A Practical Approach for Sexing Zebrafish, Danio rerio

Abstract

This study aimed at a simple, rapid, reliable, practical, and non-destructive sexing technique for mature zebrafish (0.61 ± 0.011 g each). In the first experiment, 36 fish of each sex were selected on the basis of the presence of a prominent genital papilla on mature females and bred randomly. All the couples laid fertilized eggs with a mean fecundity of 304 eggs per female, for a 100% sexing accuracy. In the second experiment, 140 mature zebrafish were randomly selected and individually sexed like in the first experiment. Each fish was then dissected in order to confirm the reliability of this sexing technique through the observation of either the ovaries or the testes. Upon dissection, an accuracy of 100% was recorded. This study demonstrates that sexing mature zebrafish only on the basis of the presence of a prominent genital papilla on the mature female is a reliable technique.

Keywords:

• Genital papilla
• sexing technique
• zebrafish

Notes

This study was funded by the Natural Sciences and Engineering Research Council of Canada. We would like to thank the Center for Advanced Research in Environmental Genomics (CAREG), Department de Biology, University of Ottawa (Canada), for supplying the fish used in this experiment. We would also like to express our profound gratitude to all the staff of the Regional Laboratory of Aquatic Sciences (LARSA) of the Université Laval for their invaluable assistance in rearing the zebrafish used in the current study.