Application of stable isotope analysis to evaluate the assimilation of protein sources in juvenile slipper lobsters (Thenus australiensis)

Stable carbon and nitrogen isotope analyses were used to evaluate the contribution of five protein sources to the growth of juvenile slipper lobster Thenus australiensis. Protein sources tested were fish meal, krill meal, lupin meal, soybean meal and a squid by-product meal. A commercial in confidence basal mix was utilised to produce five experimental feeds containing 30% of each protein source. Juvenile lobsters were fed daily at 5% of their body weight for 12 weeks. Lobster performance was assessed by survival, feed intake and growth performance, and the effects of protein source on nutrient assimilation and discrimination factor were determined. The squid by-product meal, soybean meal, and krill meal produced better growth performance and survival. The specific growth rate on lupin meal was significantly (p