Speakers - AFHWC2025

Abstract

The population of shrimps, especially the Macrobrachium genus, has been affected with habitat pollution and overexploitation. Shrimps provide a major protein source to animals higher in the food chain. The importance of studying reproduction parameters of Macrobrachium dux in the Lepmassoun river help in their preservation and provides possibilities of freshwater farming.  M. dux were sampled using the scoop method with hand nets. Sampling was done in 5 seasons distributed from January 2017 to February 2018. In Lepmassoun a total of 5 individuals were collected with the male-female ratio was 0.25. Three females were ovigerous, the absolute fecondity ranged from 39 eggs (size = 50.38 mm, weight =1.76g) to 100 eggs (size = 64.18mm, weight = 2.96g) and relative fecundity ranges from 22.18 (GSS) to 33.69 (PSS), thus the largest the female of M. dux, the more prolific she is in Lepmassoun.  The egg size varied from 1.7 to 2 mm and there was of stage II of maturity (light brown). The ratio gonado-somatic (RGS) varied from 4. 44% for the female collected to the big dry season (GSS) to 12.35% for the female collected during the small dry season (PSS), the mean RGS was 9.11%). The fluctuation in the number and percentage of ovigerous females indicated that the prawn spawned twice year during the big and small dry season. The ovigerous females  collected during the small dry season had a more advanced state egg maturity compared than the female collected during the GSS (RGS=12,35%). 

Keywords: Macrobrachium dux, growth pattern, reproductive period, fecundity, basin Nyong, Cameroon.