Effects of Substrate Type and Fragment Size on Selected Physiological Characteristics of the Soft Coral Sarcophyton serenei (Tixier-Durivault, 1958)

The study was conducted to evaluate the simultaneous effects of substrate type and fragment size on self-attachment time, growth, survivorship rate, density of zooxanthellae, chlorophyll a content, and organic matter weight fraction of the soft coral Sarcophyton serenei over a 60-day indoor culture period. Four different substrate types were tested: dead coral, cement, ceramic tile, and PVC pipe, along with five fragment sizes with average diameters of 0.5, 1, 1.5, 2, and 2.5 cm. The results demonstrated that the optimal fragment size for S. serenei propagation was ≥ 1.5 cm, in combination with PVC pipe or dead coral substrates, which enhanced self-attachment, specific growth rate, survival, and organic matter content. However, these treatments did not enhance symbiotic algal density or chlorophyll a content, and no significant differences were detected between fragment sizes ≥ 1.5 cm combined with PVC substrates and those combined with dead coral. The results of this study provide essential data to improve the techniques of asexual propagation in this coral species, forming the basis for developing a sustainable aquaculture practice. This approach ensures a stable supply of ornamental corals, reduces pressure on wild populations, and offers a potential source of raw materials for the extraction of bioactive compounds.