Oxytetracycline and Florfenicol Association Affects Zebrafish Larvae Behavioral Repertoire

Oxytetracycline (OTC) and Florfenicol (FF) are prevalent antibiotics choices in both fish production and livestock farming. A comprehensive understanding of their effects is paramount for effective control of their use and for elucidating their physiological and pharmacological implications. In our investigation, zebrafish larvae were subjected to varying concentrations of OTC, FF or a combination of OTC + FF during 96 h. We observed behavioral alterations in the group exposed to OTC + FF. These fish displayed increased mobility, spent more time in the central zone, exhibited reduced turn angles, and experienced an impaired optomotor response. Coincidentally, our data provided evidence of reduced anxiety-like behavior in zebrafish larvae treated with OTC and FF, while also demonstrating the adverse effects of antibiotics on the optomotor response. Anxiety-like behavior plays an important role in species survival, acting as a key mechanism for adaptation and protection. The absence of such behavior can increase organism vulnerability in the environment. Thus, this study showed the behavioral consequences of OTC and FF exposure in zebrafish larvae, highlighting the impact of the combined toxicity of these antibiotics.