Effects of cutting and fixing methods on artificial propagation efficiency of different reef-building corals

Cutting, cultivation and transplantation of coral fragments are the primary method for restoring coral reef ecosystems. However, the limited availability of reef-building corals hinders the coral reef ecological restoration. To address this issue, this study focused on three species of reef-building corals, namely Acropora digitifera, Porites lutea and Galaxea fascicularis. The aim was to improve the cutting and fixing methods for these coral fragments to enhance the efficiency of artificial propagation while maintaining their survival and growth rates. Commonly used tools for cutting and fixing were employed for the three coral species. The growth status of the corals was monitored to statistically assess their survival rates and polyp growth rates. The results showed that: Firstly, for Acropora digitifera, cutting along the central axis led to rapid growth of new tissues and polyps on the exposed skeleton layer, doubling the utilization rate. Secondly, for Porites lutea, vertically fixed thin-section fragments exhibited no tissue or polyp regeneration from the exposed skeletal interiors. Instead, new tissues and polyps slowly extended from the cut edges to cover the exposed areas. Thirdly, for Galaxea fascicularis, isolating individual polyps stimulated rapid polyp regeneration around the fragments, increasing utilization efficiency several-fold and showing a high application potential. These findings indicated that the cutting and fixing methods used significantly improved the utilization rates of Acropora digitifera and Galaxea fascicularis, providing a valuable technical support for coral artificial propagation.