The cherry barb, Puntius titteya, is an extensively cultured ornamental fish species in the United States, with a monthly production of approximately 60,000 individuals satisfying current market demands. Although existing culture protocols are reliable, refining these methods could reduce production costs without diminishing yield. A primary expense of P. titteya culture arises from the reliance on live Artemia spp. nauplii as a first feed, which, despite supporting acceptable larval survival and growth rates, can incur costs related to the purchase of cysts, decapsulation, and feed administration. Inert feeds, such as microparticulate diets (MDs) and liquid Artemia substitutes, present viable options with appropriate nutritional profiles and particle sizes. However, the absence of motility in these diets may reduce larval feeding response, risking feed waste, degraded water quality, and wasted money. This issue may be mitigated by enhancing ingestion rates of microparticulate diets with feed attractants—powdered amino acids that stimulate larval olfactory senses to theoretically boost larval feeding and survival. Additionally, liquid diets such as Liqualife® and EZ-Artemia® are designed to mimic the smell, taste, and size of Artemia spp. nauplii, thus presumably maintaining the larval feeding response.
Three feed attractants (L-alanine, betaine, L-tryptophan) were evaluated in a series of larviculture trials where attractants were top-dressed onto commercially available diets and fed to larval P. titteya for 7 days. Results show L-alanine and L-tryptophan both increased survival with inclusion rates of 0.5% and 0.25%, respectively (Fig 1A, C). Inclusion of betaine did not affect larval survival after 7 days (Fig 1B). Two brands of liquid diets, LiquaLife® and EZ-Artemia®, were tested in a 14-day trial to investigate the potential of replacing either 50% or 100% of Artemia spp. nauplii. Neither larval survival nor growth were improved when including liquid diets, however EZ-Artemia® did render better survival than LiquaLife® at 100% inclusion. These results indicate that Artemia spp. can be reduced during larviculture of P. titteya, however further investigation into weaning practices and feeding density is warranted.