Early larval nutrition remains one of the primary bottlenecks in marine finfish aquaculture. As part of the National Sea Grant Aquaculture Program project, Nutritional strategies for improved larval production of marine finfish with an emphasis on Seriola sp., we have conducted a series of complementary trials to address key gaps in diet formulation and delivery.
Recent experiments conducted at Hubbs-SeaWorld Research Institute compared several leading commercial microdiets with an open-formula reference diet (OFRD), developed to serve as a transparent benchmark for larval nutrition research. Results demonstrated that growth and survival of Seriola dorsalis larvae fed the OFRD were comparable to those fed the highest-performing commercial diets, confirming its value as both a research tool and an industry-relevant option. These results were confirmed by means of a feeding trial conducted by commercial partners (Kingfish Zealand) using Seriola lalandi as a test species.
Parallel work evaluated protein-coated microparticulate diets (PCMDs) developed to reduce leaching of water-soluble nutrients, a major limitation of current microdiets. The coatings improved particle stability and nutrient retention, and feeding trials showed that Seriola dorsalis readily ingested the particles and exhibited growth comparable to, if not slightly greater than, that of control groups (differences not statistically significant). Notably, one trial also demonstrated improved survival in the coated diet treatment. These findings suggest that the protective coating did not compromise digestibility or palatability, while potentially offering additional benefits for larval performance, thereby supporting PCMDs as a promising diet technology to enhance nutrient delivery during this critical life stage.
Together, these efforts represent meaningful progress toward the development of robust and open-formula larval diets for early-stage marine finfish. Outcomes will help reduce reliance on live feeds, improve survival and robustness of juveniles, and ultimately support the sustainable expansion of U.S. and global marine aquaculture.