Three frozen mono-diets (sardine, crab and squid) were supplied to Octopus vulgaris broodstocks, and their effects on the spawn quality and biochemical composition of eggs and hatchlings were studied. Squid and crab diets achieved superior spawn quality, producing in general significantly larger eggs, as compared to sardine diet. Similar differences were also observed in the biometrics parameters of hatchlings (ventral and dorsal mantle lengths and dry weight) as well as in the survival of fasted hatchling which were greater in the squid and crab groups respect to sardine treatment. On the other side, a strong and significant relationship between the mentioned biometrical measures and hatchlings survival was found, suggesting that eggs and hatchlings early biometrical measures can be utilized as a predictor for larval viability.