As food insecurity becomes a growing issue, global food sectors are forced to maximise production whilst conserving the worlds remaining resources. The aquaculture sector is one of the fastest growing protein sectors. However, many sought after species are carnivorous, with high dietary protein requirements, often delivered in the form of wild caught fish (fishmeal; FM). The current demand for fishmeal is beginning to outweigh supply, prompting the increased importance of the management of fishery resources and the progression towards a more sustainable industry from a food security perspective.
Insects are a natural part of many freshwater and marine carnivorous finfish diets. Black soldier fly larvae (Hermetia illucens ; BSF) are of particular interest as a substitute to FM as they efficiently convert organic waste (e.g., fruit and vegetable waste ) into their own biomass, resulting in high protein and fat concentrations. Current literature reports the use of BSF in several aquaculture species diets, however results are variable. This may be attributed to trials adopting either a defatted insect meal (DBSF) or a whole insect meal (WBSF). To this date, no study has directly compared the performance of the two insect meal products.
The aim of this research was to evaluate the effects of BSF on juvenile barramundi (Lates calcarifer) growth, well-being and feed utilisation. Eight experimental diets contained graded levels of either DBSF or WBSF as a dietary replacement to FM or plant-based protein . Each diet was randomly allocated to one of 24 tanks in a blocked design, with three tanks per diet and 24 fish (38.38
g ± 0.23) per tank. Fish were hand fed the experimental diets, once daily, for 91 days. At the conclusion of the trial, weight and fork length were recorded.
The results showed that barramundi growth performance, well-being and feed utilisation did not differ between the eight experimental diets ( P > 0.05; Table 1). This study, therefore, demonstrates BSF suitability as a protein source. Furthermore, the results suggest that BSF can be utilised as either a defatted or whole product, and in replacement to FM.