Despite
their cosmopolitan occurrence and massive plankton sampling during
expeditions, the genetic diversity within Pteropoda Cuvier, 1804 is
still largely unexplored. In this study we present a next-generation
environmental barcoding approach to zooplankton bulk samples, which were
collected during the circumglobal 2010 Malaspina expedition to evaluate
pteropod diversity. We introduce a technique that avoids destructive
procedures and leaves material intact for further morphological
investigations. We extracted DNA out of the dregs (organic material such
as mucus or body parts) of 27 sample containers for molecular barcoding
(average 100-260 bp of COI). We were able to identify 7128 operational
taxonomic units corresponding to the species composition contained in
the examined samples. Among them were three species of thecosome
pteropods, Creseis acicula, Creseis virgula and Cavolinia inflexa,
which are discussed with respect to their taxonomy and their geographic
distribution. Unidentified gymnosomes were also present in our samples
from warmer regions in oceanic waters of the southern Indian Ocean. To
facilitate identification of species, it is beneficial to create a
better database of pteropod COI barcodes. Furthermore, gathering
environmental barcoding data on a broad global scale will help to better
understand species abundance and distribution of pteropods in the
world’s oceans, and potentially those of other planktonic organisms. |