Effect of dietary
supplementation with shrimp on skin pigmentation and lipid composition of
red porgy (Pagrus pagrus) alevins
J.R. Cejas, E. Almansa, N. Tejera, S. Jerez, A. Bolaños,
A. Lorenzo-2003
Aquaculture, 218(1-4): 457-469
Abstract:
A feeding experiment was conducted on red porgy
alevins to investigate the influence of dietary supplementation with shrimp
on pigmentation and lipid composition of carcass (muscle and skin) and eyes.
To this purpose, red porgy alevins with an initial mean weight of 2.8±1.3 g
were divided into six groups. Three groups were fed gilthead seabream
commercial pellet (P, 100% pellet), whereas the other three were fed with
the commercial pellet and shrimp Pleisonika sp. (PS, 88% pellet:12%
shrimp) to provide the diet with a source of carotenoids. After 4 months of
feeding, the results showed that PS-fish groups displayed a pink-coloured
skin similar to that of the wild fish, whereas P-fish groups showed a
dark-grey-coloured skin. Furthermore, a higher total content of carotenoids
was found in carcass and eyes from PS-fish groups with respect to P-fish
groups. No significant differences in growth, survival or other gross
external signs were found between treatments. Total lipid (TL),
triacylglycerol (TG), phosphatidylcholine (PC) and phosphatidylethanolamine
(PE) of red porgy carcass exhibited a specific fatty acid profile. However,
the general patterns of the fatty acid distribution in lipids of carcass and
eyes from both groups of fish (P and PS) were similar, and only slight
differences were found mainly in carcass for some of the fatty acids. We
conclude that the natural carotenoids supplied by the shrimp were
effectively assimilated by the red porgy and allowed the cultured fish to
acquire a skin coloration similar to that of wild fish.
(Centro Oceanográfico de
Canarias (I.E.O.). Ctra. de San Andrés s/n, 38120 S/C de, Tenerife, Spain,
e-mail of A. Lorenzo: ealmansa@ull.es)