Length Frequency Distribution And Sex Ratio Of Macrobrachium Macrobrachion In The Lagos – Lekki Lagoon System, Nigeria

Abstract

Length frequency distribution and sex ratio of Macrobrachium macrobrachion sampled by cane traps in the Lagos –Lekki lagoon system were estimated from May 2002 to April 2004. The total number of size classes for the first and second year for both male and female ranged from 10 – 12. The length range was 3 to 14cm for the two sexes. Young adult category constituted the highest percentage of all the catches for both male and female for the two years. Female class size with the highest percentage was 7cm and 8cm for years 1 and 2 respectively, while for the male it was 8cm and 7cm for these two years respectively. The over all sex ratio for the entire sampling period was 1: 2, male to female. Length frequency distribution has shown that from the management view point for resource sustainability, there is need for caution since the majority of the catch is made up of young adults that may not have had the opportunity to reproduce.

Keywords: Length frequency distribution, Sex ratio, Macrobrachium macrobrachion
Lagos-Lekki Lagoon System.

The Zoologist Vol. 6 2008: pp. 16-20