<p>In this study, we used gelatin obtained from rainbow trout skin as a stabilizing and reducing agent for copper metal due to the biopeptides in the gelatin, which can provide a potential alternative gelatin source for the synthesis of hybrid flower-shaped copper nanoflowers. The objective of this study is to investigate the effect of different solvents (water, ethanol, and chloroform) and different copper concentrations (0.5, 2, 4, and 5 mM) on the morphology of copper hybrid nanoflowers (Cu-HNF) using gelatin obtained from fish skin. In this study, Cu-HNFs were synthesized for the first time using gelatin obtained from fish skins. Furthermore, in this study, biopeptides in gelatin obtained from rainbow trout skin were employed as a stabilizing and reducing agent for copper ions. In order to characterize the Cu-HNFs obtained, a series of analytical techniques have been applied. As a result, it was observed that the structures exhibited different morphologies at varying copper concentrations utilized in the synthesis of Cu-HNFs and distinct solvents in which gelatin was dissolved. This study represents the inaugural documentation in the literature of the synthesis of Cu-HNFs in an organic-inorganic composite utilizing fish skin, a byproduct of aquaculture processing.</p> Graphical Abstract <p></p>