علوم زیستی دریا
gh a; v y; v m
Abstract
In this study, the capacity of Siberian sturgeon, Acipenser baerii with mean weight 19.3±0.4 g to face short-term starvation and subsequent re-feeding was assessed for a 40-day period. To investigate, the effect of compensatory growth on some physiological response (plasma cortisol, thyroid hormones, ...
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In this study, the capacity of Siberian sturgeon, Acipenser baerii with mean weight 19.3±0.4 g to face short-term starvation and subsequent re-feeding was assessed for a 40-day period. To investigate, the effect of compensatory growth on some physiological response (plasma cortisol, thyroid hormones, glucose, protein, cholesterol and triglyceride) and morphological (total body weight and length, condition factor, hepato-somatic index, vicero-somatic index and digestive-somatic index) in Siberian sturgeon four different feeding regimes were established. Control group fed four times daily to apparent satiation; SRF1: 2 days starvation and 8 days refeeding; SRF2: 4 days starvation and 16 days refeeding; SRF3: 8 days starvation and 32 days refeeding were experienced. At the end of experiment, blood samples were collected to analyze biochemical parameters. Plasma cortisol and thyroxin (T4) hormones levels were not significantly different between control and food deprived groups at the end of experiment (P>0.05) but plasma tri-iodothyronin (T3) levels were lower in the starved groups compared to control animals, but this decreases only in S1 group was significant (P<0.05). There were no significant difference in measured metabolites levels between control and food deprived groups (P>0.05). Moreover, at the measured morphometric indices were not observed significantly different between the control and starved groups (P>0.05). The results suggest that Siberian sturgeon has the physiologic and metabolic adjustment ability to short-term starvation and return to basal level after re-feeding.
Esmaeil Hosseinnia; Ghobad Azari Takami; Ayoub Yousefi Jourdehi; Mahmoud Bahmani
Abstract
In this study, 4 different food diets were examined for feeding white worm which were studied. Results showed that suitable moisture for growth and development of white worm was 50 - 70 % that their biomass reached to a 675 g/m2 during 90 days. But it decreased significantly at moisture lower than 45 ...
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In this study, 4 different food diets were examined for feeding white worm which were studied. Results showed that suitable moisture for growth and development of white worm was 50 - 70 % that their biomass reached to a 675 g/m2 during 90 days. But it decreased significantly at moisture lower than 45 % and upper than 65 %. White worm had similar growth both in acidic and basic area. White worm biomass reached to 576g/m2 during 90 days in basic area but reached to 568 g/m2 in acidic that was maximum at pH 6.4 - 7.6, while its growth decreases at pH lower than 6 and higher than 8. In this study, Azola used as food for white worm in amount of 60%, wheat meal 25%, and wheat bran 15% that caused to more growth in worms and their biomass reached to 533 g/m2 during 90 days. Although biomass of worm fed with mixture of potato 30%, carrot 3%, wheat meal 25% and wheat bran 15% reached to 584 g/m2 , but biomass of worms were fed with mixture of potato 60%, wheat meal 25%, and wheat bran 15% reached to 576 during 90 days. Economically, cost production of Azola was lower in comparison to other diets. Biochemical decomposition of worms fed with mixture of Azola, wheat meal and wheat bran showed more protein (33 %) than others. Based on results Azola can be used as a suitable and commercial replacement for white worm food diets.