Fishmeal Dietary Replacement Up to 50%: A Comparative Study of Two Insect Meals for Rainbow Trout (Oncorhynchus mykiss) Melenchón, Federico Pula Moreno, Héctor Julián Cardenete Hernández, Gabriel Ramón Black soldier fly Mealworm Fishmeal replacement Rainbow trout Aquaculture Fish nutrition This research was funded by ‘Instituto Nacional de Investigación Agraria y Alimentaria’, cofunded by European Regional Development Fund, grant number RTA 2015-00021-C03. The ‘Agencia Estatal de Investigación-Ministerio de Ciencia e Innovación’ supports the PhD contract of F.M., grant number BES2017-080567, cofunded by European Social Funds. The demand of optimal protein for human consumption is growing. The Food and Agriculture Organization (FAO) has highlighted aquaculture as one of themost promising alternatives for this protein supply gap due to the high efficiency of fish growth. However, aquaculture has been facing its own sustainability problem, because its high demand for protein has been traditionally satisfiedwith the use of fishmeal (FM) as themain source. Some of themost promising and sustainable protein substitutes for FM come frominsects. The presentmanuscript provides insight into an experiment carried out on rainbow trout (Oncorhynchus mykiss)with a 50%replacement of FMwith different larvae insectmeals: Hermetia illucens (HI), and Tenebrio molitor (TM). TMshowed better results for growth, protein utilization andmore active digestive function, supported by intestinal histological changes. Liver histology and intermediarymetabolismdid not showrelevant changes between insectmeals,while other parameters such as antioxidant enzyme activities and tissue damage indicators showed the potential of insectmeals as functional ingredients. 2022-03-18T08:27:01Z 2022-03-18T08:27:01Z 2022-01-12 journal article Melenchón, F... [et al.]. Fishmeal Dietary Replacement Up to 50%: A Comparative Study of Two Insect Meals for Rainbow Trout (Oncorhynchus mykiss). Animals 2022, 12, 179. [https://doi.org/10.3390/ani12020179] http://hdl.handle.net/10481/73535 10.3390/ani12020179 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España MDPI