Yellow Perch (YP) production is notoriously challenging during the larval stage. Intensive YP larviculture has traditionally used expensive and unpredictable methods in supplying rotifers at first feeding. The rotifer cultivation process requires immensely more labor than most other diet regimens and it is not easily replicable. However, the YP industry has consistently struggled to solve and simplify the inefficient live feed stage at first-feeding. The objective of this study was to determine if decapsulating Artemia could sufficiently replace and remove traditional rotifer feeding without inhibiting larval YP performance.
At 6 days post-hatch (dph), ~4,150 YP larvae were volumetrically stocked into six 280L black tanks with a starting water inflow rate of 2 L/min. Clay (10-16 NTU), overhead light (during feeding only), and water surface sprinklers (90o and 45o) were used to deter cannibalism and improve feed intake and swim bladder inflation. Two treatment groups with 3 replicates, Rotifer (RG) and Decapsulated Artemia (DA), were fed ad libitum from first-feeding (7 dph) until 21 dph. The DA group was fed two separate strains of Artemia. The DA group was given San Francisco DA until 9 dph, then switched to the larger Salt Lake DA until 17 dph. The RG group was fed Brachionus plicatilis until 9 dph, then fed traditional (non-DA) Salt Lake Artemia only until 17 dph. From 17 dph both groups were slowly transitioned to formulated diet, until fully weaned at 21 dph when the feeding trial ended. Weight and body length measurements were taken at 11 dph just after the RG group had fully transitioned to feeding on Artemia, and at 21 dph just after the groups fully weaned to the formulated diet.
At 11 dph, the DA group had significantly (P < 0.05) longer body length and greater body weight than the RG (Table 1). At 21 dph the DA group remained significantly (P < 0.05) longer in total body length and greater in total body weight than the RG. No significant difference (P > 0.05) in survival was found between the RG (53.64 ± 9.18%) and DA (55.70 ± 20.17%) groups. Using a simple Artemia decapsulation protocol the study creates an alternative route for the cost-intensive larval YP stage, eliminating the need for rotifer culture completely.