Evaluation of the efficacy of aquaculture feeds for the climbing perch Anabas testudineus: replacement of fishmeal by black soldier fly Hermetia illucens prepupae

Abstract

The growth of the climbing perch Anabas testudineus reared on lower protein feeds with the replacement of fishmeal (FM) by prepupae of the black soldier fly (BSF) Hermetia illucens was examined. Three different feeds were prepared: control feed (treatment 1; T1) with only FM as a source of animal protein [32.5% crude protein; CP]; lower protein feed (T2) with both FM and BSF (30.0%); lowest protein feed (T3) with only BSF prepupae as a source of animal protein (25.0%). After 123 days of rearing, survival rates were ca. 82% in all treatments. The final weights in T2 and T3 (84–92 g/fish) were comparable to that in T1 (ca. 85 g/fish) despite the lower protein levels of feeds in T2/T3. Similarly, CP levels of fish at harvest in T2/T3 were comparable to T1 (17–18%), while the crude fat level in T3 (ca. 14%) was significantly greater than in T1/T2 (ca. 12%). The level of ash in T3 (ca. 4.1%) was significantly lower than in T1/T2 (5.4–5.7%). The protein efficiency ratio in T3 (ca. 1.3) was significantly greater than in T1/T2 (0.9–1.1), and the protein retention in T3 (ca. 21.9) was significantly greater than in T1 (ca. 16.4). Similar final weights observed between T1 and T2/T3 suggested that BSF protein can be better assimilated by climbing perch than FM. The results suggest that BSF prepupae are an efficient substitute for FM in climbing perch feed, and potentially allow for a reduction of feed protein levels.