Can you see it? Polarized light stimuli startle goldfish

OTERO CORONEL, SANTIAGO; BERÓN DE ASTRADA, MARTÍN; MEDAN, VIOLETA

Mar del Plata

Congreso; 30va Reunión anual de la Sociedad Argentina de Neurociencias; 2015

Sociedad Argentina de Neurociencias

Aquatic environments are rich in polarized light patterns, creating a backgroundpolarization field against which objects, which diffuse or differentially reflect polarizedlight, can be viewed. To an animal with a visual system sensitive to polarized light such ascommon goldfish, Carassius auratus, these cues could provide valuable information aboutits environment and be used for navigation and object detection.To test to which extent their polarization sensitivity has behavioral significance, werecorded their startle response (C-start) in response to an expanding disc (loom) in twosituations: 1) intensity contrast, where a black disc expanded on a white background and 2)polarized light contrast, where the background light was linearly polarized and the loomwas elliptically polarized. These last stimuli were projected with a modified LCD screen. Thequestion under scrutiny is if stimuli where the only source of contrast is the polarizationangle between object and background (no intensity contrast) are conspicuous enough totrigger a startle reaction.Preliminary results show that polarized light contrast stimuli are salient enough to trigger aC-start although with a smaller probability (40% vs. 100% for intensity contrast stimuli).The results are discussed in the context of the different sources of visual informationavailable and the relative contributions of different properties of light for threat detection.