Jumping Spiders

Jumping spiders, belong to the Salticidae family and are known for their good eyesight as well for their jumping. They can be found in tropical forests, temperate forests, deserts, intertidal zone and even in mountains. Many of them are very colorful(the males are more colorful than the females).They have a rectangular thorax, short legs, and a distinctive eye arrangement: they typically have eight eyes arranged in three or four rows. The front, and most distinctive row, is enlarged and forward facing to enable sterioscopic vision. The others are situated back on the cephalotorax.
These spiders have an eyesight that is sensitive to ultraviolet and green light. A recent study, led by Daiqin Li, at the National University of Singapore, showed how important UV light was to jumping spiders’ courtship and mating. In the presence of UV light the males show fluorescent patches of scales on the face and body, while the females give off green fluorescent light from their palps. In an article wroten by Aalok Mehta: “Li speculates that the behaviour may have evolved as a way for the spiders to signal their suitability as mates while minimizing unwanted attraction from predators. But it's still dangerous, since many spider predators, such as some birds, can see UV light". In order to study this UV-induced fluorescence communication in jumping spiders, the team did a series of experiments in which they placed some of these spiders under different light conditions, and observed their behavior. They have come to the conclusion that under full-spectrum light, including UV, males and females began courtship rituals; without UV light, females turned away and males paid less attention to the girls; when males were placed in UV light and females were not, the females could see the reflection from the males and performed their normal courting behaviour; but 16 of 20 males ignored the females, who were not reflecting UV light.