Abstract

The early life stages of merobenthic octopus paralarvae, such as Enteroctopus megalocyathus (Patagonian red octopus), rely on live feeds and have demonstrated improved growth and survival when fed mixtures of various prey. However, transitioning from live food to formulated diets is a key step to sustainable production. This study aimed to evaluate the impact of partially replaced live food with a formulated moist diet (FMD) on performance in early E. megalocyathus paralarvae. Thus, 900 paralarvae were randomly assigned to 12 20-L tanks to evaluate two dietary treatments: one with 100% mixed-food Artemia and juvenile crabs Petrolisthes laevigatus (AC), and another with 80% AC plus 20% FMD. The FMD was prepared by blending shrimp meat into a gelatin-based mixture and imbibing them into polystyrene multiwell microplates. After 15 days, no differences were observed in growth rates, enzyme digestive activities (trypsin, chymotrypsin, lipase, and leucine aminopeptidase), and SOD activity. Further, the gene expression of gpx, sod, cat, hsp70, fads, and elovl were comparable between paralarvae fed AC than those receiving the AC-FMD combination. However, the paralarvae fed AC-FMD exhibited lower GPX activity. These findings suggest that FMD is a good strategy to support digestive system maturation. Additionally, the retention of 20:1n-9, 20:4n-6, 20:5n-3, and 22:6n-3 in both dietary groups highlight the physiological demand for these fatty acids during early paralarvae development. The fact that moist diets were accepted by the paralarvae, despite no growth or survival was improved, suggests that further enhancements in paralarvae nutrition should be improved by optimizing the nutrient requirements.