THE EFFECT OF PREY DENSITY ON PREY CONSUMPTION AND OVIPOSITION IN ADULTS OF TYPHLODROMUS (T.) OCCIDENTALIS NESBITT (ACARINA: PHYTOSEIIDAE) IN THE LABORATORY

1961 ◽  
Vol 39 (3) ◽  
pp. 311-315 ◽  
Author(s):  
D. A. Chant
Keyword(s):  
Prey Density ◽  
Laboratory Experiments ◽  
Prey Species ◽  
Prey Consumption ◽  
Consumption Rates

Laboratory experiments indicated that the oviposition and prey consumption rates of Typhlodromus (T.) occidentalis Nesbitt depend on the number of prey available to the predator. The prey species used was Tetranychus telarius (L.).

Activity Differences influencing Food Selection in the Marine Fish Pomatoschistus microps

1986 ◽  
Vol 43 (1) ◽  
pp. 223-227 ◽  
Author(s):  
Carin Magnhagen
Keyword(s):  
Prey Density ◽  
Laboratory Experiments ◽  
Prey Species ◽  
Food Selection ◽  
Reproductive Period ◽  
Food Selectivity ◽  
Encounter Rate ◽  
Low Density ◽  
Low Activity ◽  
Prey Items

Diets of female and male Pomatoschistus microps during the reproductive period (May–July) differed. Males ate less but used a wider range of prey species than did females. While males guard the eggs and therefore are tied to a nest during the breeding season, females have a higher mobility which leads to a higher prey encounter rate and hence a higher food selectivity than in males. After reproduction the differences between the sexes in food intake and diet disappeared. In laboratory experiments the fish were less active in aquaria with a high prey density than in those with a low density. A decrease in food selectivity with an increasing prey density can thus be due to a decrease in the activity of the fish. At a high prey density, P. microps may benefit from having a low activity and taking unselectively the prey items in its vicinity. The advantages could be reduced detectability by predators and decreased energy expenditure due to locomotion.

The influence of prey density and fish size on prey consumption in common sole (Solea solea L.)

2018 ◽  
Vol 31 ◽  
pp. 16 ◽  
Author(s):  
Stephan Siegfried Werner Ende ◽  
Rajko Thiele ◽  
Johan W. Schrama ◽  
Johan A.J. Verreth
Keyword(s):  
Prey Density ◽  
Prey Consumption ◽  
Fish Size ◽  
Positive Correlation ◽  
Nereis Virens ◽  
Solea Solea ◽  
Consumption Rates ◽  
The Relationship ◽  
Common Sole

We examined the influence of prey density and fish size on prey consumption in common sole (Solea solea L.) foraging on buried ragworm Alitta virens (Sars) (formerly known as Nereis virens (Sars)). The tested prey densities of 0.8, 2.2, 4.3 and 6.5 individuals dm−2 were exposed to common soles of either 100 g or 300 g. At each prey density common sole foraged for 48 h. At both common sole classes studied, a positive correlation between prey consumption and prey density was observed (P < 0.001). Relationships however differed between 100 and 300 g common sole. In 300 g common sole the relationship between prey consumption and prey density was linear (P < 0.001), whereas in 100 g common sole the relationship between prey density and prey eaten was polynomial (P = 0.018). Small common sole reached satiety prey consumption rates at nearly every prey density while large common sole did not reach satiation rates even at highest prey densities. The data suggest that in nature, polychaetes such as A. virens may contribute to the diet of small common sole even when they are only moderately abundant. In contrast, polychaetes may not be an ideal prey for larger common sole as indicated by the absence of satiety regardless of prey density.

scholarly journals The exotic gastropod Clea helena (von dem Busch, 1847) as a predator of freshwater gastropods: a threat to native biota in India?

2021 ◽  
Vol 21 (1) ◽  
pp. 55-62
Author(s):  
Pranesh Paul ◽  
Koushik Paul ◽  
Rupsha Karmakar ◽  
Arnab Shee ◽  
Debaditya Kumar ◽  
...  
Keyword(s):  
Prey Density ◽  
Prey Species ◽  
Prey Size ◽  
Freshwater Ecosystems ◽  
Size Class ◽  
Prey Consumption ◽  
Freshwater Snails ◽  
Snail Species ◽  
Species Identity ◽  
Freshwater Gastropods

Abstract The carnivorous snail Clea (Anentome) helena (von dem Busch, 1847) (Gastropoda: Nassariidae), commonly called as the “assassin snail” is sold worldwide including India for aesthetics and the ability to kill pest snails in aquaria. Assuming invasion as a fair possibility, the predation potential of C. helena on seven native freshwater snails was assessed. The exotic predator consumed all the native snail species provided in the experiment and prey consumption varied with the prey species identity, the prey density and the prey size class. Future colonization and establishment of C. helena in Indian freshwater ecosystems may reduce the abundance of the native gastropod snails, in absence of suitable intervention.

Planktivory by alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) on microcrustacean zooplankton and dreissenid (Bivalvia: Dreissenidae) veligers in southern Lake Ontario

1995 ◽  
Vol 52 (5) ◽  
pp. 925-935 ◽  
Author(s):  
Edward L. Mills ◽  
Connie Adams ◽  
Robert O'Gorman ◽  
Randall W. Owens ◽  
Edward F. Roseman
Keyword(s):  
Laboratory Experiments ◽  
Lake Ontario ◽  
Osmerus Mordax ◽  
Field Observations ◽  
Alosa Pseudoharengus ◽  
Rainbow Smelt ◽  
Consumption Rates ◽  
South Shore ◽  
Young Of The Year ◽  
Veliger Larvae

The objective of this study was to describe the diet of young-of-the-year and adult alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) in nearshore waters coincident with the colonization of Lake Ontario by Dreissena. Laboratory experiments and field observations indicated that alewife and rainbow smelt consumed dreissenid veligers and that the veligers remained intact and identifiable in the digestive tract for several hours. Dreissenid larvae were found in field-caught alewife and rainbow smelt in August 1992, even though veliger densities were low (<0.1/L). Zooplankton dominated the diet of all fish and veliger larvae were <0.1% of the biomass of prey eaten by these fish. Density of veligers and the distribution of settled dreissenids declined from west to east along the south shore of Lake Ontario. Based on veliger consumption rates we measured and the abundance of veligers and planktivores, we conclude that planktivory by alewife and smelt in the nearshore waters of Lake Ontario did not substantially reduce the number of veligers during 1991–1993. However, our results indicate that if the density of veligers in Lake Ontario decreases, and if planktivores remain abundant, planktivory on veliger populations could be significant.

Prey consumption rates and compatibility with pesticides of four predatory mites from the family Phytoseiidae attacking Thrips palmi Karny (Thysanoptera: Thripidae)

2012 ◽  
Vol 68 (9) ◽  
pp. 1289-1295 ◽  
Author(s):  
Andrew GS Cuthbertson ◽  
James J Mathers ◽  
Pat Croft ◽  
Nicola Nattriss ◽  
Lisa F Blackburn ◽  
...  
Keyword(s):  
Predatory Mites ◽  
Prey Consumption ◽  
Thrips Palmi ◽  
The Family ◽  
Consumption Rates

scholarly journals Disentangling the effects of predator body size and prey density on prey consumption in a lizard

2010 ◽  
Vol 25 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Manuela González‐Suárez ◽  
Marianne Mugabo ◽  
Beatriz Decencière ◽  
Samuel Perret ◽  
David Claessen ◽  
...  
Keyword(s):  
Body Size ◽  
Prey Density ◽  
Prey Consumption

Prey Consumption and Oviposition of the Aphidophagous PredatorMenochilus sexmaculatus(Coleoptera: Coccinellidae) in Relation to Prey Density and Adult Size

2001 ◽  
Vol 30 (6) ◽  
pp. 1182-1187 ◽  
Author(s):  
Basant K. Agarwala ◽  
Pranbjit Bardhanroy ◽  
Hironori Yasuda ◽  
Tadashi Takizawa
Keyword(s):  
Prey Density ◽  
Prey Consumption ◽  
Adult Size

Differences in feeding selectivity and efficiency between young-of-the-year European perch (Perca fluviatilis) and roach (Rutilus rutilus) — field observations and laboratory experiments on the importance of prey movement apparency vs. evasiveness

Biologia ◽  
2009 ◽  
Vol 64 (4) ◽  
Author(s):  
Jiří Peterka ◽  
Josef Matěna
Keyword(s):  
Fish Species ◽  
Prey Density ◽  
Laboratory Experiments ◽  
Feeding Time ◽  
Feeding Experiment ◽  
Feeding Selectivity ◽  
European Perch ◽  
Feeding Efficiency ◽  
Young Of The Year ◽  
Field And Laboratory Conditions

AbstractFeeding selectivity and efficiency of young-of-the-year European perch and roach were compared under field and laboratory conditions. In laboratory experiments, the importance of prey evasiveness versus prey movement conspicuousness for fish selectivity was evaluated with respect to changing Cladocera/Copepoda prey ratio. Feeding efficiency was additionally investigated in relation to feeding time (5, 10, 20 min) and prey density (approx. 50, 200, 700 ind. L−1). In Říov Reservoir, the diet of both fish species was nearly exclusively composed of crustacean zooplankton. In roach, diet shifted from rotifers and bosminids in May, towards Daphnia sp. and Leptodora kindtii in June and July. Daphnia contributed almost exclusively to the roach diet since June, composing on average more than 94% of total prey. Cyclopoid copepods, occurred in the roach’s diet only on the first sampling date; later on both cyclopoid and calanoid copepods were completely absent. On the other hand, copepods played an important role in the diet of perch. In early and mid-June when their share in the zooplankton was particularly high, copepods contributed by more than 50% to the diet of perch. Although their contribution dropped with their decline in zooplankton in June/July, by the end of July they again comprised about one third of perch’s diet. In both fish species, the increase in numbers of cladocerans in their diet was related to increase in SL. In roach, the numbers of consumed prey were doubled every twenty days during the investigated period. In perch the increase was not so consistent, but significantly higher efficiency of perch was reported on three out of six sampling dates. In laboratory experiments, roach showed a distinct avoidance for copepods and a preference for cladocerans. Both prey categories were only fed non-selectively when they dominated the prey mixture. Perch selectivity was more diversified. Contrary to roach, perch were fed copepods non-selectively on a balanced prey ratio. Further, with an increasing share of Cladocera, a situation resembling that of roach and Copepoda was avoided. However, when the share of copepods in the prey mixture dropped below ten percent, they were consumed non-selectively and with their ongoing decline in the prey mixture their preference even increased. Feeding efficiency differed significantly between perch and roach when foraging on copepods exclusively or on a prey mixture where copepods predominated. In the short time feeding experiment (5 min) with copepods, perch consumed on average 5.9 times more prey than roach. Although roach increased their success with increasing time it was still 1.7 times greater than for perch in the long time feeding experiment (20 min). Total numbers of prey consumed were positively affected by prey density and feeding time. With increasing feeding time, the consumption rate generally declined. With a fourfold increase in feeding time, the numbers of consumed prey increased on average only two times. Only in roach feeding on copepods did the numbers of prey consumed per minute of feeding increase with increasing feeding time. However, the overall numbers were low. Differences in feeding selectivity and efficiency between perch and roach juveniles were found to be significant both in the field and laboratory experiments. In roach, selectivity was determined solely by prey evasiveness. By contrast, perch’s selectivity was influenced by prey movement conspicuousness; prey escape abilities did not play an important role. Perch were more efficient foragers on evasive prey, but its feeding efficiency for non-evasive prey was not lower than that of roach. According to our observations, we suggest feeding behaviour to be responsible for the roach’s inefficiency in capturing evasive copepods.

All's good in a famine? Hydrobia ulvae as a secondary prey for juveniles of Iceland moonsnails Amauropsis islandica at the White Sea sandflats

2015 ◽  
Vol 95 (8) ◽  
pp. 1601-1606 ◽  
Author(s):  
Dmitriy Aristov ◽  
Marina Varfolomeeva ◽  
Georgii Puzachenko
Keyword(s):  
Consumption Rate ◽  
Prey Species ◽  
White Sea ◽  
Sediment Cores ◽  
Macoma Balthica ◽  
The White Sea ◽  
Floor Effect ◽  
Dietary Shift ◽  
Hydrobia Ulvae ◽  
Consumption Rates

Many size-selective predators switch their diet during ontogeny. At the White Sea, the adult moonsnails Amauropsis islandica feed mostly on Macoma balthica clams. The diet of juveniles was largely unknown. We conducted a field survey and a caging experiment to find out if juvenile moonsnails can prey on Hydrobia ulvae, and whether they prefer this snail to their usual prey. Live molluscs and their intact or perforated shells were collected from 34 sediment cores. We exposed the single-prey cages with 50 Macoma (MP) or 50 Hydrobia (HP) together with five Amauropsis juveniles, as well as the cages where both prey species were in a 25:25 proportion (HMP). While live Hydrobia was more abundant in the natural assemblages, Amauropsis preferred Macoma, as indicated by proportions of perforated shells. The caging experiment produced similar results. Per capita Macoma consumption rate was significantly higher than Hydrobia consumption rate (6.4 ± 0.5 mg day−1 ind.−1vs. 1.4±0.2 mg day−1 ind.−1 in MP and HP respectively). Prey consumption rates in the single-prey treatments were higher than in mixed-prey cages regardless of prey species. Different mechanisms explain this variation: for Hydrobia it is a consequence of the dietary shift, while for Macoma it reflects the ‘floor’ effect in HMP cages, where virtually all Macoma had been drilled by the end of exposure term. While Macoma is the preferable prey of young Amauropsis, Hydrobia can supplement the diet of juveniles when Macoma is scarce in certain locations.

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