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Taurine is an essential or conditionally essential nutrient for many species of marine fish, especially during early development. There is growing evidence that marine fish larvae benefit from taurine-enriched rotifers; however, it is unknown if larvae benefit from taurine-enriched Artemia. We investigated the effects of taurine-enriched rotifers (Brachionus plicatilis) and Artemia franciscana on the growth and wholebody taurine concentrations of California yellowtail (Seriola lalandi; CYT) larvae. The approach used in this study was to encapsulate taurine within microparticles (liposomes), which were then fed to rotifers and Artemia. We found that feeding taurine liposomes to rotifers and Artemia resulted in taurine concentrations in these prey species that were similar to or above those previously reported in copepods. At the end of the rotifer phase, CYT larvae fed taurine-enriched rotifers showed increased growth (final dry weights; DW) and had higher whole body taurine concentrations when compared to larvae fed unenriched rotifers. At the end of the Artemia phase, CYT whole body taurine concentrations varied among dietary treatments. Larval lengths and DWs were not significantly different among treatments at the end of the Artemia phase, suggesting that the taurine concentrations of unenriched Artemia were sufficient to support the growth of CYT larvae.

Taurine is an important amino acid derivative for marine and freshwater fish, especially during early development. We investigated the range of taurine concentrations that influence the growth and survival rates of California yellowtail (CYT; Seriola dorsalis) during transition from live feeds to microparticulate diets, as well as the extent to which nutrient leaching from the microparticulate diets affects these ranges. We tested particle‐assisted rotationally agglomerated (PARA) particles with four levels of taurine: 4 (low taurine; LT), 45 (medium taurine; MT), 93 (high taurine; HT) and 122 g/kg (very high taurine; VHT). Our results showed that CYT postlarvae had no significant differences in growth, survival and feed consumption rates between the MT, HT and VHT treatments. However, it should be noted that the PARA particles containing 122 g/kg (VHT) taurine were especially prone to leaching and may have had taurine concentrations as low as 34.9 g/kg before they settled on the bottom of the tank. Therefore, the actual dietary taurine concentrations experienced by the larvae were likely lower than the initial dietary concentrations. More research is needed to evaluate the potential nutrient toxicity of elevated dietary taurine concentrations for marine fish larvae and juveniles.

Owing to its high nutritional value and widespread availability, the legume alfalfa Medicago sativa (Linnaeus, 1753) is a possible feed for aquatic animals. In this study, a dried alfalfa chloroplast (DAC) product supplied by Virentia Inc., Quebec, Canada, was evaluated as a partial or total replacement for live microalgae (LM) in diets for juveniles of Perna perna and the Mesodesma mactroides—two species with high aquaculture potential in Brazil. In addition, trials were conducted with Venerupis philippinarum, a species commonly used in global aquaculture. Nine diets containing different ratios (based on dry weight) of live microalgae (Chaetoceros neogracile and/or Isochrysis galbana) and DAC were evaluated. With all three bivalve species, additions of DAC to partial microalgal rations increased final dry and organic weights, compared with those provided with partial algal rations alone. M. macrooides and P. perna appeared to utilize DAC to a greater extent than V. philippinarum as indicated by the higher final organic weights obtained by these two species when larger fractions of LM were substituted with DAC. Overall, the results of this study indicate that DAC supplements can be useful in supporting mussel and clam tissue growth when algal feeds are limited or unavailable.

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