The effect of ration level on the growth and survival of sub-adult tench (Tinca tinca L. 1758) in a recirculating water system

Abstract

Although tench (Tinca tinca Linnaeus 1758) has been cultured traditionally in Eurasia, Central and Southern Europe mostly by low intensity methods, investigations of the optimum intensive culture conditions for the species have recently been initiated. This work was aimed to investigate the effect of food ration level on growth and survival of sub-adult tench, under intensive culture conditions. One hundred and twenty individuals (24.55 g +/- 3.28) were fed for 102 days at three feeding levels: 0.5%, 1%, 2% b.w.d(-1). Higher body weights (b.w.) have been achieved with the 2% ration level in all experimental phases. However, by the end of the experiment (up to the b.w. of 34 g), fish fed with the ration level of 1% b.w.d(-1) resulted in better indices (FCR, SGR, % weight gain). These findings conform to the ones previously observed for tench juveniles and indicate that the 1% b.w.d(-1) ration level (below satiation) could be advantageous for tench sub-adults as well.