Selective breeding for improved trait performance is a promising approach for developing new species for food production. Globally, a shortage of livestock species presents a significant bottleneck, and this is particularly pronounced for the aquaculture sector. In New Zealand, the Australasian snapper (Chrysophrys auratus) is a potential candidate for aquaculture, and a breeding programme was started in 2004. Here we assess the performance of the most recent F4 cohort in terms of growth and survival against 1) previous generations and 2) unselected offspring from wild broodstock over the first 6 months. First, we detected generational gains over the entirety of the breeding programme in growth, averaging 11.4% for length and 81.1% for weight over 3 years, and detected a strong seasonal Specific Growth Rate (SGR) increase during summer and a general decrease of growth with age. Second, when growing the F4 and F1 cohort side by side, we found a consistent pattern of superior performance, less growth heterogeneity, and a higher condition factor within the F4 population. Notably, these data revealed breeding gains of 4.9% in survival, 10.5% in length and 41.4% in weight for F4 snapper over the first 6 months from hatching. Together these results indicate that domestication gains and genetic improvement can strengthen the potential of snapper as a candidate to diversify and grow aquaculture in New Zealand.