ISSN:
1432-1939
Keywords:
Predation
;
Inducible defences
;
Phenotypic plasticity
;
Daphnia
;
Neckteeth
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Juvenile Daphnia pulex form neckteeth in reponse to chemicals released by predatory Chaoborus crystallinus larvae. Formation of neckteeth is strongest in the second instar followed by the third instar, whereas only small neckteeth are found in the first and fourth instar of experimental clones. Predation experiments showed that body-size-dependent vulnerability of animals without neckteeth to fourth instar C. crystallinus larvae matched the pattern of neckteeth formation over the four juvenile instars. Predation experiments on D. pulex of the same clone with neckteeth showed that vulnerability to C. crystallinus predation is reduced, and that the induced protection is correlated with the degree of neckteeth formation. The pattern of neckteeth formation in successive instars is probably adaptive, and it can be concluded that neckteeth are formed to different degrees in successive instars as an evolutionary compromise to balance prediation risk and protective costs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00317278
