Age, growth and reproduction of Marcusenius pongolensis, Oreochromis mossambicus and Schilbe intermedius in an oligotrophic impoundment in Swaziland

作者：Booth Anthony J^*; Khumalo Nokuthula

来源：African Journal of Ecology, 2010, 48(2): 481-489.

DOI：10.1111/j.1365-2028.2009.01136.x

• length at maturity
• Mnjoli Dam
• otoliths
• reproductive seasonality
• sex ratio
• Von Bertalanffy growth model

The age, growth and reproductive biology of Marcusenius pongolensis, Oreochromis mossambicus and Schilbe intermedius were investigated in the Mnjoli Dam, Swaziland. Otolith annulus formation occurred in winter for M. pongolensis, and in spring/summer for O. mossambicus and S. intermedius. Maximum ages of 8, 6 and 8 years were recorded for M. pongolensis, O. mossambicus and S. intermedius, respectively. Growth was described by the von Bertalanffy growth model as L(t) = 238.73(1 - exp-0.27(t 2.27) mm fork length (FL) for M. pongolensis, L(t) = 226.83(1 - exp-0.45(t 2.02)) mm total length (TL) for O. mossambicus, and L(t) = 214.59(1 - exp-0.60(t 1.20)) mm FL for S. intermedius. Sexual maturity was estimated for male and female M. pongolensis at 134 mm FL and 119 mm FL, respectively. Marcusenius pongolensis matured within their first year. Female O. mossambicus and S. intermedius matured at 239 mm TL and 205 mm FL, corresponding to 2 and 4 years of age, respectively. Extended spawning periods, with two spawning peaks was observed for M. pongolensis, one in spring (September) and the second in autumn (March) and one peak over late-summer for S. intermedius.

• 出版日期2010-6