Effect of an enriched diet in global performance and transcriptomic response in Octopus vulgaris

Abstract

The culture of the common octopus, Octopus vulgaris, has been a big challenge for the aquaculture sector over the last decades. Animal settlement at the benthic phase was the main constraint to close the life cycle since massive mortalities occurred at the end of the planktonic stage. It is known now, that diet requirements might influence the successful of settlement more than any other culturing parameter. Indeed, a proper diet was the trigger element that allowed closing the life cycle on this species. In this study, a transcriptomic comparison on 20 days post-hatching paralarvae was carried out to compare the effect of a mixed enriched diet and Artemia-based diet. The whole paralarvae was used for RNA extraction and subjected to RNA-sequencing using the Illumina platform. Global performance in terms of weight and survival was significantly higher after feeding on the mixed enriched diet. A higher number of transcripts related to metabolism, biosynthesis and transport were up-regulated in Artemia-based diet. This might indicate that the digestion process was still ongoing at the moment of sampling or internal reserves were mobilized for energy obtaining due to a nutritionally deficient diet. Energy consuming processes seem to be largely prolonged after feeding on Artemia, especially considering that animals were under starvation for 12 hours before sampling. The enriched diet, on the other hand, might favor the proper development of crucial traits such as vision and neuronal development as transcripts related to crystalline formation and motor neuron preservation are higher expressed in these animals.