Live animals, especially when in a group of conspecifics, can hardly be forced to change their behaviors as intended by the experimenter. Hence, experimental manipulations are difficult and often lacking to underpin proposed theoretical assumptions on collective movement, decision-making or leadership. One elegant solution is to replace live individuals in a group by biomimetic robots. In a multidisciplinary group, we thus developed an interactive fish robot – the so-called RoboFish.
Through the interactive behaviors based on real time tracking of the fish shoal, our system can be adjusted to imitate different individual characteristics of live fish and is accepted as a conspecific by live guppies (Poecilia reticulata). This allows us to use RoboFish to investigate many different ethological questions.
Social interactions in many fish species rely mostly on visual cues. However, some fish species colonized habitats where visual cues are omitted. In the South of Mexico, surface-dwelling mollies (Poecilia mexicana) successfully invaded caves and adapted to dark conditions. While almost colorless, these cave mollies possess smaller but still functional eyes. Although previous studies found cave mollies to show reduced shoaling preferences with conspecifics in light it is assumed that they possess specialized adaptations to maintain some kind of sociality also in their dark habitats