Some Age Related Attributes of Macrobrachium mcrobrachion (Herklots, 1851) from Luubara Creek in Ogoni Land, Niger Delta, Nigeria

S. N. Deekae ； J. F. N. Abowei

《Current Research Journal of Biological Sciences》 2卷5期 (2010/09) Pp. 313-322

並列摘要

Some Age related attributes of Macrobrachium mcrobrachion from Luubara Creek in Ogoni Land, Niger Delta, Nigeria was studied for a period of two years (January 2006 - December, 2007). The age composition of the shrimps estimated from the length-at-age data obtained from Paul’s integrated plots based on the carapace length showed that; in 2006 males of one year plus represented 35.63% of the sample population while two years plus constituted 55.17% of the sample population. Shrimps of three year plus constituted 6.89% of the sample population while of four years plus represented only 2.29% of the sample population. Shrimps less than one year were not observed. In 2007, male shrimps less than one year of age constituted 32.09% of the sample population while those of one year plus constituted 44.44% or the majority of the catch. Shrimps aged two years plus were 16.04% of the sample population and those of three years plus were 7.40% of the sample population. There were no shrimps of more than four years during the study in 2007. In 2006, there were no female shrimps below one year. Shrimps of one year plus constituted 24.77% of the sample population; shrimps of two years plus constituted 62.83% of the sample population while shrimps of three years plus constituted 12.38% of the population. There w ere no female shrimps of above four years in 2006. In 2007, there were also no shrimps above four years. Female shrimps of one year plus was 31.11% of the sample population while those more than two years were 54.54% of the sample population. Female shrimps of three years plus constituted only 14.28% of the sample population in 2007. In the berried female shrimps, no shrimp was recorded below one year of age in 2006. Berried female shrimp within one year plus constituted 60% of the sample population while those of two years plus constituted 40% of the sample population. Shrimps of three years age were not found. In 2007, no berried females shrimps caught were below one year. Shrimps of two years plus constituted 70% of the sample population. The relative ages and modal lengths (i.e., length - at - age) of M. macrobrachion obtained through Pauly’s Integrated distribution plots are showed that the ages attained in males ranged from +1 year to 4 years while the female attained a maximum age of 3 years. It was observed that the growth in length was faster in the males than in females. The annual increment of males was between 3-10 mm in 2006, while berried females had between 3-6.5 mm annual increments. Individual growth also decreased according to age. Individual grow ths between two age groups were considerably low.

並列關鍵字

Age ； Macrobrachium mcrobrachion ； Luubara C reek ； Ogoni Land ； Niger Delta ； Nigeria