Preprint volume - SIBM

Pre-print Volume – Posters
AQUACULTURE COMMITEE
G. CARUSO, G. MARICCHIOLO, U. MUGLIA 1 , L. GENOVESE, M.G. DENARO 2
Institute for Coastal Marine Environment (IAMC), CNR, Spianata S. Raineri, 86 – 98122 Messina, Italia.
gabriella.caruso@iamc.cnr.it
1 Department of Morphology, Biochemistry, Physiology and Animal Production, University of Messina, Italia.
2 Department of Life Sciences “M. Malpighi”, University of Messina, Italia.
CHANGES IN SOME PHYSIOLOGICAL PARAMETERS OF RED PORGY
PAGRUS PAGRUS DURING A FASTING-REFEEDING EXPERIMENT
VARIAZIONI DEI PARAMETRI FISIOLOGICI IN PAGRUS PAGRUS
SOTTOPOSTO A DIGIUNO E RIALIMENTAZIONE
Abstract – A fasting-refeeding experiment was carried out in red porgy, Pagrus pagrus (Teleostei, Sparidae)
to assess the effect of a 21 day- starvation period on some physiological parameters. Both haematological
and biochemical parameters and digestive enzyme patterns were considered. Results showed that starvation
resulted in a general, although not significant, decrease of digestive enzyme levels, with a recovery to
initial values after refeeding. No significant changes were observed in both haematological and
biochemical parameters.
Key-words: starvation, stress, enzymes, Pagrus pagrus.
Introduction – Red porgy is a promising species for aquaculture diversification. It is
known that unbalanced feeding or starvation can result in a stress condition, so the
study of physiological responses to starvation in farmed species is interesting to
develop proper management practices (Caruso et al., 2008). Different aspects of the
physiology of red porgy are unexplored especially those related to stress and digestive
physiology. This study aimed at investigating the physiological responses of red porgy
to a short starvation period, followed by re-feeding. The conventional stress indicators
(cortisol, glucose and haematocrit) and digestive enzymes were monitored up to 15
days after re-feeding, in order to evaluate the possible recovery of the physiological
parameters to the pre-fasting levels.
Materials and methods – Adult red porgy (n=30) (mean weight: 366.0±36.1 g) were
obtained by a Sicilian fish farm and kept at the IAMC aquaculture plant. After
acclimation (21 days), fish were divided into two groups, one of which was kept
starved while the other was fed “ad libitum” with commercial feed. At T0 and T1
(before and 10 days after starvation, respectively) three fish from each group were
collected after euthanasia in a lethal dose of MS-222. The starved group was further refed
up to 20 days; during this period, two other samplings were performed, 7 and 15
days after re-feeding (T2 and T3, respectively). At each sampling, blood was drawn
from the caudal vein for the determination of serum cortisol and glucose by
commercial kits based on ELISA immunoassay and enzymatic colorimetric method
(GOD-POD), respectively; the haematocrit was determined by a microcentrifugation
method. Enzyme activities (total proteases, pepsin, trypsin, chymotrypsin,
carboxypeptidases A and B, amylase, lipase) were measured along the digestive tract
(stomach, proximal gut, midgut and distal gut), excepting the stomach for lipase only
(Caruso et al., 2009). Enzyme values were reported as specific enzyme activities
(U/mg protein). All data were analysed by Student’ t test.
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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