Figure 1
Setup, experimental design and analysis methods. (a) Life cycle of Ciona intestinalis. In our lab the onset of hatching from the chorion takes place at 25 and 36 hours post fertilization (h.p.f) at 18 °C and 14 °C respectively. The onset of the light-off response in swimming larvae takes place at ca 28.5 and 43 h.p.f at 18 °C and 14 °C respectively. The onset of tail regression takes place at approximately 35 and 52 h.p.f. at 18 °C and 14 °C respectively. (b) Setup: C- camera, F- IR filter, S – ring with stimulation LED-s, T1 – Thermometer 1 measuring local temperature in the agarose, T2 – Thermometer 2 measuring cooling plate temperature, P – cooling plate, Hs – heat sink, R – PLA ring holding the arena, Ag– agarose, Ar– Arena with animals, IR – IR illumination. (c) Schematic representation of the experimental condition tested for effects on the behavioural repertoire. (d) Arena dimensions and areas used in thigmotaxis measures I- inner arena with radius 3.55 mm and O– outer thigmotaxis zone; with t = 1.45 mm the zones have equal surface area and the width of the thigmotaxis zone is above one animal body-length. (e) Examples of different local complexity of a trace. Each trajectory is coloured by local complexity which is calculated over a 3 s window and the total span of each trace is 6 s. (f) Some example trajectories of wild type animals swimming for 5 min. (g) Examples of traces spanning 50 frames based on which the current behavioural mode was calculated. In green are the 25 frames before the current time-point and in red the 25 frames later.
