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Sex Ratio Variation in the Intertidal Isopod, Jaera Albifrons

Published online by Cambridge University Press:  11 May 2009

Stuart B. Piertney
Affiliation:
Marine and Fisheries Genetics Laboratory, School of Biological Sciences, University College of Swansea, Singleton Park, Swansea, SA2 8PP.
Gary R. Carvalho
Affiliation:
Marine and Fisheries Genetics Laboratory, School of Biological Sciences, University College of Swansea, Singleton Park, Swansea, SA2 8PP.

Extract

Thirty ‘rock-populations’ of the intertidal isopod, Jaera albifrons (Isopoda: Asellota), from South Wales area were found to display a significant and persistent sex ratio bias, with females outnumbering males by up to 12 to 1. This thelygeny was not mirrored in broods that were isolated in aquaria after insemination, nor in broods that developed under various temperature and light regimes. Such a discrepancy suggests that the mechanism generating sex ratio biases in natural populations is not innate, nor is influenced by cytoplasmic or environmental factors. The possible causes of thelygeny in natural populations are discussed.

Type
Short Communications
Copyright
Copyright © Marine Biological Association of the United Kingdom 1996

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