- 期刊
- OpenAccess
Some Population Parameters of Distichodus rostratus (Gunther, 1864) from the Fresh Water Reaches of Lower Nun River, Niger Delta, Nigeria
並列摘要
Some population parameters of Distichodus rostratus from the fresh Water reaches of lower Nun River in the Niger Delta area of Nigeria, was studied for a period of one year (January, 2008-December 2008), using five hundred specimens. The regression equation for the length weight relationship was Log W = 0.0136+2.76 logL and correlation coefficient w as 0.976 at p＜0.05. The regression equation for length breadth relationship was Log M=1.60 Log T(subscript L) and correlation coefficient was 0.968 at p＜0.05. The largest specimen measured 54.0 cm and weighed 442.8 g at age 5+. Growth increment in length (22.0 cm) was highest in 1-2 years; while growth in weight was highest (141.5 g) in 2-3 years. The Maximum length at age attained L(subscript max) was 54.0 cm weighing 420.8 g. The length attained at infinity (L∞) was 55.0 cm. Growth exponent (b) was 2.76. Length performance index (21) value was 2.87. Weight performance index value (Ø) was 1.48. Growth coefficient (K) value was 0.27. The hypothetical age at which length is zero (T0) was -0.46 and the maximum age estimated was 6 years. There was no temporal variation in the condition of the fish through out the year with condition index value ranging from 0.96-1.00 and condition factor value of 0.98. Total mortality (Z) value was 1.5 yr^(-1). Natural Mortality (M) value was 0.97; fishing mortality (F) value was 0.52. Value for the rate of exploitation was 0.35 with corresponding percentage value of 30. Distichodus rostratus populations from the fresh water reaches of the lower nun river was Lower than the optimal value for sustainable yield, for the exploitation of the fishery; therefore stands the risk of under exploitation if urgent measures are not taken to develop the fishery.
延伸閱讀
- Kingdom, T., & Allison, M. (2009). Aspects of the Reproductive Biology of Pellonula leonensis (Boulenger, 1916; Clupeidae) in the Lower Nun River, Niger Delta. Current Research Journal of Biological Sciences, 1(3), 68-71. https://www.airitilibrary.com/Article/Detail?DocID=20410778-200910-201009060065-201009060065-68-71
- Abowei, J. F. N. (2010). The Condition Factor, Length-Weight Relationship and Abundance of Elops seneganensis (Regan, 1909) from Nkoro River, Niger Delta, Nigeria. Advance Journal of Food Science and Technology, 2(1), 16-21. https://www.airitilibrary.com/Article/Detail?DocID=20424876-201001-201009060052-201009060052-16-21
- Abowei, J. F. N. (2009). The Abundance, Condition Factor and Length-weight Relationship of Cynoglossus senegalensis (Kaup, 1858) from Nkoro River Niger Delta, Nigeria. Advance Journal of Food Science and Technology, 1(1), 57-62. https://www.airitilibrary.com/Article/Detail?DocID=20424876-200912-201008160018-201008160018-57-62
- Abowei, J. F. N. (2009). The Morphology, Abundance, Condition Factor and Length-weight Relationship of Ethmalosa fimbriata (Bowdish 1825) from Nkoro River Niger Delta, Nigeria. Advance Journal of Food Science and Technology, 1(1), 51-56. https://www.airitilibrary.com/Article/Detail?DocID=20424876-200912-201008160018-201008160018-51-56
- Abowei, J., & Davies, O. (2009). Aspects of Sphyraena Barracuda (Wallbaum, 1992) Population Dynamics from the Fresh Water Reaches of Lower Nun River, Niger Delta, Nigeria. Current Research Journal of Biological Sciences, 1(1), 21-27. https://www.airitilibrary.com/Article/Detail?DocID=20410778-200907-201008160021-201008160021-21-27