Movie 1

Ciliary arrest response in Ciona. Oral siphon of a Ciona juvenile having two pairs of stigmata was stimulated by a glass needle (left). Immediately after the needle touched inner surface of the oral siphon, all the cilia on stigmata stopped beating at once and leaned back to inside of the pharyngeal cavity. Ciliary arrest continued about 7.5 s in this case (see time indicator).