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

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.

Hermetia illucens and Poultry by-Product Meals as Alternatives to Plant Protein Sources in Gilthead Seabream (Sparus aurata) Diet: A Multidisciplinary Study on Fish Gut Status

“…Moreover, HM has been reported to have beneficial effect on gut physiology in different cultured fish species (as reviewed by Gasco et al [80]). The beneficial effects on fish gut health have been mainly attributed to the presence of certain HM bio-active compounds, such as chitin and medium-short FAs [17,35,44,62,81], exhibiting immune-stimulating, antimicrobial, and/or anti-inflammatory properties [36,82].…”

“…A semi-quantitative evaluation of the distal intestine morphology, based on mucosal fold height, mucosal fold fusion, enterocyte supranuclear vacuoles, and sub-mucosa width, was performed, as previously described by Uran et al [57] and Zarantoniello et al [17].…”

“…To date, besides histological and molecular approaches, target organ responses to dietary challenges were successfully investigated by means of a spectroscopic approach, Fourier Transform Infrared Imaging (FTIR) spectroscopy, which was shown to be able to provide information on gut intestine absorption and liver biochemical composition in different fish species [5,16,17].…”

Evaluation of Nutritional Composition of Pure Filamentous Fungal Biomass as a Novel Ingredient for Fish Feed

“…Therefore, regardless of fish life stage, supplementation of 1% of each LA and ALA can meet the requirements for highly unsaturated fatty acids (HUFAs) [16]. Due to the fact that many farmed fish, including marine fish and larvae, are poor in synthesizing LC-PUFA such as DHA and EPA from other PUFAs, similar to other tested alternative protein sources, it cannot be considered as a single fat supplier to the feed, however, possessing other functional nutrient such as EAAs emphasizes its suitability for addition as a protein source in the fish feed [40,42]. Inclusion of the required EFAs and particularly PUFAs have resulted in improved growth in several fish species, including salmonids, channel catfish, halibut etc.…”

Insect-Based Feed Ingredients for Aquaculture: A Case Study for Their Acceptance in Greece

“…Insects are highly nutritious, convert feed efficiently to body mass, can be grown on organic side-streams and agricultural by-products, whereas their rearing is described by low water and land requirements and reduced gas emissions [ 18 , 19 ]. The use of insect meals as a fishmeal replacement has been successfully evaluated for a range of fish species, such as the European sea bass [ 20 ]; trout, Oncorhynchus mykiss (Walbaum) [ 21 , 22 , 23 ]; Nile tilapia, Oreochromis niloticus (L.) [ 24 , 25 ]; gilthead seabream [ 26 , 27 ]; the Siberian sturgeon, Acipenser baerii Brandt [ 28 ]; the clownfish, Amphiprion ocellaris Cuvier [ 29 ]; or the zebrafish, Danio rerio (Hamilton) [ 30 ], and shrimps [ 31 ]. By the EU Regulation 2017/893 in 1 July 2017, the exploitation of insect protein in fish diets has been allowed in Europe [ 32 ].…”