The early life stages of California yellowtail (Seriola dorsalis) and white seabass (Atractoscion nobilis) respond to food particle taste

Abstract One of the key limitations in the use of artificial microdiets for the culture of marine fish larvae and post-larvae is their poor acceptability. The chemosensory systems of adult and juvenile fish are known to serve important roles in the detection and selection of food items; however, the relative importance and functionality of chemosensory detection and responses are less well understood for the larval stages. Many chemical compounds previously found to promote feeding in fish are low molecular weight, water-soluble compounds that are prone to rapid leaching from artificial microdiets. Particle taste, which requires retention of these low molecular weight water-soluble compounds, is difficult to manipulate in currently available larval diets. In the present study, we used liposomes embedded in alginate particles (alginate complex particles), that showed high retention of low-molecular weight water-soluble compounds, as a tool to evaluate the impacts of several water-soluble organic compounds on the feeding of California yellowtail (Seriola dorsalis) and white seabass (Atractoscion nobilis). We also compared the relative importance of including (and retaining) these compounds within the particles (enhanced taste) as opposed to dissolving these compounds in the culture water (enhanced smell). The results of this study showed that alginate complex particles retained >50% of sodium fluorescein and >70% of amino acids after 1 h suspension in seawater. Moreover, we found that feed consumption rates (feeding incidence and fullness) were greatest when a mixture of glycine, betaine and alanine were included in the complex particles suggesting that particle taste was an important factor for influencing the feeding of white seabass and California yellowtail post-larvae.