The sea urchin Diadema africanum uses low resolution vision to find shelter and deter enemies
Many sea urchins can detect light on their body surface and some species are reported to possess image-resolving vision. Here, we measure the spatial resolution of vision in the long-spined sea urchin Diadema africanum, using two different visual responses: a taxis towards dark objects and an alarm response of spine-pointing towards looming stimuli. For the taxis response we used visual stimuli, w
