Can turbot, Psetta maxima, be fed with self-feeders?

The capability of turbots to use self-feeders was studied using 3 groups of 100 juveniles. Feeding activity reached a plateau after 20 days. Almost all feeding activity was observed during the photophase, and the acrophase was associated with dawn. The proportion of nocturnal demands was the highest in the replicate with the lowest feed efficiency, suggesting that feed waste was mainly occurring during nocturnal feeding activity. During the last 30 days of the experiment, demands were only rewarded during two periods of 2.5 h.day(-1). Feed efficiency was improved and was homogeneous between the three tanks, but the voluntary feed intake was reduced. It is concluded that turbots are able to use self-feeders but they do not adapt quickly, and they are not able to compensate a reduction of feed access by increasing demand activity during the access period.