Movie S1. Fixation of granuloreticulopodia of Amphistegina lessonii d’Orbigny. Granuloreticulopodia contained a large number of rapidly moving granules before the addition of glutaraldehyde (up to c. 37 s. from the beginning of the recording). The movement of the granuloreticulopodia stopped after application of glutaraldehyde (c. 37-52 s. from the beginning of the recording), and granules started to gradually disappear (c. 60-320 s. from the beginning of the recording). Finally, the granuloreticulopodia were almost completely devoid of granules after c. 300 s. since application of the glutaraldehyde. Note lack of beading response during fixation.