Marpissa muscosa or fence post jumping spider is a spider in the same family as the zebra spider. As I mentioned in the post of the zebra spider, jumping spiders have excellent visual skills. One of the things I noticed when editing the pictures was that it has eyes on the sides, just above the first and second leg pair. Looks pretty weird! They also have two larger eyes in the front and two smaller eyes next to the bigger ones. ‘My’ spider wasn’t really in the mood for posing, so I haven’t been able to take a picture of its face. But what do spiders do with all these eyes? Jumping spiders use their biggest eyes for zooming in on their prey and maintain a close eye on the target when jumping. These eyes also provide binocular and colour vision. This is pretty rare for a spider. As they actively hunt and not build webs, the other eyes are very useful for detecting motion like from prey and predators from every angle. Research in another hunting spider has shown that the middle front eyes are used for target discrimination and the eyes on the sides are used for target detection. So in essence, spiders have separate eyes for the different visual elements.
Next to excellent vision, jumping spiders have great cognitive abilities. Scientists found that the fence post jumping spider is able to learn certain rules that if followed lead to food. In the experiments, scientists trained Marpissa muscosa spiders to learn that a certain colour (yellow or blue) and/or location (left or right side of the test area) indicated a delicious food reward. Later on, the rules were reversed. According to the findings, most M. muscosa spiders are able to learn rules and adapt to them very quick. Rule reversal also did not pose problems for the spiders. The fact that spiders don’t have elaborate brains (and thus not much resources for plasticity in their brains) or long lifespans, makes this a remarkable finding.
These past few years, scientists have started to conduct more research on the behaviour and cognition of spiders. They made spiders run on a treadmill (!) and created virtual reality experiments for spiders to partake in. Yes, scientists can be pretty weird! But I do hope they find out more on how spiders live. Perhaps we humans can learn a thing or two from spiders! 🙂