According to Ronald Hoy, a professor of neurobiology and behavior at Cornell University, jumping spiders are one of the smartest invertebrates, despite having a brain the size of a poppy-seed (less than a millimeter in diameter). Instead of making a sticky web to catch their prey, jumping spiders find their victims, stalk them and then jump on them. What enables jumping spiders to have such precise hunting behaviors? Jumping spiders have a unique visual system which collects information from 2 large eyes which specialize in high-resolution vision, and 6 smaller eyes which detect motion. This visual system essentially gives them a 360-degree view of their surroundings. However, little is known about the neural mechanisms behind the visual brain areas of jumping spiders. This lack of information has stemmed from the fact that, until recently, there was no way to insert an electrode into a spider’s brain without causing inner fluids to squirt out, which ultimately kills the spider.
A group of Cornell University researchers (G. Menda., et. al., 2014) developed a way to gain access to jumping spiders’ nervous system without causing catastrophic fluid loss. This technique has allowed us to gain a better understanding of the neural basis behind jumping spiders’ special visual network. The researchers took recordings of the spiders’ brains while they watched videos of naturalistic things like prey and other spiders. They discovered a neuron that seemed to “integrat[e] the information from the spider’s two independent set of eyes, a computation that might be expected to involve a network of brain cells” (Gorman). Prey-like objects, such as flies, caused bursts of excitation from single cells. Although jumping spiders have only a fraction of the number of neurons of mammalian brains, they behave much more like mammals than spiders. Even though their brains are minuscule, their visual brain areas allow them to take part in precise hunting behaviors.
G. Menda., et. al., (2014). Visual perception in the brain of a jumping spider. Current Biology, 24, 2580-2585.
Gorman, James. “Unexpected Complexity in a Spider’s Tiny Brain.” The New York Times. The New York Times, 03 Nov. 2014. Web. 10 Apr. 2015. <http://www.nytimes.com/2014/11/04/science/mapping-the-tiny-brain-of-the-aristocrat-of-arachnids.html>.
S. Heinze, (2014). Neurobiology: Jumping spiders getting on board. Current Biology, 24, R1042-R1044.