News story by Aryaa Sinha
21 July, USA: A new study published in PLOS Biology of Harvard University shows jumping spiders use their peripheral vision (ability to see objects and movements outside the direct line of vision) to distinguish between objects and living creatures. The ability to detect other living creatures in our surrounding is an important skill for animals for finding mates, avoiding predators, catching prey, and so on. Scientists have known for long that most vertebrates (animals having backbone) can quickly notice this pattern. To inspect this phenomenon in invertebrates, the researchers caught 60 jumping spiders (Menemerus Semilimbatus) on a round trendmill. On either side of the treadmill, video screens flashed patterns of light that were only visible to outside eyes. Some of the patterns were random while some others mimicked movement patterns of animals. It was found that spiders would prefer to face the random patterns than those showing animal movement patterns. This was contradictory to the belief that spiders should focus on objects that appear to be living. Researchers explain that the spiders do this to focus on movement they don’t recognize, and investigate, rather than seeing organismal movement that they already recognize.
