Physiological properties and tailored feeds to support aquaculture of marbled crayfish in closed systems

Abstract

The marbled crayfish (Procambarus virginalis) is a recently discovered freshwater crayfish species, which reproduces by apomictic parthenogenesis, resulting in a monoclonal, all-female population. The animals have become a popular source for nutritional protein in Madagascar and are increasingly being considered for commercial aquaculture. However, their potential has remained unclear and there are also significant ecological concerns about their anthropogenic distribution. We show here that the size and weight of marbled crayfish is comparable to commonly farmed freshwater crayfish. Furthermore, chemical analysis revealed a high chitin content in the marbled crayfish exoskeleton, which is a valuable source for the synthesis of chitosan and bioplastics. To allow the further evaluation of the animals in closed aquaculture systems, we developed tailored feeds that revealed an important role of methionine supplementation for animal growth. Additional analysis revealed a feed conversion rate of 1.4, which compares favorably to leading livestock for sustainable food production. Finally, we provide a concept for ecologically safe marbled crayfish aquaculture, based on key physiological characteristics that mitigate the invasive potential of the animals.