Rearing cuttings of the soft coral Sarcophyton glaucum (Octocorallia, Alcyonacea): towards mass production in a closed seawater system

The octcoral Sarcophyton glaucum has a wide Indo-Pacific distribution and is known for its diverse content of natural products. The aim of the current study was to establish a protocol for rearing miniature cuttings of S. glaucum in a closed seawater system. In order to determine the optimal conditions for rearing, the survival, average dry weight, percentage of organic weight and development of the cuttings were monitored under different temperature, light, salinity and feeding regimes. At 26 degrees C, the highest dry weight was obtained, and at 20 degrees C, the highest percentage of organic weight. The dry weight of the cuttings increased with the light intensity, while under 35-130 mu Em(-2) s(-1), survival was high. Salinity did not affect any of the colonies' features. Feeding intervals of 7 and 30 days yielded a better result than of 2 days. A comparison of the colonies derived from the closed system with the colonies reared in a flow-through system, those reared in the sea and with field-collected colonies revealed the importance of environmental conditions in determining the features of the colonies. The study emphasizes the advantages of a closed seawater system in controlling the conditions needed for rearing cuttings of S. glaucum for targeted farming.