Physiological responses of Siberian sturgeon (Acipenser baerii) juveniles fed on full-fat insect-based diet in an aquaponic system

Matteo Zarantoniello,Giorgia Gioacchini,Stefano Ratti,Nunzio Isidoro,Paola Riolo,Andrea Osimani,Francesca Tulli,Valentina Notarstefano,Valentina Nozzi,Cristina Truzzi,Vesna Milanović,Federico Girolametti,Lorenzo Freddi,Gloriana Cardinaletti,Elisabetta Giorgini,Ike Olivotto,Basilio Randazzo

doi:10.1038/s41598-020-80379-x

Matteo Zarantoniello, Giorgia Gioacchini + Show 15 more

Open Access

https://doi.org/10.1038/s41598-020-80379-x

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Abstract

Over the last years, the potential use of Black Soldier Fly meal (BSF) as a new and sustainable aquafeed ingredient has been largely explored in several fish species. However, only fragmentary information is available about the use of BSF meal-based diets in sturgeon nutrition. In consideration of a circular economy concept and a more sustainable aquaculture development, the present research represents the first comprehensive multidisciplinary study on the physiological effects of a BSF diet during sturgeon culture in an aquaponic system. Siberian sturgeon (Acipenser baerii) juveniles were fed over a 60-days feeding trial on a control diet (Hi0) and a diet containing 50% of full-fat BSF meal respect to fish meal (Hi50). Physiological responses of fish were investigated using several analytical approaches, such as gas chromatography-mass spectrometry, histology, Fourier Transformed Infrared Spectroscopy (FTIR), microbiome sequencing and Real-time PCR. While aquaponic systems performed optimally during the trial, Hi50 group fish showed lower diet acceptance that resulted in growth and survival reduction, a decrease in hepatic lipids and glycogen content (FTIR), a higher hepatic hsp70.1 gene expression and a worsening in gut histological morphometric parameters. The low feed acceptance showed by Hi50 group sturgeon highlighted the necessity to improve the palatability of BSF-based diet designed for sturgeon culture.

Highlights

Over the last years, the potential use of Black Soldier Fly meal (BSF) as a new and sustainable aquafeed ingredient has been largely explored in several fish species
This aspect has been recently addressed by Truzzi et al.[39]. These authors developed an enrichment procedure to increase insects’ PUFA content that allowed to include up to 50% of BSF prepupae meal compared to fish meal (FM) in zebrafish diet without impairing fish growth and welfare[38]. Because of this positive result, this same enriched full-fat BSF dietary inclusion percentage was chosen for the present study, expecting to obtain more promising results respect to Caimi et al.[32] that evidenced a significant reduction of feed consumption and growth performance in Siberian sturgeon juveniles fed on a diet in which FM was 50% replaced with highly defatted BSF larvae meal
The results showed that the inclusion of a 50% enriched full-fat BSF prepupae meal negatively affects fish growth and survival

Summary

Introduction

The potential use of Black Soldier Fly meal (BSF) as a new and sustainable aquafeed ingredient has been largely explored in several fish species. Results obtained on zootechnical performances, fillet fatty acid composition, liver and gut integrity, expression of genes involved in fish growth, stress and immune response and gut microbiome represent the first multidisciplinary investigation on the physiological effects of BSF-based diets in sturgeon juveniles.

Results

Conclusion