The First Insight Into Full-Fat Superworm (Zophobas morio) Meal in Guppy (Poecilia reticulata) Diets: A Study on Multiple-Choice Feeding Preferences and Growth Performance

Insect meals are sustainable alternative protein sources in animal nutrition. However, the data on their application in petfood and ornamental fish nutrition are scarce. Thus the present study was undertaken to assess their usability in guppy (Poecilia reticulata) diets. The first experiment aimed to investigate the attractiveness of select insect meals for guppies, and the second evaluated superworm (Zophobas morio) meal monodiet effects. The first experiment (free-choice feeding test) lasted five days. Fish were given a choice between four attractants: fish meal, black soldier fly (Hermetia illuces) meal (HI), Madagascar cockroach (Gromphadorhina portentosa) meal (MC), and superworm (Zophobas morio) meal (ZM). The preliminary part of the study showed that the most frequently chosen attractant throughout the entire free-choice feeding test period was ZM. Based on the obtained results, the second part of the study was designed as a growth test with the use of a ZM monodiet compared to commercial feed. The experiment lasted 90 days, and 150 guppy fry were used. The fish were randomly divided into two groups (CON – commercial feed, ZM – Zophobas morio meal). No effects of dietary treatment were found in terms of survival rate, fish body length, or fish body length gain. The present study shows that ZM was the most preferred attractant and that a monodiet based on insect meal can be successfully applied in guppy fry nutrition.