caa a22 4500 469095989 CHVBK 20180323133031.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF00317464 doi (NATIONALLICENCE)springer-10.1007/BF00317464 Lüning Julia Zoologisches Institut der Universität, Seidlstrasse 25, W-8000, München 2, Federal Republic of Germany aut Phenotypic plasticity of Daphnia pulex in the presence of invertebrate predators: morphological and life history responses [Elektronische Daten] [Julia Lüning] Morphological and life history traits of two clones of the cladoceran Daphnia pulex were measured in the presence and absence of size-selective insect predators, the midge larva Chaoborus flavicans, which preys on small Daphnia, and the water bug Notonecta glauca, which preys on large Daphnia. The aim was to detect predator-induced phenotypic changes, particularly the effect of simultaneous exposure to both types of predators. Other work has shown that in the presence of Chaoborus americanus, Daphnia pulex produce a socalled neck spine which may carry several teeth. The morphological modifications are supposed to serve as an anti-predator device. Furthermore, females exposed to Chaoborus often delay their maturation; this has been interpreted as a cost that balances the benefits of the neck teeth. In this investigation, females of both clones produced fewer but larger offspring than control animals when reared in the presence of Chaoborus flavicans. The offspring showed the typical neck spine and delayed first reproduction. In the presence of Notonecta glauca, one of the clones produced more and smaller offspring, and maturation occurred at earlier instars. The other clone also produced more offspring than the control but there was no size difference. When both predators were present, in most cases the reactions of the daphnids were similar to those in the Notonecta experiment. The response to Chaoborus appeared to be suppressed. The observed modifications are interpreted as evolved strategies that reduce the impact of size-selective predation. They are consistent with predictions of life-history theory. Springer-Verlag, 1992 Daphnia pulex nationallicence Chaoborus nationallicence Notonecta nationallicence Phenotypic plasticity nationallicence Inducible defence nationallicence Oecologia Springer-Verlag 92/3(1992-12-01), 383-390 0029-8549 92:3<383 1992 92 442 https://doi.org/10.1007/BF00317464 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317464 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Lüning Julia Zoologisches Institut der Universität, Seidlstrasse 25, W-8000, München 2, Federal Republic of Germany aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 92/3(1992-12-01), 383-390 0029-8549 92:3<383 1992 92 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer