The induction of sexual reproduction in Daphnia magna : genetic differences between arctic and temperate populations

Even when provided with abundant food and grown in isolation, Daphnia magna from arctic Canada responds to declining photoperiods by producing male and then ephippial offspring. In contrast, clones of English origin do not alter their reproductive behaviour when exposed to photoperiod shifts. Hybrid...

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Bibliographic Details
Published in:Canadian Journal of Zoology
Main Authors: Ferrari, Denise C., Hebert, Paul D. N.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1982
Subjects:
Online Access:http://dx.doi.org/10.1139/z82-274
http://www.nrcresearchpress.com/doi/pdf/10.1139/z82-274
Description
Summary:Even when provided with abundant food and grown in isolation, Daphnia magna from arctic Canada responds to declining photoperiods by producing male and then ephippial offspring. In contrast, clones of English origin do not alter their reproductive behaviour when exposed to photoperiod shifts. Hybrid clones show an intermediate response in terms of ephippial egg production, but a variable response in male production. The results indicate that variation exists at gene loci controlling sexual behaviour in local populations as well as between distant populations. The significance of this variation is discussed in relation to the environmental heterogeneity encountered by D. magna over its extensive range.