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Fatty acids in female ’s gonads of the Red Sea fish Rhabdosargus sarba during the spawning season
Authors: Suhaila Qari, Samia Moharram, Safaa Alowaidi
Number of views: 343
Objective: To determine the fatty acids profiles in female fish, Rhabdosargus sarba (R. sarba)
from the Red Sea during the spawning season.
Methods: Monthly individual R. sarba were obtained from Bangalah market in Jeddah, Red Sea
and transported to the laboratory in ice aquarium. The total length, standard length and weight
were measured, fishes were dissected. Ovaries were removed, weighed and 10 mL of concentrated
hydrochloric acid were added to 10 g of the ovary in a conical flask and immersed in boiling water
until the sample was dissolved and the fat was seen to collect on the surface. The conical was
cooled and the fat was extracted by shaking with 30 mL of diethyl ether. The extract was bowled
after allowing the layers to separate into a weighed flask. The extraction was repeated three times
more and distilled off the solvent then the fat dried at 100 °C, cooled and weighed. Then 50 mg of
lipid was put in a tube, 5 mL of methanolic sulphuric acid was added and 2 mL of benzene, the
tube well closed and placed in water bath at 90 °C for an hour and a half. After cooling, 8 mL water
and 5 mL petroleum were added and shaked strongly and the ethereal layer was separated in a
dry tube, evaporated to dryness. The fatty acid methyl esters were analyzed by using a Hewlett
Packard (HP 6890) chromatography, a split/splitless injector and flame ionization detector.
Results: In female R. sarba, a total of 29 fatty acids were detected in ovaries throughout the
spawning season. The main fatty acid group in total lipid was saturated fatty acid (SFA, 28.9%),
followed by 23.5% of polyunsaturated fatty acids (PUFA) and 12.9% of monounsaturated fatty acids
(MUFA). The dominant SFA were palmitic and stearic, the major MUFA were palmitoleic and oleic,
and the major PUFA were C18:2 and C22:2. During spawning stages, there were no significant
differences in total SFA, MUFA and PUFA. The highest value of SFA was in late spawning (36.78%).
However, the highest value of MUFA and PUFA was in spawning (16.70% and 24.96% respectively).
During spawning season there were significant differences in total SFA between March (late
spawning stage) and December (nearly ripe stage), P<0.05.
Conclusions: From the present study it has been shown that 29 fatty acids were detected in
ovaries of R. sarba throughout the spawning season. The main fatty acid group in total lipid was
SFA followed by PUFA and MUFA. The dominant SFA were palmitic and stearic, the major MUFA
were palmitoleic and oleic, and the major PUFA were C18:2 and C22:2. The highest value of SFA
was in late spawning. However, the highest value of MUFA and PUFA was in spawning.