Fatty acid composition and analysis of freshwater caridean shrimp Macrobrachium nipponense (De Haan) during spermiogenesis: Fatty acid composition of M. nipponens

We analysed fatty acids (FAs) composition and the potential functions of FAs in hepatopancreas and testis of freshwater caridean shrimp Macrobrachium nipponense during testis development. The hepatopancreas presented a high unsaturated FA content of about 40%, whereas the testis showed a high level of saturated fatty acids (SFAs) with a decreasing content of 97-86% of total FAs during maturation. Several specific FAs in testis showed significant changes throughout maturation. Among SFAs, C14:0 contributed with a relatively constant high proportion of about 22%, whereas C16:0 and C18:0 contents were also at high levels but showed significant increases during maturation. Representatives of highly unsaturated fatty acids (HUFAs), such as C18:1n-9, C18:2n-6, C20:5n-3 (EPA), C20:4n-6 (AA) and C22:6n-3 (DHA) showed significant increases despite their low proportion in the gonad. These results suggest that a high content of HUFAs in hepatopancreas may represent a reservoir for sperm production. The FA C14:0 may provide a particular function. The variations of the FA profile in testis at different developmental stages reveals that C18:1n-9, C18:2n-6, C20:5n-3, C20:4n-6 and C22:6n-3 may play important roles in spermiogenesis.