Cosmophasis umbratica
Cosmophasis umbratica is a species of jumping spider that occurs from India to Sumatra.
They are most frequently spotted on plants that are exposed to sunlight during later morning and early afternoon.
Males have complex iridescent markings on the dorsal and lateral cephalothorax and on the lateral femora of all legs, and silvery white lines on the abdomen, while females have a green cephalothorax and a brown, white and black abdomen.
C. umbratica shows extreme dimorphism when viewed under UV light: males reflect UV on all body parts that are displayed during intraspecific interaction, while females and juveniles do not reflect UV at all. It seems that C. umbratica uses this in sexual signaling. A similar phenomenon is found in some butterflies.Footnotes
