A1 Refereed original research article in a scientific journal
SPECIFICITY OF PREDATOR-INDUCED NECK SPINE AND ALTERATION IN LIFE-HISTORY TRAITS IN DAPHNIA-PULEX
Authors: REPKA S, KETOLA M, WALLS M
Publisher: KLUWER ACADEMIC PUBL
Publication year: 1994
Journal:: Hydrobiologia
Journal name in source: HYDROBIOLOGIA
Journal acronym: HYDROBIOLOGIA
Volume: 294
Issue: 2
First page : 129
Last page: 140
Number of pages: 12
ISSN: 0018-8158
DOI: https://doi.org/10.1007/BF00016853
Abstract
It has been proposed that the predator-induced defensive neck spine in Daphnia pulex has a demographic cost. Our results show that this cost is not merely an allocation cost related formation and maintenance of the neck spine. In a life table experiment, we tested whether spine induction life history traits in D. pulex are affected by different invertebrate predators: first and third instar Chaoborus, fourth instar Mochlonyx and two size classes of Notonecta and Dytiscus larvae. D. pulex showed sensitivity to the different predators. Predator-exposure affected one or more of the following life history traits of D. pulex: the timing of first reproduction, clutch size, and growth. In some cases, exposure to predators altered life history traits when neck spine induction did not occur. These shifts in life history traits occurring in the absence of spine induction may be caused by behavioral or physiological changes triggered by the predators.
It has been proposed that the predator-induced defensive neck spine in Daphnia pulex has a demographic cost. Our results show that this cost is not merely an allocation cost related formation and maintenance of the neck spine. In a life table experiment, we tested whether spine induction life history traits in D. pulex are affected by different invertebrate predators: first and third instar Chaoborus, fourth instar Mochlonyx and two size classes of Notonecta and Dytiscus larvae. D. pulex showed sensitivity to the different predators. Predator-exposure affected one or more of the following life history traits of D. pulex: the timing of first reproduction, clutch size, and growth. In some cases, exposure to predators altered life history traits when neck spine induction did not occur. These shifts in life history traits occurring in the absence of spine induction may be caused by behavioral or physiological changes triggered by the predators.