The feeding behaviour of medium sized (155.25 +/- 27.98 cm, n = 8) whi
ting, Merlangius merlangus, under laboratory conditions was investigat
ed with continuous food availability. This investigation was made usin
g both natural, Sprattus sprattus, and artificial diet which was monit
ored with a periodogram analysis obtained by a newly developed demand
feeding unit. The return of appetite of large whiting (305.85 +/- 056.
90 cm) was also studied. Medium size whiting consumed 5.29 g (wet weig
ht)/day corresponding to 3.41% body weight, approximately three sprats
of 1.88 g each. The return of appetite after a single meal was found
to follow the gastric emptying curve closely. If food is not offered d
irectly but made available through demand feeding, the whiting feed rh
ythmically (every 21 h); under these conditions, it was estimated that
feeding activity returns when the stomach is 40% full. (C) 1998 Elsev
ier Science B.V.