Both authors contributed equally to the work.
Expanding hybrid zone between Solea aegyptiaca and Solea senegalensis: genetic evidence over two decades
Article first published online: 22 MAR 2011
© 2011 Blackwell Publishing Ltd
Volume 20, Issue 8, pages 1717–1728, April 2011
How to Cite
OUANES, K., BAHRI-SFAR, L., BEN HASSINE, O. K. and BONHOMME, F. (2011), Expanding hybrid zone between Solea aegyptiaca and Solea senegalensis: genetic evidence over two decades. Molecular Ecology, 20: 1717–1728. doi: 10.1111/j.1365-294X.2011.05034.x
- Issue published online: 5 APR 2011
- Article first published online: 22 MAR 2011
- Received 23 December 2009; revision received 25 November 2010; accepted 28 November 2010
- hybrid zone;
- Solea aegyptiaca;
- Solea senegalensis;
- tension zone
Several marine hybrid zones have been described and studied during the last years. Assessing the movements of extending hybrid zones is central to improve our understanding of evolutionary processes. We have re-examined the hybrid zone between Solea aegyptiaca and Solea senegalensis that was first described 22 years ago in northern Tunisia when introgressed S. senegalensis individuals were found in the Gulf of Tunis, whereas locally caught S. aegyptiaca were genetically pure. Six population samples harvested both inside and outside the area where the two fish species coexist were genotyped for allozymes and exon-primed intron length polymorphism. Both types of markers were congruent and revealed that introgression takes place indeed in both directions. A high introgression level (36.4%) in the Bizerta lagoon and much less outside indicate that this is the main area where hybridization occurs while introgression clines towards the south in S. aegyptiaca and towards the north in S. senegalensis plead in favour of the existence of a unimodal hybrid zone. The higher introgression level calculated in the current study (when compared to 16% reported formerly) and the newly found introgressed S. aegyptiaca in Bizerta lagoon seem to indicate that the genetic exchanges occurring between the two taxa are evolving and not stabilized yet.