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THE EVOLUTIONARY ECOLOGY OF AN ANTIPREDATOR REACTION NORM: DAPHNIA PULEX AND CHAOBORUS AMERICANUS
Author(s) -
Parejko Ken,
Dodson Stanley I.
Publication year - 1991
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1991.tb02671.x
Subject(s) - daphnia pulex , biology , predator , predation , cladocera , daphnia , branchiopoda , ecology , pulex , zoology , parthenogenesis , crustacean , genetics , embryo
Ponds containing the parthenogenetic zooplankter Daphnia pulex with and without chaoborid predators were sampled over the course of a season. A significant ( P < 0.05) Spearman rank correlation was found between predator density and the expression of an antipredator defense (neckteeth) by the Daphnia. The reaction norms (percent induction of a single genotype versus predator density) of clones isolated from predator‐free and predator‐rich habitats were determined in a laboratory setting. There was a statistically significant different response among the six clones tested ( P < 0.05). Clones isolated from chaoborid ponds showed significantly greater sensitivity to the presence of predator than clones from predator‐free ponds ( P < 0.05). In the laboratory, food levels under which prey were cultured affected induction of the antipredator response. Highest induction was found at the lowest food level used.