Mito-nuclear discordance in West African mangrove crab species (Decapoda: Brachyura: Sesarmidae) suggests uni-directional mitochondrial introgression, despite prolonged evolutionary independence

ABSTRACT

Mitochondrial introgression is known as one of the major causes of misleading relationships and mito-nuclear discordance in phylogenetic analyses. It appears to be a quite widespread phenomenon in different animal taxa, with most records among vertebrates and insects. So far, in brachyuran crabs such reports of introgression are relatively infrequent. In the present study, we report such a case occurring among Central and West African mangrove crabs, using a multi-locus genetic approach. Our mito-nuclear phylogenetic comparison suggests a mitochondrial introgression between two sesarmid crab species. Based on our preliminary evidence, it seems that the mitochondrial genome of Guinearma alberti has been transferred to representatives of G. huzardi through introgression. These two species have a wide sympatric distribution along the West African coast and are considered to be congeneric based on their relatively close phylogenetic relationship.

KEYWORDS:

• Guinearma huzardi
• G. alberti
• COX1
• 16S
• NaK
• ITS1

Acknowledgements

Some Cameroonian specimens were kindly contributed by Vanessa Massou. Samples from Ghana were collected by the last author, where he was accompanied in the field by the local guide Cinquanta and by Klaus Duffner. The collecting in Ghana was partly funded and supported by Darryl L. Felder, while CDS was working as a postdoc fellow at the University of Louisiana in Lafayette (USA). Finally we thank Theresa Süß for providing assistance in the laboratory of the University of Regensburg.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

No specific grant was received for this study.