Estimating the effective level of Yucca schidigera extract for improvement of the survival, haematological parameters, immunological responses and Water quality of European seabass juveniles (dicentrarchus labrax)

•Yucca schidigera extract was for the first time to be experimented on the European seabass.•Yucca positively influenced the health status of the cultured European sea bass juveniles.•The tested levels of yucca reduced substantially the ammonia in water with no adverse effects on fish.•The welfare of Dicentrarchus labrax juveniles might be achieved at 0.75 mg L−1 yucca liquid extract.