Largemouth bass (LMB) is a rapidly expanding food fish in the United States. Earthen ponds are primarily used for LMB culture, but high mortality rates have been reported during multiple production stages. Indoor, intensive recirculating aquaculture systems (RAS) may mitigate the high mortality rates observed during early rearing. Currently, there is a lack of information on optimal LMB feeding strategies. Replacing live feeds with artificial diets is critical, as culturing live feed is costly, labor-intensive, and prone to collapse. Therefore, the objective of this research was to determine the earliest time to wean fry onto artificial diets.
Mortality and water parameters were measured daily, including dissolved oxygen, pH, and temperature. Fry (n = 12) were sampled weekly (0, 7, 14, 21, and 28 DPH) for morphometric measurements and growth performance.
A decline in survival was detected when fry were fed Artemia up to 5 and 10 DPH (Fig. 2A). Fry fed only rotifers (Treatment 1) or only dry diet (negative control) were significantly smaller than treatments that received Artemia at 7-21 DPH (Treatments 2-5; Fig. 2B). Based on these findings, the earliest time LMB fry can be weaned off Artemia is 15 DPH. These results will help farmers make informed management decisions to enhance fry nutrition and production.