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Abstract
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Background. Fish may experience periods of food deprivation or starvation in nature and under culture conditions.
Because of the wild stock reduction of some sturgeon species, Siberian sturgeon, Acipenser baerii Brandt, 1869, has
been used as a biological model of physiological and nutritional studies since the 1980s. There are no published
records on the physiological responses of Siberian sturgeon to starvation. Hence, in this study the effect of shortterm
starvation (0, 2, 4, and 8 days) on plasma thyroid hormones (T3 and T4), total protein levels, and hepatosomatic-
(HSI), viscero-somatic- (VSI), and digestive-somatic (DSI) indices in juvenile Siberian sturgeon was
investigated.
Materials and methods. The experiment was conducted at the International Sturgeon Research Institute of Rasht
(Iran) in October 2009, using a semi-natural environment (natural photoperiod and natural water temperature
fluctuations). After a period of adaptation (10 days on a formulated diet), 180 juvenile Siberian sturgeon individuals
(mean weight ± standard error at start of experiment: 19.32 ± 0.43, n = 15) were randomly distributed among
twelve circular, 500-L, fibreglass tanks with a flow-through system. In this trial, control (C) was fed a formulated
diet to apparent satiation four times daily throughout the experiment. The other three groups were deprived of
feed for 2- (2S), 4- (4S), and 8 (8S) days, respectively. At the end of the starvation periods, blood samples were
collected to analyze biochemical and physiological parameters.
Results. Plasma T3, T4, and total protein levels did not significantly vary between the fed and the starved fish.
In comparison to the starved groups, after 8 days of starvation, plasma total protein in group 8S (3.43 ± 0.20) was
markedly higher than in 2S (2.67 ± 0.07) and 4S (2.37 ± 0.12) groups. In the presently reported study, a decrease
in the measured morphometric indices was observed with an increase in the length of the starvation period.
Conclu
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