Reproductive performance in
male European sea bass (Dicentrarchus labrax, L.) fed two
PUFA-enriched experimental diets: a comparison with males fed a wet diet
J.F. Asturiano, L.A. Sorbera, M. Carrillo, S. Zanuy,
J. Ramos, J.C. Navarro, N. Bromage-2001
Aquaculture, 194 (1-2): 173-190
Abstract:
Reproductive performance of male European sea bass (Dicentrarchus
labrax) fed a wet diet (WD) was compared to that of fish fed two
commercial pelleted diet enriched with polyunsaturated fatty acids (PUFAs)
by the use of Northern hemisphere fish oil (ST) or tuna orbital oil (RO).
Broodstock growth, spermiation duration, milt production, milt spermatozoa
density, sperm motility, milt lipid composition, and fertilization rates
were compared during the reproductive season.
RO and ST males exhibited longer spermiation periods
producing statistically higher milt volumes and milt spermatozoa densities
as compared to WD; no differences in quality or motility of sperm were
observed between groups. Although the fertilization rates of RO, ST and WD
milt at 3 and 24 h after fertilization were similar (88--90%), significantly
higher rates of embryonic and larval survival were observed at 48 and 72 h
after fertilization from eggs fertilized with ST (13.9% and 15.5%) and RO
milt (20.9% and 20.6%) as compared to WD (1.0% and 1.2%). Analysis of milt
PUFA profiles revealed several differences between groups. Although total
PUFAs were increased in all groups as compared to diet PUFA composition, a
greater increase was noted for ST and RO. In January and March, fish fed the
WD exhibited more weight gain and attained significantly higher weights,
respectively, than RO fish. Results showed that although fish fed the WD
displayed increased weight gain, reproductive performance was enhanced in
males fed the commercially fabricated diets possibly reflecting benefits of
PUFA-enrichment.
(Instituto de Acuicultura
de Torre de la Sal (CSIC), Ribera de Cabanes, 12595 Torre de la Sal, Castellón,
Spain)