Male motility is suppressed by glycolytic inhibitors. The proportion of male gametes exhibiting each class of flagellar beat was determined in the presence of the glucose analogues 2-deoxy-D-glucose (not processed after phosphorylation by hexokinase) (A) and CM3361 (competitive inhibitor of glucose transport) (B) in the presence or absence of excess glucose (10 mM). (C, D) Patterns of motility were further categorized into fast beat, slow beat and immotile. (E) Values of flagella wave frequencies were measured with different concentrations of CM3361. Frequencies of waves were not altered by the presence of the inhibitor.