Authors: Mario E Favila Janet Nolasco Ivette Chamorro Florescano Miguel Equihua
Publish Date: 2005/08/31
Volume: 59, Issue: 1, Pages: 38-
Abstract
Field observation and laboratory experiments were conducted to investigate sperm competition and patterns of sperm fertilization under different experimental conditions in the carrion ballroller beetle Canthon cyanellus cyanellus Males in nature can mate with females whose spermathecae contains fertile sperm from other males Sperm precedence was investigated using a visible genetic marker The progeny of red homozygous recessive virgin females mated once with a red male and afterward once with a green beetle homozygous dominant and vice versa revealed that regardless of its color the last male to mate fertilized ca 50 of the eggs suggesting strong sperm competition Males were able to achieve higher levels of paternity more than 80 when mated ad libitum with previously mated females although large amount of variance in paternity does not exclude the possibility of first male sperm precedence or female cryptic choice These results suggest that repeated mating and sperm replacement are the mechanisms by which last males achieve sperm precedenceWe are grateful to Ingrid Márquez for correcting the English of the original manuscript We also thank Jürgen Heinzen John Sivinsky and two anonymous referees for their valuable comments on the manuscript This study was financially supported by CONACYTMexico grant 35125VThe experiments comply with all animal care guidelines applicable in Mexico
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