Evaluation of the variability in proximate composition of Macrobrachium nipponense during spawning season

The variability in proximate composition of Macrobrachium nipponense (protein, fat, moisture and ash) and effects of sexual maturity on their values were examined. The study was conducted in July through September 2012 coinciding with spawning season of the species. Some 155 specimens of mature M. nipponense were collected randomly from a small stream in Jirdeh village- Guilan province and transferred to the laboratory of Aquatic Biology of the Department of Fishery- University of Guilan. In the laboratory the flesh of raw shrimps was separated from exoskeleton and used for evaluation of protein, fatty acid profiles, moisture and ash based on dry matter chemical analyses. The results of chemical analyses in July, August and September were 57.13± 0.007, 55.42± 0.014 and 53.42± 0.021 for protein, 4.41± 0.09, 3.6± 0.38 and 2.58± 0.24 for lipid, 75.75± 0.35, 77.4± 0.56 and 80.4± 0.75 for moisture and 7.34± 0.007, 7.28± 0.021 and 7.28± 0.021 for ash contents respectively. Analysis of the proximate composition of flesh showed a statistically significant decline (P