Cecilia Karlsson

D.Phil Student


I am a jointly BBSRC and St. John’s College (Lamb and Flag scholarship) funded DPhil student on the Interdisciplinary Bioscience DTP.

My research explores the sensory basis of distance estimation in teleost fish as part of a path integration navigation system. Path integration, the ability of an animal to keep track of its distance and direction travelled such that it can at any time compute a shortcut back to an origin, has never been studied in teleost fish. One of my current projects is to develop a behavioural task to demonstrate this form of navigation in fish, using the blind and sighted morphs of the Mexican cavefish, Astyanax fasciatus, as my study species. The second part of my research is focused on the distance estimation component required for path integration. I am using the Picasso Triggerfish, Rhinecanthus aculeatus, in behavioural experiments to test whether or not fish can estimate distance, and what sensory mechanisms they use to do so. Terrestrial animals have been shown to use a combination of stride integration, vestibular cues, and optic flow to estimate distance. However, fish present an interesting study system because of the habitat they live in: sighted fish are able to extract visual information from their background in a similar way to terrestrial species, but also hydrodynamic information from the medium they swim through using their lateral line. I am therefore exploring how optic flow and water flow information may interact in the odometer of fish.


I obtained my BSc(Hons) in Biological Sciences in 2015 from the University of Oxford (Lady Margaret Hall) and began my PhD that year, moving to St John’s College. I started researching path integration and distance estimation as part of my Final Honour School project looking at three dimensional distance estimation in humans in 2014/15.


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