Tollrian, R; Laforsch, C: Linking predator kairomones and turbulence: synergistic effects and ultimate reasons for phenotypic plasticity in Daphnia cucullata, Archiv für Hydrobiologie, 167(1-4), 135-146 (2006), doi:10.1127/0003-9136/2006/0167-0135
Key words: cyclomorphosis, random flow, inducible defence, helmet, synergistic effects
Abstract:
The seasonal change in helmet size in Daphnia cucullata has been studied for over one century. Recently it has been shown that helmets in D. cucullata, which have been found to reduce predator caused mortality, can be induced by chemical cues released by several predatory invertebrates. However, it also has been shown that tur- bulence induces this trait. The relation and interplay of both inducing cues is not known. Here we present results from lab experiments showing that predator cues and turbulence can act synergistically. Both factors in combination induced significantly larger responses, compared to each factor alone, and helmets reached the maximum sizes found in natural lakes. This result might help to explain the observation of large helmets in this species in nature. The ultimate reason behind the turbulence induction is yet unknown.We link both induction factors to predation, as the ultimate reason, by testing the hypothesis that D. cucullata can respond to turbulence produced by swimming invertebrates.We found that helmet growth increased significantly in direct contact to both the heterospecific Daphnia magna and the predator Cyclops sp. Treat- ments which accounted for chemical cues alone did not increase helmet growth in re- sponse to cues from D. magna,or Cyclops under these conditions. Together, these re- sults indicate that D. cucullata is able to respond to mechanical cues produced by swimming invertebrates. Thus, our study suggests that both chemical cues and turbu- lence generated by predatory invertebrates might act synergistically to induce helmets as effective protection against invertebrate predation.
Upcoming ...


BayCEER Colloquium:
Th. 2020-12-03
An engineered (water) future?
Th. 2020-12-10
Investigating communal pathogen defense and its role in social evolution
Ecological-Botanical Garden:
Th. 2020-12-03
Entfällt: Ökumenische Andacht zum Advent mit dem Swahili Chor Bayreuth (KHG & ESG)
Su. 2020-12-06
Entfällt: Führung nach Anmeldung: Zimt & Mandelkern: Pflanzen in der Weihnachtsbäckerei
Geographisches Kolloquium:
Tu. 2020-12-08
People, pathogens, places: where medical geography meets disease ecology?
BayCEER Blog
13.01.2020
Why Science Communication?
24.05.2019
Stoichiometric controls of C and N cycling
07.05.2019
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
16.04.2019
Picky carnivorous plants?
RSS Blog as RSS Feed
Weather research site
Luftdruck (356m): 981.1 hPa
Lufttemperatur: 0.9 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 17m): 4.5 km/h
Wind (Max.): 10.8 km/h
Windrichtung: O

...more
Globalstrahlung: -1 W/m²
Lufttemperatur: -1.9 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 32m): 0.0 km/h

...more
This site makes use of cookies More information