Abstract:
In anticipation of the current biodiversity crisis, it has become critical to rapidly and
accurately assess biodiversity. DNA barcoding has proved efficient in facilitating the
discovery and description of thousands of species and also provides insight into the
dynamics of biodiversity. Here, we sequenced a portion of the mitochondrial
cytochrome
c oxidase subunit I (COI) gene from all morphospecies of reef brittle stars
collected during a large-scale
biodiversity survey in the southwestern Indian Ocean
(SWIO). Three methods of species delineation (Automatic Barcode Gap Discovery,
Generalized Mixed Yule Coalescent model, and Bayesian Poisson Tree Processes)
showed concordant results and revealed 51 shallow reef species in the region. Mean
intraspecific genetic distances (0.005–0.064) and mean interspecific genetic distances
within genera (0.056–0.316) were concordant with previous echinoderm studies. This
study revealed that brittle-star
biodiversity is underestimated by 20% within SWIO
and by >40% when including specimens from the Pacific Ocean. Results are discussed
in terms of endemism, diversification processes, and conservation implications for the
Indo-West
Pacific marine biodiversity. We emphasize the need to further our knowledge
on biodiversity of invertebrate groups in peripheral areas.
