Genetic structure and connectivity of the critically endangered deep-sea
octocoral Isidella elongata (Esper, 1788): implications for marine
biodiversity conservation in the Mediterranean Sea
Abstract
The protection of the Vulnerable Marine Ecosystem identified by the
presence of the critically endangered bamboo coral Isidella elongata has
been recognized as an urgent task. Although some research has focused on
its spatial distribution, there is no available information on this
species connectivity and genetic structure. This study aims to
investigate, for the first time, the genetic diversity pattern and the
inter-population connectivity of I. elongata at the Mediterranean scale.
A DNA-based approach was used to assess the genetic diversity of 33 I.
elongata samples collected in six different areas using two
mitochondrial genes (COI and MutS), and a nuclear one (ITS2). Molecular
results confirmed that all samples belonged to I. elongata and showed a
scarce level of intra- and inter-populational mtDNA differentiation,
whereas nuDNA data showed higher genetic structuring. Furthermore, a
Lagrangian model (forward-in-time simulations) was used to investigate
the species larval connectivity under different sea currents conditions.
Our results suggest the presence of persistent pathways, supporting the
self-sustaining nature of the populations, especially in the central
Mediterranean Sea. This study finding are discussed in light of the
implementation of management measures encompassing both the conservation
of vulnerable species and the sustainability of deep-water fisheries.