How Far Can The Golden Mussel (Limnoperna Fortunei - Mytilidae) Go With Its Own Foot?

Limnoperna fortunei (golden mussel) displays significant invasive potential and can lead to economic and environmental damage. The aim of this study is to describe the ontogenetical circadian pattern of activity of golden mussel using laboratory experiments. Golden mussels were split into two size groups: small (<15 mm) and large (>=15 mm). The movement pattern of each size group was filmed. Experiments were carried out in two distinct periods: light-dark experiments comprising 9 hours under a bright light followed by 13 hours under a red light and dark-light experiments consisting of 13 hours under a red light followed by 9 hours under a bright light. The variables course and speed were tested using size (small and large) and experiments (light-dark and dark-light) as factors. Both small and large mussels were more active in the first eight hours of the experiments, but no differences were observed regarding course and speed between the experiments. The period of the day did not influence the activity or distance patterns traveled by golden mussels, although small golden mussels presented significantly higher mean course and speed significantly compared to large mussels. Small individuals also displace faster than large individuals, resulting in longer traveled distances.