Shrimp waste meal (Pandalus borealis) as an alternative ingredient in diets for juvenile European lobster (Homarus gammarus, L.)

The use of sustainable ingredients in the formulation of aquafeeds remains ever important. The European lobster (Homarus gammarus) is an emerging species for aquaculture, the success of which relies on knowledge of its nutritional requirements and the selection of dietary ingredients that facilitate viable production and future commercialization. In this study, we investigated the feasibility of using shrimp waste meal (SWM) as an ingredient in formulated diets for juvenile lobsters (stages VII – VIII, ~ 164 mg) during an 8-week feeding experiment. The experimental diets were isoproteic (~ 54% crude protein) and isolipidic (∼ 11% crude fat), in which either 7%, 14%, 21%, or 28% of the dietary protein was supplied by SWM. Experimental diets were benchmarked against a control diet without SWM (SWM 0%). Diet performance was evaluated based on survival, body mass gain, carapace length increment, and moulting cycle duration. Nitrogen metabolism was evaluated from the nitrogen excretion rates of individual lobsters, determined before and following the ingestion of a single meal. The exoskeleton colouration of individual lobsters was assessed using digital colour analysis at the end of the growth trial. The results indicate that the inclusion of SWM at 28% protein significantly enhanced survival and had no effect on growth performance, postprandial nitrogen metabolism, and exoskeleton colouration. Therefore, we recommend the use of SWM, at least up to 28% of dietary protein, as a potential alternative ingredient in the formulation of future commercial feeds for juvenile H. gammarus.