Publication Date:
2021-05-19
Description:
Acipenser persicus, one of the native Species living in the southern part of the Caspian Sea, has high Percentage of larval mortality. Therefor to decrease the rate of mortality of larvae survival and to increase to regenerate properly during the active feeding process of fish larvae, while under artificial reproduction they were fed withe fresh water rotifer. Four types of feeding treatments were applied as follow :Treatment 1: Similar to normal process , first withe Artemia cyst then withe Daphnia Treatment 2: Mixture of Artemia, Rotifer and Daphnia; Treatment 3 freshwater Rotifera ;Treatment 4: fresh water Rotifer enriched with Vitamin C (Ascorbic acid- 6- Palmytat ).Three replicates were used for each treatment. In the process of each observation 45 larvae in containers withe 100 liter capacity filled with 30 liters of water , after 8 days of external feeding process, were inspected closely, during which , they were under biometric measurement once every two days. Larvae were fed Four times a day at a rate of 25 % of their body weight. The average temperature estimation was 22/5 ±0/5 centigrade, pH of water being 8/5 ± 0/1 while Oxygen proved to be 9/58 ± 0/2 mg/l . At the end of the observation, the profill fatty acids of the remains were studied .The growth factors, the mouth size of the larvae and the expansion of the mouth size compared to the total length of the larvae during the whole observation were inspected. Credibility of data designated was examined by Shapiro Wilks test. Specific growth rate (SGR), weight growth (WG) and feed conversion ratio (FCR) were contemplated by one- way analysis test, and significant difference Tukey's test. The most notable diversity was evident between treatment 2 , whose indicative factors were in the following order : 4/ 65 ± 0/06, 45/18 ± 0/66, 4/48 ± 0/07 and treatment 4 whose indicative factors showed the following results: 10/47 ± 0/04, 124/42 ± 0/62, 1/51 ± 0/008.For the determination of fatness rate and weight gains, Kruskal Valis and Man vit ni test were used .In this part of study , the highest diversity fatness appeared to be between treatment 4 ,reflecting 0/79±0/07 and treatment 2 showing the result 0/62±0/05.The highest gain was related to treatment 4, whit the rate of 99/33 ± 0/68 mgr and the lowest gain occurred in treatment 2 white the rate 62/36 ± 0/65 mgr . This study also revealed that, the survival ratio connected with treatments 3 and 4 , compared treatments 1 and 2, were significantly different. The profile of fatty acids also showed much higher percentage of PUFA and HUFA in treatments 3 and 4 , than those in other treatments. Furthermore Brachionus calyciflorus proved to be a proper food supply for larvae. Therefore by building suitable pools next to the work side, other kinds of species fresh water rotifer could also be used as food improvements for feeding larvae.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Brachionus calyciflorus
;
Acipenser persicus
;
Fatty acid
;
Larvae culture
;
Vitamin C
;
Larval survival
;
Species
;
Mortality
;
Feeding
;
Artemia
;
Cyst
;
Ascorbic acid
;
Oxygen
;
Growth
;
SGR
;
FCR
;
Fresh water
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
78pp.
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