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Genotype, Fish‐Mediated Chemical, and Phototactic Behavior in Daphnia Magna
Author(s) -
De Meester Luc
Publication year - 1993
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1940075
Subject(s) - biology , daphnia , daphnia magna , phototaxis , fish <actinopterygii> , predation , zoology , ecology , toxicity , crustacean , genetics , chemistry , fishery , organic chemistry
Clones were isolated from natural populations with contrasting fish predation pressure and were tested for their phototactic behavior in the presence and absence of fish and/or fish—mediated chemicals. The presence of fish—mediated chemicals induced a more negatively phototactic behavior in all clones tested. This response was observed within 24 h after exposure to these chemicals. Release from the presence of the fish—mediated chemicals resulted for most clones in a gradual change back to control behavior, which took several days. There was no indication of a maternal effect. The response was not enhanced by a more direct exposure to the presence of fish, suggesting that the stimulus is a chemical. The results indicated genetic differences in responsiveness to fish—mediated chemicals in Daphnia. Clones isolated from habitats in which fish were present were on average more responsive than clones isolated from a fishless habitat. Significant genetic differences in phototactic behavior between the clones tested could be observed in the presence as well as in the absence of fish—mediated chemicals.