Fig. 4. Swimming directions and patterns of larvae with anterior (A) and posterior (B) pigment cells ablated in the x-y plane. (A) The ablation of the anterior pigment cell greatly reduced upward swimming (N=69). (B) Upward swimming of the larvae with posterior pigment cells ablated was not affected (N=56). Both pigment cell-ablated larvae followed similar swimming paths; straight (open circle), spiral (open triangle), curved (solid circle) and random (solid triangle). The shaded area represents 45° from the y axis (see Fig. 5).