Three different
lipid sources in formulated start-feeds for turbot (Scophthalmus maximus,
L.) larvae - effect on growth and mitochondrial alteration in enterocytes
R. MacQueen Leifson, J.M. Homme, ø.
Lie, R. Myklebust, T. Strøm-2003
Aquaculture
Nutrition, 9(1): 33-42
Abstract:
Turbot, Scophthalmus maximus,
larvae were start-fed with formulated feeds containing soya phospholipids
(SP), marine phospholipids (MP) or triacylglycerol (TAG). The levels of
eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were the same in
the MP and TAG feeds. The control group was given rotifers (R). The larvae
were offered feed from day 4 post-hatch. Larvae fed formulated feed with
added MP showed good initial growth and there were no significant
differences in weight on day 6 between this group and the group given
rotifers. Using feed with added TAG enriched with EPA and DHA gave no growth
at all. Using SP as the lipid source in the feed resulted in reduced initial
growth. Electron microscopical examination of enterocytes was performed on
larval intestines on day 6. Larvae fed MP, TAG or rotifers had normal
looking enterocytes with numerous normal looking mitochondria. In the
enterocytes of larvae fed SP the mitochondria appeared swollen with a
translucent matrix and fragmented cristae. Thus, SP or TAG appear not to be
suitable as the sole source of lipids and/or phospholipids in start-feed for
turbot larvae and the effects of MP are not solely caused by high levels of
EPA and DHA.
(Norwegian College of Fishery Science, Institute of
Marine Biotechnology, University of Tromsø, Breivika, Tromsø, Norway)