siamese fighting fish losing colourThe agonistic interactions ordinary of paired male conspecifics are energetically costly, as indicated by associated raises in whole animal metabolic rate. However, little is thought in regards to the biochemical responses that underlie metabolism and function during agonistic encounters. We tested biochemical indices of cardio and anaerobic energy metabolism in locomotory muscle to confirm even if they’re important correlates of aggressive behavior. Pairs of male B. splendens were allowed to interact aggressively across a glass partition while their behaviors were quantified astonishing, opercular flaring, surfacing for air and the levels of a few key metabolites including lactate, creatine phosphate, free creatine, adenosine triphosphate, free adenosine diphosphate and activities of enzymes of cardio citrate synthase and anaerobic pyruvate kinase, lactate dehydrogenase metabolism were assayed in their muscle at the tip of the trial. More aggressive fish those showing a far better strike frequency had higher surfacing frequencies possibly to access aerial oxygen, as well as higher cardio capacities as indicated by citrate synthase recreation, higher levels of lactate and lower levels of creatine phosphate in the muscle at the end of an stumble upon.