Due to the significant growth benefits, triploid technolog y has become increasingly common in oyster aquaculture accounting for the vast majority of farm-raised oysters in many regions. Although triploids are very common in aquaculture, regions such as Long Island NY have been slower to adopt and implement the technology with anecdotal reports from baymen claiming that the triploids they have previously grown were “frail” or “ugly”. The reason for such reports is unknown and may be due to the triploids used originating from distant locations and not optimized for local stressors, diminishing the benefits of the technology. To address this, 9 oyster lines were produced and evaluated, consisting of 3 purebred local diploid lines, 3 hybrid triploid lines (local lines crossed with NEH tetraploids), and 3 hybrid diploid lines (local lines crossed with NEH diploids). Larvae and juvenile resistance to experimental exposure to Vibrio pathogens was assessed. Field grow-out experiments were also conducted in 5 separate locations to compare seed growth and survival up to market size . When exposed to Vibrio pathogens, larval and juvenile diploids outperformed triploids by 53% and 17% respectively, with no significant difference based on parental genotype. In the field, overall triploid growth was 30% greater compared to diploids. No significant difference was observed in survival when comparing ploidy alone, however significant differences were observed between locations and maternal genotypes . Differences in ploidy survival appear to be most pronounced during early developmental stages but become more dependent on genotype-location interactions as oysters mature.