Origin, diversity, and biogeography of Antarctic scale worms (Polychaeta: Polynoidae): a wide-scale barcoding approach

Aim: The Antarctic marine environment hosts diversified and highly endemic benthos owing to its unique geologic and climatic history. Current warming trends have increased the urgency of understanding Antarctic species history to predict how environmental changes will impact ecosystem functioning. Antarctic benthic lineages have traditionally been examined under three hypotheses: 1) high endemism and local radiation, 2) emergence of deep-sea taxa through thermohaline circulation, 3) species migrations across the Polar Front. In this study, we investigated which hypotheses best describe benthic invertebrate origins by examining Antarctic scale worms.
Location: Southern Ocean, Kerguelen archipelago, South American peninsula, Indian Ocean, New Zealand.
Taxon: Scale worm polychaetes (Polynoidae).
Methods: We amassed 670 polynoids from the Southern Ocean and neighbouring areas and performed phylogenetic reconstructions to identify lineages across geographic regions, aided by mitochondrial ma...