Octopuses and drilling snails as the main suspects of predation traces on shelled molluscs in West Antarctica

The analysis of predation traces on shelled taxa is a primary source of data for studying predator–prey interactions in both modern and past ecosystems, and provides valuable information along ecological and evolutionary timescales. For Antarctica, there is little information about predation traces on shelled taxa, and the available studies come almost entirely from fossil remains. We examined traces (holes and cracks) attributed to different predators on mollusc shells from bottom benthic communities at 15 stations in West Antarctica, at depths between 71.5 and 754 m. Based on 72 shells with signs of predation, we recognized three different patterns: one produced by drilling gastropods (most probably naticids), and two others interpreted as caused by octopuses. Our results indicate that predation traces on bivalves, which were the most common prey, are nonrandomly distributed, suggesting site selectivity by predators. Future work on predation traces by durophages on shelled Antarctic molluscs is still a pending and necessary issue.