Nutritional effects on male reproductive performance in the freshwater prawn Macrobrachium malcolmsonii (H. Milne Edwards)

The reproductive performance (spermatophore weight, sperm count, live and abnormal sperm percentage) of male freshwater prawns ( Macrobrachium malcolmsonii) was assessed at weekly intervals in prawns fed for 8 weeks on diets of clam meat, squid and pellet feed (experiment I), clam meat daily (experiment II) and clam meat once in every two days (experiment III). Good reproductive performance was observed when the animals were fed with a mixture of clam meat, squid and pelleted feed. In experiment I, relative spermatophore weight remained constant throughout the study period. However, in experiments II and III, spermatophore weight decreased by 71% and 43%, respectively, at the end of the study period. No significant reduction in sperm count and percentage of live sperm were observed in experiment I. However, both decreased significantly over the weeks in experiment II and III, with no significant difference between them. The relative sperm count was 101% in experiment I. It decreased to 0% in weeks 7 and 8 in experiment II and III, respectively. The percentage of abnormal sperm increased significantly in experiments II and III over successive weeks but not in experiment I. Thus, the male reproductive performance is affected by the nutritional status of the animals.