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Population size structure and sex ratios in some woodlice (Crustacea: Oniscidae) from southern Africa

Published online by Cambridge University Press:  10 July 2009

J. M. Dangerfield
Affiliation:
Department of Biology, University of Botswana, Private Bag 0022, Gaborone, Botswana.
S. R. Telford
Affiliation:
Department of Zoology, University of Pretoria, Pretoria 0002, South Africa.

Abstract

The population size structure and adult sex ratio were recorded for four indigenous and one introduced species of terrestrial isopod from southern Africa. Interspecific variation was considerable with either discrete or continuous distributions indicative of the production of separate cohorts or continuous recruitment. Intraspecific variation was also considerable particularly in species such as Aphiloscia vilis which can be found in diverse habitats. Sex ratios were consistently female biased, a result consistent with observations made on temperate species. These observations, and a consideration of sexual dimorphism based on body mass, suggest that phenotypic plasticity may be an important tactic in the life histories of tropical woodlice and that in some populations the potential exists for strong sexual competition and complex mating systems.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1994

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References

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