Change search
ReferencesLink to record
Permanent link

Direct link
Predator-prey interactions in a variable environment: responses of a caddis larva and its blackfly prey to variations in stream flow
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
2009 (English)In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 46, no 3, 193-204 p.Article in journal (Other academic) PublishedText
Abstract [en]

Predator-prey studies in streams have traditionally focused on mayfly-stonefly interactions in relatively constant flow conditions. In reality, however, lotic prey encounter multiple types of predators, most of which are restricted to low-velocity microhabitats. By contrast, some invertebrate prey may occur in very high current velocities. For example, many blackfly species are able to feed at velocities of 100 cm s(-1), whereas even moderate currents reduce the hunting efficiency of their invertebrate predators. The caddisfly larvae of the genus Rhyacophila, however, may be an exception to the pattern of reducing predator efficiency with increasing velocity. Using a combination of laboratory and field experiments and behavioral field observations, we examined the interaction between predatory Rhyacophila caddis larvae and larval blackflies along a velocity gradient of 20-120 cm s(-1). In laboratory experiments, Rhyacophila preferred currents slower than 50 cm s(-1) while blackflies exhibited a wide tolerance of currents and frequently occurred in currents exceeding 100 cm s(-1). In direct field observations, total activity and distance moved by Rhyacophila were similar at all current velocity regimes tested, but frequency of predation attempts on blackflies was lowest at the highest velocities (> 100 cm s(-1)). In a field colonization study, blackflies avoided substrates with the slowest velocities (< 40 cm s(-1)), as also did the caddis larvae. Only velocities approaching 100 cm s(-1) provide blackflies with refuge from predation by Rhyacophila. Being able to maneuver across a wide range of velocities, Rhyacophila may have more pervasive effects on their prey than other lotic invertebrate predators.

Place, publisher, year, edition, pages
Finnish Zoological and Botanical Publishing Board , 2009. Vol. 46, no 3, 193-204 p.
Keyword [en]
current velocity, diptera-simuliidae, feeding insect, fly larvae, field-test, disturbance, stoneflies, preference, habitat, invertebrates
National Category
Environmental Sciences Ecology Zoology
URN: urn:nbn:se:umu:diva-115993ISI: 000269330600004OAI: diva2:906904
Available from: 2016-02-25 Created: 2016-02-08 Last updated: 2016-02-25Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Malmqvist, Björn
By organisation
Department of Ecology and Environmental Sciences
In the same journal
Annales Zoologici Fennici
Environmental SciencesEcologyZoology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 24 hits
ReferencesLink to record
Permanent link

Direct link