, Volume 231, Issue 2, pp 77–84

Embryology of Chaoborus-induced spines in Daphnia pulex

  • Ken Parejko


Daphnia pulex (Crustacea: Cladocera) embryos were found to be sensitive to a chemical cue (kairomone) in an extract of the predator Chaoborus americanus (Insecta:Diptera). Sensitivity of embryos to the kairomone remains throughout embryonic development. Apparently declining sensitivity as development proceeds may be due to the amount of time the embryos are exposed to the kairomone. Male embryos were also found to be sensitive to the kairomone. The smallest eggs within a brood produced small offspring, which showed the antipredator morphology to a significantly lower degree than largest eggs. The production of the neckteeth is described, at the developmental stage in the maturation of the Daphnia coinciding approximately with the escape of the embryos from the brood chamber.

Key words

Daphnia pulex Chaoborus americanus embryological induction antipredator defense 


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Copyright information

© Kluwer Academic Publishers 1992

Authors and Affiliations

  • Ken Parejko
    • 1
  1. 1.Department of ZoologyUniversity of WisconsinMadisonUSA
  2. 2.Department of BiologyWinona State UniversityWinonaUSA

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