Maturation of polarization and luminance contrast sensitivities in cuttlefish (Sepia officinalis)

Abstract

Summary Polarization sensitivity (PS) is a characteristic of the visual system of cephalopods. It has been well documented in adult cuttlefish which use PS in a large range of tasks such as communication, orientation and predation. Since cuttlefish do not benefit from parental care, their visual system and motion detection ability need to be efficient from hatching to enable them to detect prey or predators. We studied the maturation and functionality of polarization sensitivity in newly hatched cuttlefish. In a first experiment, we examined the response of juvenile cuttlefish from hatching to the age of one month, towards a moving, vertically-oriented grating (contrasting and polarized stripes) using an optomotor response apparatus. Cuttlefish showed differences in maturation of polarization vs. intensity contrast motion detection. In a second experiment, we examined the involvement of polarization information in prey preference and detection in cuttlefish of the same age. Cuttlefish chose preferentially not to attack transparent prey in which the polarization contrast has been removed with a depolarizing filter. Performances of prey detection based on intensity contrast improved with age. Polarization contrast can help cuttlefish detect transparent prey. Our results suggest that polarization is not a simple modulation of intensity information, but rather that it is processed as a distinct channel of visual information. Both intensity and polarization sensitivity are functional, though not fully matured, in newly hatched cuttlefish and seem to help in prey detection.