The Mortality, Exploitation Rate and Longevity of Macrobrachium macrobrachion (Herklots, 1851) in Luubara Creek, Ogoni Land, Niger Delta, Nigeria

The mortality, exploitation rate and longevity of Macrobrachium macrobrachion from Luubara in Ogoni land area of N iger Delta, Nigeria was studied for period of two years (January, 2006 - Decem ber, 2007). Total mortality (Z) estimated for 2006 was 2.60 per year and for 2007 2.80 per year. The estimated average total mortality (Z) for M. macrobrachion in Luubara creek was 2.75 per year. The natural mortality was 2.04 per year while the fishing mortality was 0.72 per year. Exploitation rate for M. macrobrachion in Luubara creek was 0.24 in 2006 while in 2007 it was 0.27 with a mean of 0.25. Male shrimps attained sexual maturity between 11mm and 14 mm carapace length at one year plus while female shrimps reach sexual maturity between 8 mm and 25 mm carapace length and a mean length of 11.2 mm. The longevity estimated for M. macrobrachion in Luubara creek was 1.51 years. This shows that it is a short lived species like other shrimps. In both years, M. macrobrachion in Luubara Creek was under exploited. Therefore, there is the urgent need to improve its fishery.