Journal Club | Echolocation with Light: A New Form of Active Sensing in Fish?

Striatech hosts a series of online journal clubs, highlighting the use and the applications of our OptoDrum device. Scientists present their projects and new data, and you can learn about the latest developments in the field. There is always a Q&A session at the end.
Topic: Echolocation with Light: A New Form of Active Sensing in Fish?
Speaker: Prof. Nico K. Michiels - University of Tübingen, Germany
Description:
The brightest part of many fish species is their iris. This effect can be caused by specular reflection, light focusing and fluorescence. Why send out light from the iris? Radiating light close and parallel to the own gaze is the ideal configuration to generate and detect eyeshine in the pupils of other organisms (e.g. cat's eyes). Prof. Michiels and his team investigate the process of "active photolocation", by which the initial light sender/observer can perceive the weak light reflections in the pupils of predator and prey species.
They collect data on ocular properties (size, retinal map), contrast sensitivity and spatial acuity (Striatech's OptoDrum), spectral sensitivities of the observer (microspectrometry), spectrometric properties of all the relevant structures, and the natural light field. They also control the ability to redirect light by attaching to the fish small shading hats or transparent controls. This form of active detection is presumably functional over short distances and is used to detect otherwise highly cryptic organisms. As model system they use a small (kleiner 5 cm), active, bottom-dwelling fish species triplefin, Tripterygion delaisi. The latest results indicate that triplefins can detect gammarid crustaceans (prey) as well as scorpionfish (predator) over meaningful distances using active photolocation.
Visit Striatech's website to learn more: stria.tech/jou...