Miniaturisation in ants affects their vision and visual navigation
Ravindra Palavalli-Nettimi , Ravindra Palavalli-Nettimi , Ajay Narendra
Department of Biological Sciences, Macquarie University, Sydney; Department of Biological Sciences, Macquarie University, Sydney ; Department of Biological Sciences, Macquarie University, Sydney
Evolution of extremely small body size in a lineage, reduction beyond which is not possible, is a phenomenon called miniaturisation. It has dramatic effects on an animal’s ecology, anatomy, morphology and physiology. Miniaturisation has captivated biologists' imagination because tissues and organs reach limits imposed by the physical world, leading to alternative behavioural strategies. But the behavioural cost of miniaturisation has largely remained unexplored. Here we study ants that exhibit dramatic variation in body size where irrespective of size, they all have a unifying behaviour: to find their way back home. We quantify the variation in the number of ommatidia between ants of different sizes. Using pattern electroretinography, we tested whether the reduction in size affects spatial acuity and contrast sensitivity. Ants derive compass information from the pattern of polarised skylight. They detect this through specialised ommatidia located in the dorsal rim region of their eye. We tested whether the number of specialised ommatidia scales with the total number of ommatidia in various ants and whether this relates to the ability of animals to navigate using the pattern of polarised skylight. In addition, we tested how miniaturisation in ants affects navigational abilities such as obstacle avoidance. This poster will provide an overview of how miniaturisation in ants affects vision and visual navigation behaviours.