MarbleGrade

The aim of the MarbleGrade project is to transfer the AWI technology for voluntary size grading to the target species marbled crayfish (Procambarus virginalis). Together with the partner Merall Bioproducts GmbH, which specialises in aquaculture and the processing of these animals, the aim is to increase efficiency and animal welfare during breeding.

Due to its unique genetics, the marbled crayfish (Procambarus virginalis) is a suitable model organism for epigenetic research at the German Cancer Research Centre (DKFZ) in Heidelberg. In addition, this species offers great potential for breeding in aquaculture, as it is easy to reproduce and shows rapid growth. The animals can be kept in simple, closed systems and are resistant to environmental fluctuations. However, a significant problem is the different growth performance of the individuals, which leads to pronounced cannibalism. One way to effectively reduce cannibalism is to regularly size-sort the animals during the production cycle. The current manual sorting process is both time-consuming and labour-intensive and leads to a significant increase in cultivation costs.

Merall Bioproducts, a DKFZ spin-off project, is currently working on the husbandry of the species in aquaculture and its utilisation. However, the lack of a suitable and economically viable system for sizing represents one of the greatest challenges. As part of the AWI Innovation Fund project Grade Aid and the HGF validation project Sorted!, a system for the voluntary sizing of tropical shrimp is currently being scaled up and tested on a semi-commercial scale. This technology can be transferred to other crustacean species.

In the MarbleGrade project, it is planned to adapt the patented AWI technology to the specific requirements of the marbled crayfish and to enable sorting into different size groups. To this end, different sorting structures will be developed, built and tested on a laboratory scale. The most suitable structure will be selected and a prototype including frame and holder for crayfish cultivation will be designed and constructed. A full production cycle will be tested at Merall's cultivation facility to make iterative improvements and document the effects on marbled crayfish growth and mortality.