M. Suijkerbuijk ◽  
T.G. Sorop ◽  
A.R. Parker ◽  
S.K. Masalmeh ◽  
I.V. Chmuzh ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Low Salinity ◽  
Low Salinity Waterflooding

Factors determining nematode distributions at Cape Hallett and Gondwana station, Antarctica

2013 ◽  
Vol 25 (3) ◽  
pp. 347-357 ◽  
Author(s):  
Mélianie R. Raymond ◽  
David A. Wharton ◽  
Craig J. Marshall
Keyword(s):  
Prey Availability ◽  
Habitat Preferences ◽  
Distribution Patterns ◽  
Organic Content ◽  
Salinity Range ◽  
Strong Impact ◽  
Dry Valleys ◽  
Soil Geochemistry ◽  
Conservation Areas ◽  
Low Salinity

AbstractThe distribution of nematodes at Cape Hallett and Gondwana station was found to be patchy but consistent, broad-scale habitat preferences were identified. These had been previously noted in McMurdo Dry Valleys soils and on Ross Island, indicating that habitat preferences are consistent across large scales and may play a role in determining range limits. Soil geochemistry, especially salinity, has a strong impact on distribution patterns. The distinct distribution patterns of the four species indicate different niches.Panagrolaimus davidiTimm is the only nematode that can survive within penguin rookeries, where salinity is high but bacterial food is plentiful.Scottnema lindsayaeTimm was found across the greatest range of habitats, including the driest sites and largest salinity range.Plectussp. was found in the wettest sites, with high organic content and low salinity.Eudorylaimus antarcticusSteiner (Yeates) was found at low densities and with other nematodes indicating a dependence on prey availability, an example of a biotic interaction structuring even these simplest ecosystems. Field-identifiable features could be used to identify probable nematode habitats, providing useful information for sampling and the selection of conservation areas.

The Super-Cooling Point of the Spiralling Whitefly, Aleurodicus dispersus Russell

2014 ◽  
Vol 1010-1012 ◽  
pp. 1175-1180
Author(s):  
Jun Yu Chen ◽  
Guang Chang Ma ◽  
Yue Guan Fu
Keyword(s):  
Cold Hardiness ◽  
Laboratory Experiments ◽  
Instar Nymph ◽  
Male Adult ◽  
Aleurodicus Dispersus ◽  
Different Seasons ◽  
Egg Stages

Laboratory experiments were conducted to the super-cooling point (SCP) for Aleurodicus dispersus Russell. The results showed that the SCP of A. dispersus was varied in different seasons. The SCP of eggs was-23.21°C in spring, which was lowest than others. The SCP of male adult was-11.10°C in winter, which was highest. For individuals, the lowest SCP was 1th instar nymph, the highest was male adults. The sequence of SCP from low to high is eggs <the 1st instar nymph <2nd instar <3rd instar <4th instar <adults. The SCP of eggs and 1st instar nymph were lowest in every season, which lower than adults significantly (P<0.01). The results revealed stronger cold hardiness in egg stages than adults.

scholarly journals Insignificant enhancement of export flux in the highly productive Subtropical Front, east of New Zealand: a high resolution study of particle export fluxes based on <sup>234</sup>Th:<sup>238</sup>U disequilibria

2011 ◽  
Vol 8 (5) ◽  
pp. 9535-9576
Author(s):  
K. Zhou ◽  
S. D. Nodder ◽  
M. Dai ◽  
J. A. Hall
Keyword(s):  
New Zealand ◽  
Salinity Gradient ◽  
Salinity Range ◽  
Water Type ◽  
Export Flux ◽  
Low Salinity ◽  
Iron Fertilization ◽  
Natural Iron ◽  
Poc Export ◽  
Particle Export

Abstract. We evaluated the downward Particulate Organic Carbon (POC) export fluxes in the Subtropical Frontal zone (STF) of the Southern Ocean. The site is characterized by enhanced primary productivity which has been suggested to be stimulated through so-called natural iron fertilization processes at its northern boundary where iron-depleted subantarctic water (SAW) mixes with oligotrophic, iron-replete subtropical water (STW). We adopted the small-volume 234Th method to achieve highest spatial sampling resolution as possible based on a cruise to the STF to the east New Zealand in austral late autumn-early winter, May–June 2008. The inventories of fluorescence, particulate 234Th and POC observed in the upper 100 m were all elevated in the mid-salinity part of the water type (34.5<S<34.8), compared with low (S<34.5) and high (S>34.8) salinity waters. However, Steady-State 234Th fluxes were similar cross all of the salinity gradient being 1484 in the mid-salinity, and 1761 and 1304 dpm m−2 d−1 in the high and low salinity zones respectively. Bottle POC/Th ratios at the depth of 100 m were used to convert the Th fluxes into POC export flux. The POC flux was again not enhanced in the mid-salinity range where the primary production was highest, being 7.4 mmol C m−2 d−1 as compared to 9.9 mmol C m−2 d−1 in high salinity waters, and 5.9 mmol C m−2 d−1 in low salinity waters. This study implied that natural iron fertilization does not necessarily lead to the enhancement of POC export in STF regions.

scholarly journals Effect of water salinity on survival and osmotic level of larval (Zoea Stage) of mud crabs Scylla tranquebarica

2021 ◽  
Vol 890 (1) ◽  
pp. 012032
Author(s):  
Herlinah ◽  
Sulaeman ◽  
Gunarto ◽  
A Parenrengi ◽  
Rosmiati
Keyword(s):  
Glass Container ◽  
Water Salinity ◽  
Salinity Range ◽  
Asian Countries ◽  
Mud Crab ◽  
Salinity Regime ◽  
Optimal Salinity ◽  
Low Salinity ◽  
Effect Of Water ◽  
Crab Larvae

Abstract Mud crab of the genus Scylla are considered one of the most sought-after seafood today. This crab species has high quality and delicious aging growth rate and encourage expansion in the aquaculture sector especially in Southeast Asian Countries. However, salinity changes will cause changes in organisms osmotic pressure, and every aquatic biota has an optimal salinity range for survival. The study focuses on evaluating the effect of water salinity on the survival and osmotic levels of the purple mud crab, larvae of Scylla tranquebarica at the zoea stage. The LC50 assessment was performed in 10 different level of water salinity (0; 5; 10; 15; 20; 25; 30; 35, 40, and 50 ppt). Each treatment involved 20 ind./L of newly hatched crabs and being observed for 24 h in 10 different water salinity using 1 L volume glass container. The number of crab’s mortality were taken for each salinity regime. Larval behavior monitored during experiment. Meanwhile, the measurement of osmotic level was carried out at the salinity of 25, 30, and 35 ppt. The result shows that mud crab larvae exhibit any tolerance on the low salinity ranged from 0-10 ppt and the salinity of > 40 ppt. On the other hand, mud crab larvae were still able to survive at the salinity ranged from 20-40 ppt for more than 24 hours. The trend of the osmotic level of mud crab to survive is by hypo osmotic to iso osmotic.

Extended Fractional-Flow Model of Low-Salinity Waterflooding Accounting for Dispersion and Effective Salinity Range

SPE Journal ◽  
2019 ◽  
Vol 24 (06) ◽  
pp. 2874-2888 ◽  
Author(s):  
Hasan Al–Ibadi ◽  
Karl D. Stephen ◽  
Eric J. Mackay
Keyword(s):  
Relative Permeability ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Salinity Range ◽  
Fractional Flow ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Low Salinity Waterflooding ◽  
Salinity Water ◽  
The Impact

Summary Low–salinity waterflooding (LSWF) is an emergent technology developed to increase oil recovery. Laboratory–scale testing of this process is common, but modeling at the production scale is less well–reported. Various descriptions of the functional relationship between salinity and relative permeability have been presented in the literature, with respect to the differences in the effective salinity range over which the mechanisms occur. In this paper, we focus on these properties and their impact on fractional flow of LSWF at the reservoir scale. We present numerical observations that characterize flow behavior accounting for dispersion. We analyzed linear and nonlinear functions relating salinity to relative permeability and various effective salinity ranges using a numerical simulator. We analyzed the effect of numerical and physical dispersion of salinity on the velocity of the waterflood fronts as an expansion of fractional–flow theory, which normally assumes shock–like behavior of water and concentration fronts. We observed that dispersion of the salinity profile affects the fractional–flow behavior depending on the effective salinity range. The simulator solution is equal to analytical predictions from fractional–flow analysis when the midpoint of the effective salinity range lies between the formation and injected salinities. However, retardation behavior similar to the effect of adsorption occurs when these midpoint concentrations are not coincidental. This alters the velocities of high– and low–salinity water fronts. We derived an extended form of the fractional–flow analysis to include the impact of salinity dispersion. A new factor quantifies a physical or numerical retardation that occurs. We can now modify the effects that dispersion has on the breakthrough times of high– and low–salinity water fronts during LSWF. This improves predictive ability and also reduces the requirement for full simulation.

Novel Observations of Salinity Transport in Low-Salinity Waterflooding

SPE Journal ◽  
2019 ◽  
Vol 24 (03) ◽  
pp. 1108-1122 ◽  
Author(s):  
Hasan Al-Ibadi ◽  
Karl Stephen ◽  
Eric Mackay
Keyword(s):  
Analytical Solution ◽  
Weighting Function ◽  
Numerical Dispersion ◽  
Salinity Range ◽  
Low Salinity ◽  
Salinity Profile ◽  
Salinity Transport ◽  
Advection Term ◽  
Input Parameters ◽  
Low Salinity Waterflooding

Summary Low-salinity waterflooding (LSWF) is a promising process that could lead to increased oil recovery. To date, the greatest attention has been paid to the complex oil/water/rock chemical reactions that might explain the mechanisms of LSWF, and it is generally accepted that these result in behavior equivalent to changing oil and water mobility. This behavior is modeled using an effective salinity range and weighting function to gradually switch from high- to low-salinity relative permeability curves. There has been limited attention on physical transport of fluids during LSWF, particularly at large scale. We focus on how the salinity profile interacts with water fronts through the effective salinity range and dispersion to alter the transport behavior and change the flow velocities, particularly for the salinity profile. We examined a numerical simulation of LSWF at the reservoir scale. Various representations of the effective salinity range and weighting function were also examined. The dispersion of salinity was compared with a theoretical form of numerical dispersion based on input parameters. We also compared salinity movement with the analytical solution of the conventional dispersion/advection equation. From simulations we observed that salinity is dispersed as analytically predicted, although the advection velocity might be changed. In advection-dominated flow, the salinity profile moves at the speed of the injected water. However, as dispersion increases, the mixing zone falls under the influence of the faster-moving formation water and, thus, speeds up. To predict the salinity profile theoretically, we have modified the advection term of the analytical solution as a function of the formation- and injected-water velocities, Péclet number, and effective salinity range. This important result enables prediction of the salinity transport by this newly derived modification of the analytical solution for 1D flow. We can understand the correction to the flow behavior and quantify it from the model input parameters. At the reservoir scale, we typically simulate flow on coarse grids, which introduces numerical dispersion or must include physical dispersion from underlying heterogeneity. Corrections to the equations can contribute to improving the precision of the coarse-scale models, and, more generally, the suggested form of the correction can also be used to calculate the movement of any solute that transports across an interface between two mobile fluids. We can also better understand the relative behaviors of passive tracers and those that are adsorbed.

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