New funded PhD project: Crustacean vision

THIS POSITION IS NO LONGER AVAILABLE: Crustacean vision: adaptable eyes for extreme changes in light – Martin J How

Photographers are familiar with the idea of controlling exposure by adjusting shutter speed and aperture, thus altering the amount of light that hits the camera chip. Most complex animal eyes have evolved to do something similar. For example, in humans the size of the iris and the sensitivity of the underlying light receptors and neurons can be quickly tuned, thereby allowing us to see in light levels varying by over 100 million times, from dark starlit nights to bright sunny days.

Crustaceans are no exception. Their compound eyes are composed of hundreds, or sometimes thousands, of repeated eye units (ommatidia) each viewing a different area in the world around. Each one of these ommatidia needs to adapt to local light conditions and does this using a system of moveable screening pigments within the light-sensitive cells. The intricacies of how crustaceans deal with rapidly changing light environments is not well understood. For example, many species (such as fiddler crabs) have eyes with very wide fields of view. This means that, while part of the eye could be experiencing very high light levels (e.g. in the direction of the sun), another part could be in the dark. How eyes simultaneously adapt different parts of their eyes to different light levels is relatively unknown. There are also suggestions that light adaptation in the eye of fiddler crabs could alter their sensitivity to the polarization of light.

This project will address key questions around how crustacean eyes deal with changing light levels. The student will take a multi-scale approach using a wide range of techniques, ranging from micro-anatomical studies using electron microscopy, through to behavioural experiments in the animal’s natural environment in Spain, Panama, and Australia.  

The student will join the Ecology of Vision Group ( at the School of Biological Sciences, University of Bristol, under the supervision of Dr Martin How and Dr Nicholas Roberts. The group currently hosts one principal investigator, two research fellows, two postdocs, and four PhD students, all working on diverse aspects of animal visual ecology.

Eligibility criteria: At least an upper second-class honours degree (e.g. MSci) or equivalent. Applicants with a good BSc degree may be considered if they can demonstrate very good potential for research. A keen interest in animal sensory ecology is essential, as well as demonstrable lab and fieldwork skills.

Scholarship details: This studentship is fully funded by the Royal Society, covering full UK/EU PhD tuition fees, research costs, and an annual stipend of £14,057. This award is available to UK/EU applicants only, unless suitable top-up funding can be identified for international candidates. If English is not your first language, you must have IELTS 6.5, or equivalent. 

Start date: March-Sept 2016

Informal enquiries: Dr Martin J How (

Application Details: To apply for this studentship submit a PhD application using our online application system [