Molecular systematics of the genus Holothuria in the Mediterranean and Northeastern Atlantic and a molecular clock for the diversification of the Holothuriidae (Echinodermata: Holothuroidea)

This work investigates the systematics of the genus Holothuria in the Mediterranean Sea and Northeastern Atlantic in the light of a wider molecular phylogenetic hypothesis of Holothuriidae, and it also provides a time-scale for the family diversification using mitochondrial markers and the molecular clock hypothesis. The subgenera Holothuria and Roweothuria are retrieved as paraphyletic. At least four separate lineages, with quite different time frameworks were identified. There are at least three species with an apparent long evolutionary history, H. forskali, H. sanctori and H. impatiens and six species belonging to Holothuria, Roweothuria and Vaneyothuria, which have diverged relatively recently.

Research highlights► Holothuria and Roweothuria subgenera were retrieved as paraphyletic. ► Four lineages with quite different time frameworks were identified in the Mediterranean Sea and Northeastern Atlantic. ► At least three species (H. forskali, H. sanctori and H. impatiens) showed an apparent long evolutionary history. ► Six species belonging to Holothuria, Roweothuria and Vaneyothuria have diverged relatively recently.