The biggest species doesn’t exceed 15 mm of length and – like miniature cats - they wander curious and stealthy among herbs and rocks. Their “military” equipment features legs and muscles which permit them to jump as high as 10-30 times their body length, they see in quadrichromy and they can resolve incredibly small details. Finally – as almost all the Spiders – they have venom to subdue preys even two-three times bigger than theirself.
We’re talking about the Jumping Spiders (Family Salticidae, comprising about 5000 species), tiny and incredible, unknown but present everywere with brilliant colors and amazing bodies.
The central nervous system, although not so complex, occupies the same portion of body volume that’s proportionally occupied by our brain. This permits them to call hunting techniques into play that are not seen in any other Arthropod. Some researchers said that – from an ethological point of view -it should be better to compare these “monsters of the Microcosm” to the big felines rather than to other Arthropods.
Some species, like the Salticids belonging to the Genus Portia and the other Spartaeinae, are able to calibrate their hunting strategy to the type of prey they are looking at. They even “invent” new strategies when they encounter a prey never seen before.
As it was not enough, they are able to memorize the spatial position of a prey and to make a “detouring” to reach the prey stealthy from behind. They can even remember the prey position for up to an hour!
The anterior median eyes are very big and they act like our fovea, with great acuteness but a restricted field of view. The other eyes, more simple, are used to widen the field of view and to detect potential moving preys from all around.
Once it becomes aware of a nearby prey, a jumping spider starts some approaching manoeuvers, more and more complex if the prey is intelligent or dangerous.
Jumping Spiders are also known for their “dances” engaged by two rivals or a courting couple. These rituals feature legs and body moving and waving. For this reason they’re often brilliantly colored. Colors are so important in the Jumping Spiders communication that two species with similar reproductive organs will not interbreed because they don’t recognize each other as belonging to the same species because of different colors. Thanks to these rituals these spiders preserve energies instead of falling in a fisical conflict.
Jumping Spiders are the most ethologically studied spiders and they deserve a great potential for future human discoveries in science and biotechnology.
