The relationship between
individual consumption and growth in juvenile turbot, Scophthalmus
maximus
S. Irwin, J. O'Halloran, R.D. FitzGerald-2002
Aquaculture, 204(1-2): 65-74
Abstract:
The development of feeding hierarchies was
investigated in juvenile turbot, Scophthalmus maximus (Rafinesque)
held at two rearing densities for 82 days. Individual biometrics were
measured on five occasions and a diet labelled with ballotini glass beads
was used in combination with a noninvasive radiographic technique to
estimate consumption rates. The results demonstrate that the inclusion of
the radio-opaque glass beads in the diet did not significantly reduce
consumption by turbot. A significant relationship was found between
individual consumption and growth of juvenile turbot. A weight differential
within groups increased with time and was largely explained by
inter-individual variation in food consumption. This differential was driven
by an uneven distribution of food within groups, where individuals of a
higher weight than the group average consistently consumed a greater than
average share of the group meal, and showed less day to day variation in
consumption than their smaller counterparts. The results demonstrate that in
captive turbot groups, size hierarchies are mediated, at least in part,
through inter-individual differences in food consumption.
(Aquaculture Development Centre, Department of
Zoology and Animal Ecology, University College Cork, National University of
Ireland, Cork, Ireland, Tel.:
+353-21-4904053; fax: +353-21-4277922, e-mail: s.irwin@ucc.ie)