The Banggai cardinalfish (Pterapogon kauderni), endemic to the Banggai Archipelago (Central Sulawesi), has been declared the Indonesian National Marine Ornamental Fish Mascot. Sea urchins (Diadema sp.) are a key P. kauderni microhabitat. The decline of urchin populations due to harvesting for human consumption has adversely affected P. kauderni populations. The purpose of the study was to develop artificial microhabitat from environmentally friendly materials (coir and cement) and to determine the effectiveness of this artificial microhabitat in terms of fish growth and survival. The research was conducted in July 2021 at the Water Quality and Aquatic Biota Laboratory, Tadulako University. Two treatments were used (P. kauderni with live urchin microhabitat = BBA; P. kauderni with artificial microhabitat = BBB) with 8 replicates. T-test analysis showed net growth in weight differed significantly (p<0.05) between treatments (higher in BBA), as did survival rate (higher in BBB), while net growth in length did not differ significantly. Based on the results, it was concluded that the sea urchin-like artificial microhabitat developed could be effective as a surrogate P. kauderni microhabitat, at least in a controlled environment, and shows promise for supporting the conservation of P. kauderni. The next stage will be trials in the natural environment.