EurekaMag.com logo
+ Site Statistics
References:
48,253,228
Abstracts:
22,798,842
+ Resolve Accession
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
Submit PDF Full TextSubmit PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Invertebrate predation on patchy and mobile prey in streams


, : Invertebrate predation on patchy and mobile prey in streams. Journal of Animal Ecology 60(2): 625-642

A series of field experiments with predatory net-spinning larvae of the caddisfly Plectrocnemia conspersa (Curtis) were carried out in a small fishless stream to determine any impact of this predator on the abundance of its prey. Densities of fifth instar caddisfly larvae were manipulated in enclosures permeable to most other invertebrates in the stream. Three experiments were carried out (spring, summer and winter), each with a 2-week preliminary colonization period to establish prey assemblages inside enclosures. Then zero, one or four predators were introduced per cage (low, ambient or high predator densities). Significant predator impacts were observed in winter only, and results varied with prey taxon. These observations could be attributed either to largely trivial effects of predation, or to technical difficulties in its detection. Two subsequent experiments (A and B) were designed to assess how the detection of predator impact in enclosures is influenced by the patchy microdistribution of lotic invertebrates, and by the continuous exchange of mobile prey with the benthos. In experiment A, prey exchange rates were manipulated by wrapping some cages with fine mesh after the initial colonization period. The evidence that exchange rate influenced the detection of impact by predators was equivocal and may have been obscured by the natural, spatial variability of lotic invertebrates. In experiment B, exchange rates were again altered by manipulating the mesh size of enclosures but, in addition, initial variability in the number of prey per cage was reduced by stocking rather than by allowing colonization. The abundance of total prey and of individual prey groups was reduced significantly in predator treatments compared with controls. Predator impacts were most pronounced at low exchange rates, and were less distinct at high exchange. The effects of mesh size on prey exchange varied among taxa in relation to species-specific morphology and dispersal behaviour. The experimental detection of predator impacts therefore appears to be highly dependent on both prey mobility and spatial heterogeneity. A graphical model is presented to illustrate how the detection of predation effects inside enclosures may be influenced by prey mobility. The continuous redistribution of prey populations may be an important factor to include in models of community structure and organization in heterogeneous environments with mobile species, such as streams.

Order PDF Full Text

Close
Close

Click here to order any other PDF Full Text


Accession: 002416670

DOI: 10.2307/5302

Download PDF Full Text: Invertebrate predation on patchy and mobile prey in streams


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Other references

Kushnip, I.I.; Zaretskaia, T.A.; Zurab'ian, C.G.; Mitina, T.G., 1973: Qualitative characteristics of filling of root canals. Stomatologiia 52(4): 13-16

Yuan, F..; Liu, S.., 2002: A new subspecies of Neptis ilos Fruhstorfer from China Lepidoptera Nymphalidae. Memoirs of Beijing Natural History Museum, 59: 5-11

Kuznetsova V.K.; Lyubimov G.A., 1987: On the concept of equal pressure point and its applications. An experimental verification of the equal pressure point theory, concerning alveolar and pleural pressure and airway resistance, was carried out. It is possible to use the equal pressure point theory in the diagnosis of human respiratory diseases...

Su, W.C.iung; Fang, J.M.n; Cheng, Y.S.ia, 1994: Labdanes from Cryptomeria japonica. Twenty-seven labdanes were isolated from the leaves of Cryptomeria japonica. The new compounds include 15-(2-oxopropylidene)labd-8(17)-en-19-oic acid, 15-oxolabda-8(17),13E-dien-19-oic acid, 7-beta-acetoxy-15-hydroxylabda-8(17),13E-dien-19-oic aci...

Swany, M.R.; Scott, R.D., 1993: Posterior polyethylene wear in posterior cruciate ligament-retaining total knee arthroplasty. A case study. Controversy over whether to retain the posterior cruciate ligament (PCL) during primary total knee arthroplasty continues. Both the retaining and substituting designs have their respective advantages and disadvantages. In order to capitalize on th...

Bandel Klaus, 1972: Paleoecology and paleogeography in the Devonian and lower Carboniferous of the central Carnic Alps. Carbonate sediments, algal and faunal assemblages, sedimentary facies, petrology, diagenesis, bibliography, Austria.

Belge, C.; Hammond, J.; Dubois-Deruy, E.; Manoury, B.; Hamelet, J.; Beauloye, C.; Markl, A.; Pouleur, A-Catherine.; Bertrand, L.; Esfahani, H.; Jnaoui, K.; Götz, K.R.; Nikolaev, V.O.; Vanderper, A.; Herijgers, P.; Lobysheva, I.; Iaccarino, G.; Hilfiker-Kleiner, D.; Tavernier, Gève.; Langin, D.; Dessy, C.; Balligand, J-Luc., 2014: Enhanced expression of β3-adrenoceptors in cardiac myocytes attenuates neurohormone-induced hypertrophic remodeling through nitric oxide synthase. β1-2-adrenergic receptors (AR) are key regulators of cardiac contractility and remodeling in response to catecholamines. β3-AR expression is enhanced in diseased human myocardium, but its impact on remodeling is unknown. Mice with cardiac myocyt...

Alegria, J.R.; Miller, T.D.; Gibbons, R.J.; Yi, Q-Long.; Yusuf, S., 2007: Infarct size, ejection fraction, and mortality in diabetic patients with acute myocardial infarction treated with thrombolytic therapy. Background Diabetic patients with acute myocardial infarction (MI) have higher mortality than nondiabetic patients. The purpose of this study was to examine if larger infarct size explains the higher mortality in diabetic patients with acute ST-se...

Sergeev, G.V.; Gilep, A.A.; Estabrook, R.W.; Usanov, S.A., 2006: Expression of outer mitochondrial membrane cytochrome b5 in Escherichia coli. purification of the recombinant protein and studies of its interaction with electron-transfer partners. In the present work, we report expression in Escherichia coli, purification, and characterization of recombinant full-length cytochrome b(5) from outer mitochondrial membrane. Optimization of expression conditions for cytochrome b(5) from outer mi...

Jiang, B.; He, Y.; Zuo, F.; Wu, L.; Liu, Q-Hui.; Zhang, L.; Zhou, C-Xi.; Cheng, K.K.; Chan, S.S.C.; Lam, T.Hing., 2016: Effectiveness of varenicline and counselling for smoking cessation in an observational cohort study in China. To evaluate the effectiveness of varenicline for smoking cessation in Chinese smokers in a real world cessation clinic practice. A prospective observational study. Beijing, China. A total of 924 smokers (883 men and 41 women) who attended a smokin...