Évaluation de la validité du marquage LF RFID et des préférences visuelles au sein d'un banc de poissons à l'aide d'un simple T-maze chez le zebrafish (Danio rerio)

Abstract

Nowadays, zebrafish (Danio rerio) is a fish widely used as a model in many fields of research such as neurophysiology, genetics or embryonic development. This social species living in schools is also able to make simple associations, thus forming a comprehensive model to study behavior. In this context, learning experiments based on visual stimuli are common and the use of electronic technology of individual identification by RFID in this species and its effects on learning abilities and tag loss are not scientifically assessed, their consequences on behavior and variation factors are often overlooked. Moreover, visual preferences and variation factors are rarely taken into account in the studies’ methodology and results’ interpretation although they are subjected to contradictions in the litterature. Therefore, in the light of the lack of consistency of preferences for visual stimuli and in the view of the lack of studies addressing the consequences of the injection of a tag, this study aims to evaluate those aspects in order to improve the creation of protocols based on visual stimuli as well as to assess the validity of the use of a Loligo tag. Thanks to a simple T-maze, we worked with the zebrafish (Danio rerio) as a biological model. In order to study visual preferences, we confronted pairs of colors or patterns in a T-maze. We also varied the group sizes in these experiments to measure the behavioral differences according to social context for preferences. For the evaluation of the consequences of the Loligo tag, fifty zebrafish were tagged and the rate of tag loss and mortality were measured during 100 days. Moreover, we also evaluated the impact of this tag on visual preferences and learning abilities. Results show that, although we can not confirm that its injection impacts learning abilities, its validity is questioned in zebrafish because it causes a significantly higher rate of tag loss compared to a lighter tag. Preferences for particular colors and patterns were also highlighted through this study, as well as preference differences linked to social context when zebrafish were tested by pairs or alone.