The response to a novel prey item was investigated during the first month of feeding of the cichlid fish Cichlasoma managuense. The relative contribution of size and age to improvement in predatory behavior was addressed. Group I (control) was fed nauplii of Artemia salina and group II a manufactured flakefood diet. Group II fish were tested for their ability to prey on a novel diet, the nauplii of Artemia salina. Latency to respond to the presence of novel prey decreased and the number of capture attempts increased with increasing experience with the artificial diet and with age. As size increased so did the number of capture attempts, but the latency did not change. Size and experiential and maturational factors may affect parts of the predatory behavior differentially. During the first month of feeding, age may be more important than size for the decrease in latency and the increase in the number of capture attempts. The number of capture attempts during the first 30 s of the observation period and the capture success increased faster than the latency decreased. Latency to respond to novel prey may mature at a slower rate than the number of capture attempts.