Development and Evolution of Spider Eyes

Spiders are a diverse order of chelicerates with over 50,000 describe species distributed across most habitats on earth. These successful predators have multiocular visual systems and exhibit great diversity in the number, size and placement of their eyes reflecting environmental and behavioural adaptations. The ground plan of spider eyes is four pairs of two types: the principal eyes (anterior median eyes), which likely share evolutionary origins with insect ocelli, and the secondary eyes (anterior lateral, posterior median, and posterior lateral Eyes), related to insect compound eyes.

While Pax6 genes initiate the development of eyes in most animals this is not the case in spiders and indeed little is known about how spider eye specification is first initiated and how the developmental programme that generates the spider eye ground plan has evolved to give rise to different eye arrangements among spiders. To better understand the diverse multi-ocular visual systems of spiders, this project will investigate the development, evolution and function of spider eyes through the following Objectives.

Objective 1. How is spider eye development initiated? Objective 2. How are differences in spider eye size among species regulated? Objective 3. What is the basis of differences in eye number among spider species? Objective 4. How do differences in spider eye arrangements affect the vision of these animals?