COLOUR-BASED SEXUAL SELECTION IN A GENUS OF JUMPING SPIDER SILER (ARANEAE: SALTICIDAE)

Abstract

Sexual dichromatism is a form of sexual dimorphism that conspecific males and females differ in body colour. While in many cases, males are bright and females are drab, mutual ornamentation is also not uncommon. However, the evolution of mutual ornamentation remains largely unexplored. In this thesis, I tested the hypothesis that mutual sexual selection drives the evolution and maintenance of mutual ornamentation using jumping spider genus Siler. I first quantified the extent of sexual dichromatism in Siler using the approaches independent and dependent of the receiver’s perspective. The results revealed an overall colour differences between Siler males and females. I next investigated the functional role of colour in mutual selection using two Siler species. I found that mutual mate choice selected for mutual ornamentation, and conspicuous colour mediated intra-sexual competition in Siler salticids. Overall, these findings provide new insights into the function and evolution of mutual ornamentation in arthropods.