Fishmeal Replacement with Hermetia illucens Meal in Aquafeeds: Effects on Zebrafish Growth Performances, Intestinal Morphometry, and Enzymology

Abstract

Fishmeal (FM) is still the most important protein source in aquafeeds. However, due to the reduction of wild fish stocks used for FM production, its manufacturing it is now unsustainable. Insect meal represents a valid alternative to FM, due to the low carbon footprint of its production and its high nutritional value. The aim of this study was to investigate the potentials of replacing FM with black soldier fly (Hermetia illucens) meal (HIM) in aquafeeds, using zebrafish as the animal model. Four diets were formulated with increasing HIM/FM replacement rate (the control diet contained 20% FM). Mortality rates, growth performances, and feed consumptions were measured, and fish intestine samples were collected for histological and enzymatic analysis. After 49 days, all groups almost tripled their initial body weight (cumulative body weight gain ranged between 143.9 and 155.2 mg), and no statistically significant differences among treatments were observed in relation to growth performances and histological traits. Contrarily, trypsin, alkaline phosphatases, and alpha amylase–glucoamylase activities were significantly reduced when the FM replacement rate was increased. In conclusion, HIM may represent an alternative to FM, since no adverse effects were observed when it was included up to 20% in the zebrafish diet, even when replacing 100% of the FM.

Dietary Supplementation with a Blend of Hydrolyzable and Condensed Tannins Ameliorates Diet-Induced Intestinal Inflammation in Zebrafish (Danio rerio)

“…Fish body weight was measured at the beginning (310,0 ± 118,28 mg; mean ± SD) and end of the trials. Before and during the experimental period (two weeks of acclimation and twelve days of treatments), animals were maintained in a water recirculating system at a temperature of 28 • C, which was monitored daily, as was the pH, electrical conductivity, and dissolved oxygen, as described by Fronte et al [14], according to the indications of Westerfield [38].…”

“…The different feeds were prepared as described by Royes and Chapman [39] and Fronte et al [14]. Briefly, the raw ingredients and TSP were subjected to grinding and homogenization in a mixer, followed by humidification, pelletization, and final drying in a forced-air oven (40 • C for 24 h).…”

“…The cyprinidae zebrafish (Danio rerio) is a well-established biomedicine and aquaculture research animal model [7][8][9][10]. As a model for aquaculture studies, zebrafish enables lower research costs and possesses a well-known digestive system from both the morphofunctional and microbiome points of view [11,12], making it a useful model to assess the relationship between nutrition and health [13,14]. As an omnivorous species, as reported by field observations of wild zebrafish [15], it can feed on both plant and animal proteins and represents a nutritional animal model for both carnivorous and omnivorous fish [13].…”

Influence of Hermetia Illucens Larvae Meal Dietary Inclusion on Growth Performance, Gut Histological Traits and Stress Parameters in Sparus Aurata

“…This could be partly due to the presence of subepithelial edema, which is one of the signs of inflammation that we have found especially in the HIM50 group. Conversely, Melenchon et al [89] in rainbow trout fed with a diet containing a 50% of Hermetia illucens meal as replacement of FM and Fronte et al [93] in zebrafish fed diets including increasing levels of full-fat Hermetia illucens meal (with respect to FM) did not observe any changes. Recently, Li et al [85] reported that a partial (40%) up a total substitution of partially defatted Hermetia illucens meal did not cause negative effects on gut morphology in Atlantic salmon, indicating a high tolerance of salmonids to high dietary HIM inclusion levels.…”

Excessive level of dietary insect protein negatively changed growth metabolomic and transcriptomic profiles of largemouth bass (Micropterus salmoides)

“…It is imperative for the aquaculture industry to find substitutes for fishmeal in the feeds of farmed fishes due to decreasing natural resources and the increasing price of fishmeal. HI meal has been previously used to partially replace fishmeal in the feeds of fish species including gilthead seabream ( Sparus aurata ) ( Bosi et al., 2021 ; Randazzo et al., 2021 ), rainbow trout ( Oncorhynchus mykiss ) ( Rimoldi et al., 2019 ), tongue sole ( Cynoglossus semilaevis ) ( Li et al., 2022 ) and zebrafish ( Danio rerio ) ( Fronte et al., 2021 ). The effects of replacing fishmeal with HI meal depend on fish species and the amount of substitution.…”