Mealworm (Tenebrio molitor) Meal Supplementation in Commercial Diets Enhances Growth Performance and Nutritional Profile of Hybrid Catfish

Abstract

Fish feed accounts for over 60% of aquaculture production costs, with fishmeal becoming increasingly scarce and expensive. This study evaluated the effects of coating commercial diets with fortified mealworm (Tenebrio molitor) protein produced from larvae reared on fruit-waste substrates. An eight-week feeding trial was conducted using seven diets consisting of a commercial Blue Crown® fish feed coated with 2% or 4% mealworm protein derived from larvae reared on wheat bran (WB), wheat bran with watermelon rinds (WB/WR), and wheat bran with pineapple peels and watermelon rinds (WB/PP/WR), with an uncoated commercial feed as the control. Dietary proximate composition differed significantly, with crude protein ranging from 31.55% (D) to 38.22% (B2), lipid from 9.15% (A1) to 13.23% (C2), ash from 7.36% (A2) to 8.70% (C1), moisture from 7.96% (A1) to 11.45% (B2), and carbohydrate from 45.00% (C1) to 52.20% (A1). The results of the growth performance revealed that the weight (33.44 g), specific growth rate (1.27%) and feed conversion ratio (2.83) were highest in fish fed diet containing 2% mealworm protein reared exclusively on wheatbran. The survival rates were high across the diets and the water quality parameters were within acceptable limits for trials on catfish. Carcass proximate and mineral composition revealed no significant differences among the treatments, and was within nutritionally acceptable ranges. In Conclusion, the inclusion of mealworm protein at low levels improved growth performance without compromising the carcass nutrional quality, which supports the use of insect protein from fruit-wastes as sustainable alternative to fishmeal in aquaculture feeds.