Annual variation and relationship between the gonadosomatic index (lG) and the condition index (K) of Holacanthus passer were evaluated in 194 specimens from Cueva de León, Gulf of California (24°02' N, 110º 24' W). There was a significant negative correlation between IG and K in both sexes: indices exhibit an oposite seasonal pattern. The reproductive activity of both sexes is inversely related with nutritional status. There was a significant difference in IG but not in K values between males and females. The condition index may be used to determine reproduction time of the species in other localities without sacrificing the organisms. This could be a valuable tool to develop monitoring programs for fisheries and culture of this species

Holacanthus passer ; Pomacanthidae; gonadosomatic index; condition index; Gulf of California; Mexico