Publication Date:
2021-05-19
Description:
In this study, Daphnia longispina were fed with two freshwater green algae species, Chlorella vulgaris and
Scenedesmus dimorphus, enriched with Docosahexaenoic acid (DHA). Chlorella vulgaris and Scenedesmus
dimorphus were isolated and cultured for mass production. Three treatments with three replicates and a control
group were considered to conduct this study. In order to investigate feeding, a total of 30 Acipenser persicus
larvae with the initial mean weight of 68±3.6 mg were distributed into 12 plastic tanks of 60 L. Experimental
fish larvae were fed daphnia collected from earthen ponds (as control group), daphnia enriched with
Scenedesmus dimorphus (treatment 1), daphnia enriched with Chlorella vulgaris (treatment 2) and daphnia
enriched with Chlorella vulgaris and Scenedesmus dimorphus (at the rates of 50%) (treatment 3). The
microalgae density to enrich daphnia is estimated at 5×107
cells mL-1
. Fish larvae were fed at an amount of 30%
body weight per day for four times. During the experimental period, water temperature, dissolved oxygen
concentration and pH ranged between 18-24°C, 5.8-7.2 mg l-1 and 5.6-8.2, respectively. Monounsaturated fatty
acids (MUFA) were the highest (32.3 %) in D. longispina enriched with Chlorella vulgaris and the highest
concentration of polyunsaturated fatty acids (PUFA) (19.8%) was observed in D. longispina enriched with
Scenedesmus dimorphus. The highest (21.6%) and lowest (13.2%) concentrations of PUFA in fish larvae were
recorded in treatment 3 and the control group, respectively. The results obtained from the body weight increase
(BWI %) revealed that there were significant differences (P≤0.05) between treatment 3 (daphnia enriched with
chlorella and scenedesmus) and other treatments. The highest (5.5 ± 1.24 % day-1) and the lowest (4.6± 1.13%
day-1) mean specific growth rates (SGR) were recorded in fish fed treatment 3 and the control group,
respectively. The lowest (68%) and the highest (85%) survival rates were obtained in the control group and
treatment 3, respectively.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Daphnia
;
Daphnia longispina
;
Chlorella vulgaris
;
Scenedesmus dimorphus
;
Enrichment
;
Microalgae
;
Acipenser persicus
;
survival
;
Larvae
;
Phytoplankton
;
PUFA
;
Growth
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
41pp.
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