Description of the natural activity of great scallops (Pecten maximus)

What is it about?

This study investigated the natural behaviour (gaping activity) of the great scallop (Pecten maximus) by continuously monitoring 35 individuals in several individual tanks and in situ (Bay of Saint-Brieuc, Brittany, France) using fully autonomous Hall effect sensors. Our results revealed a circadian cycle in their gaping activity, with almost all individuals exhibited nocturnal activity, with valves more open at night than during the day. In addition, there were indications that light levels strongly determine scallop activity.

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Photo by Jannet Serhan on Unsplash

Photo by Jannet Serhan on Unsplash

Why is it important?

This knowledge of the natural activity of bivalves (i.e. not exposed to stressful environmental variations) will serve as a baseline for detecting abnormal behavior (deviations). Based on the opening status of scallops, we identified several gaping behaviors deviating from the regular daily pattern (lack of rhythmicity, high daytime opening), potentially reflecting physiological weakness. While further long-term studies are required to fully understand the natural activity of scallops, these findings pave the way for studies focused on the scallop response to external factors and introduce further research into the detection of abnormal behaviors. From a technical perspective, our field-based monitoring demonstrates the suitability of autonomous valvometry sensors for studying mobile subtidal bivalve activity in remote offshore environments.