For the sake of sustainability and ecosystem preservation, it is crucial to look for alternate protein sources for aquatic organisms fed in captivity. In the current study, many biomarkers were used to evaluate the potential applications for earthworms (Eisenia foetida) in aquaponic systems as alternative fishmeal for feeding tilapia (Oreochromis niloticus). A four-month feeding experiment using Nile tilapia (O. niloticus) was conducted to determine the impact of substituting 25% of the fish meal in the feed formula with earthworms (Eisenia foetida).  Growth performance, food consumption, haematological parameters, biochemical parameters, and histochemical invistigation as well as growth hormone gene expression values have been evaluated in O. niloticus. Our data indicated that final weight, weight gain, feed conversion ratio (FCR) and feed efficiency ratio (FER), in addition to haematological parameters and biochemical parameters, showed non-significant differences between fish fed a normal diet and fish consumed an earthworm diet under aquaponic systems. In contrast, fish get a regular diet; the gut and liver of tilapia fed an earthworm diet showed a normal histological structure, no indication of any particular pathology, and a normal amount of protein and carbohydrates. Growth hormone level expression in muscle of fish fed earthworm was similar to fish fed a normal diet. To summarise, the partial incorporation of earthworm meals in the diets of O. niloticus has a substantial and favourable influence on Tilapia's health status, implying that earthworm meal is appropriate as an animal protein source in the diet of Tilapia in an aquaponics system.