2.4. Video and image analysis
Videos of the larvae’s locomotor response were analyzed using Kinovea, an open-source software (www.kinovea.org, France) to determine the RD and TBF, as reported in Eq. 1 and 2. The automatic point tracking feature within Kinovea facilitated tail tracking, producing an Excel file (Microsoft Corp., WA, USA) of the tail tip coordinates. Every video frame was double checked to ensure that the software accurately tracked the tail position. Manual adjustment was applied as necessary if low-resolution images due to fast tail motion hindered the automatic tail tip detection process. Any small tail flicks were not included to be consistent with the methods reported in the literature[16,34].
\(Response\ Duration\ (RD)=Movement\ End\ Time-Movement\ Start\ Time\ \)