Reproductive Biology of African River Prawn Macrobrachium vollenhovenii (Crustacea, Palaemonidae) In the Lower Taylor Creek, Niger Delta, Nigeria

The sex ratio, Gonadosomatic Index (GSI) and fecundity of M. vollenhovenii in the Lower Taylor Creek, Niger Delta, Nigeria were studied between June 2008 and May 2010. The sex ratios showed that M. vollenhovenii deviated significantly from the ratio 1:1 and males dominated in M. vollenhovenii (X2 = 68.65, df = 1, P < 0.001). There were no monthly and seasonal variations in the GSI means (P > 0.05), even though there were peaks in September 2008 and January 2009. However, there were significant differences in the GSI values of the size classes (P < 0.05). The 8–9cm size class had the highest GSI value. The overall fecundity of M. vollenhovenii ranged from 11, 402 eggs (TL = 6.70cm) to 56,481 eggs (TL = 11.40cm) with a mean of 24,765±3144 eggs (P < 0.001). The correlations of fecundity–total length, fecundity–gonad weight and fecundity–body weight relationships of all the species were positive and gonad weight gave the best predictive values.