Fatty acid composition of two candidate species of aquaculture, Fenneropenaeus merguiensis and F. penicillatus (Crustacea: Decapoda) in Pakistan.

Fatty acid composition was determined in two candidate aquaculture species Fenneropenaeus merguiensis and F. penicillatus sampled from Karachi, Pakistan. Five fatty acids, that is, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), oleic acid (18:1n-9), palmitic acid (16:0) and stearic acid (18:0) were particularly abundant in the muscle tissues of both species. Palmitic acid and oleic acid were the most abundant saturated and monounsaturated fatty acids, respectively in F. merguiensis and F. penicillatus. Among PUFA, the predominant fatty acid were docosahexaenoic acid (DHA; 22:6n-3), eicosapentaenoic acid (EPA; 20:5n-3) and arachidonic acid (ARA; 20:4n-6). No significant differences were observed in the contents of total saturated, monounsaturated and polyunsaturated fatty acids among two species. The n-3/n-6 fatty acid ratios, DHA/EPA ratios and ARA/EPA ratios were similar in two species. Fatty acid profiles have been reported to show seasonal changes in penaeid shrimps, thus there is a need to study the fatty acid composition of F. merguiensis and F. penicillatus in various seasons as the present study was conducted in spring only.