Figure 1: Mantis shrimp eye movements.

(a) Side view of a Gonodactylus smithii. (b) Rotational degrees of freedom of stomatopod eyes relative to the external environment, as demonstrated in Odontodactylus cultrifer. Yellow arrows=pitch (up–down); green arrows=yaw (side-to-side); red arrows=torsional (roll) rotations. The midband is visible as a distinct stripe of ommatidial facets dividing the eye into dorsal and ventral hemispheres. (c,d) Series of video still frames demonstrating the torsional rotation range in G. smithii (c) and Odontodactylus scyllarus (d). (c) left eye - 45°, 85°, 0°; right eye - 30°, 20°, 90°; and (d) left eye - 90°, 80°, 0°; right eye - 90°, 0°, 90°.