This study examines the effects of body size variation on the optical properties of the compound eyes of visually guided desert ants belonging to the genus Cataglyphis. Although linear head size may vary by a factor of 2 within conspecific workers and most optical parameters change accordingly, the extent of the visual field remains constant. Comparative measurements carried out on workers of three species (C. albicans, C. bicolor and C. fortis) and on reproductive females and males of one species (C. bicolor) show that the form (size and shape) of the visual field is highly characteristic for each caste/species. A constant visual field is realised by reciprocal scaling rules for the number of ommatidia and the angular spacing of ommatidia. While larger ants have more ommatidia per compound eye, interommatidial angles are reduced accordingly, thus giving rise to a constant visual field. Among conspecific ant workers, the relationship between spatial visual acuity and eye size is similar to that found in interspecific comparisons and reflects optical constraints imposed on the design of the compound eye. Mapping of spatial visual directions onto the compound eye surface reveals a characteristic, inhomogeneous distribution of interommatidial spacing, particularly a foveal band with increased visual acuity in the vertical direction. This 'visual stretch' viewing the horizon is similar to that found in a variety of flying insects. Although, among conspecific workers, both the number of ommatidia and the interommatidial angles vary with varying head size, the overall pattern of interommatidial spacing is maintained so that corresponding positions on the compound eye of small and large individuals look in equivalent directions in space. These findings are in accordance with the observation that the shape of the compound eye surface, as expressed by the radius of curvature along cross sections, is similar in small and large ants.
Optical scaling in conspecific Cataglyphis ants
C Zollikofer, R Wehner, T Fukushi; Optical scaling in conspecific Cataglyphis ants. J Exp Biol 1 January 1995; 198 (8): 1637–1646. doi: https://doi.org/10.1242/jeb.198.8.1637
Download citation file:
Advertisement
Cited by
In the field: an interview with Martha Muñoz

Martha Muñoz is an Assistant Professor at Yale University, investigating the evolutionary biology of anole lizards and lungless salamanders. In our new Conversation, she talks about her fieldwork in Indonesia, Costa Rica, the Dominican Republic and the Appalachian Mountains, including a death-defying dash to the top of a mountain through an approaching hurricane.
Graham Scott in conversation with Big Biology

Graham Scott talks to Big Biology about the oxygen cascade in mice living on mountaintops, extreme environments for such small organisms. In this JEB-sponsored episode, they discuss the concept of symmorphosis and the evolution of the oxygen cascade.
Propose a new Workshop
-GSWorkshop.png?versionId=3846)
Our Workshops bring together leading experts and early-career researchers from a range of scientific backgrounds. Applications are now open to propose Workshops for 2024, one of which will be held in a Global South country.
Manipulation of mitochondrial function affects red carotenoid metabolism in a marine copepod

Tigriopus californicus copepods with the most powerful mitochondria are the brightest red, providing an honest and direct link between the attractiveness of a creature and their metabolic prowess.
The physiological cost of colour change

In their Review, Ateah Alfakih, Penelope Watt and Nicola Nadeau discuss the energetic cost of colour change and highlight how this can be avoided or lessened in animals that change colour rapidly or slowly.