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Archer Fish Can See Like Mammals
Research at Ben Gurion University of the Negev raises the question of whether orientation salience evolved differently in fish and mammals.
Credit: R.Wampers / Wikipedia
Archer fish have the ability to see objects oriented differently to the background like mammals, according to researchers from Israel's Ben Gurion University of the Negev. Led by computer scientist Ohad Ben-Shahar, the team trained archer fish to spit at images of insects on a liquid crystal display screen, then used images of two bars to represent prey objects, set against a patterned background to represent the habitat. The researchers showed the bars either both oriented in the same direction as the background pattern, both perpendicular to the pattern, or with one bar in each direction. The fish shot most often at bars oriented perpendicular to the background pattern, which suggests these objects were most visible to them.
In humans, the ability to discern the perpendicular bars is controlled by neural pathways in the visual cortex, but archer fish have no visual cortex, which means their neural mechanism may be similar to that in humans but located elsewhere in the brain, or there may be a completely different mechanism.
The researchers' paper, "Orientation Saliency Without Visual Cortex and Target Selection in Archer Fish," was published in the Proceedings of the National Academy of Sciences (PNAS).
From PhysOrg.com
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