Aquaculture Research, 2010, 41,1748^1758 doi:10.1111/j.1365-2109.2009.02475.x Rearing cuttings of the soft coral Sarcophyton glaucum (Octocorallia, Alcyonacea): towards mass production in a closed seawater system Ido Sella & Yehuda Benayahu Department of Zoology,George S.Wise Faculty of Life Sciences,Tel-Aviv University,Tel-Aviv, Israel Correspondence: I Sella, Department of Zoology,George S.Wise Faculty of Life Sciences,Tel-Aviv University,Tel-Aviv 69978, Israel. E-mail: [email protected] Abstract for diverse natural products with pharmaceutical or cosmetic value (e.g., Blunt, Copp, Munro, Northcote & The octcoral Sarcophyton glaucum has a wide Indo- Prinsep 2005; Slattery, Gochfeld & Kamel 2005; Sip- Paci¢c distribution and is known for its diverse con- kema, Osinga, Schatton, Mendola,Tramper & Wij¡els tent of natural products.The aim of the current study 2005), as well as for the reef-aquarium trade (Wab- was to establish a protocol for rearing miniature cut- nitz,Taylor, Grenn & Razak 2003). The increased de- tings of S. glaucum in a closed seawater system. In or- mand for these organisms has led to their massive der to determine the optimal conditions for rearing, harvesting (Castanaro & Lasker 2003) and has raised the survival, average dry weight, percentage of or- the need for e⁄cient farming methodologies (Ellis & ganic weight and development of the cuttings were Ellis 2002; Mendola 2003). monitored under di¡erent temperature, light, salinity Coral propagation has been commonly used for the and feeding regimes. At 26 1C, the highest dry weight production of daughter colonies, rather than harvest- was obtained, and at 20 1C, the highest percentage of ing naturally grown ones (e.g., Soong & Chen 2003; organic weight. The dry weight of the cuttings in- Fox, Mous, Pet, Muljadi & Caldwell 2005). This prac- creased with the light intensity, while under 35^ tice has been based on the ability of corals to repro- 130 mEmÀ 2 s À 1, survival was high. Salinity did not duce asexually (e.g, Delbeek 2001; Ellis & Ellis 2002). a¡ect any of the colonies’ features. Feeding intervals Captive-grown colonies, or ¢eld-collected ones, are of 7 and 30 days yielded a better result than of 2 days. used for the production of cuttings or fragments. The A comparison of the colonies derived from the closed latter are usually glued or attached by various means system with the colonies reared in a £ow-through to bases or stubs, until natural attachment is system, those reared in the sea and with ¢eld-col- achieved (Delbeek 2001). lected colonies revealed the importance of environ- Over the last decade, coral propagation in closed mental conditions in determining the features of the arti¢cial seawater systems has been commonly used, colonies. The study emphasizes the advantages of a making the process more simple and cost e¡ective closed seawater system in controlling the conditions (Borneman & Lowrie 2001; http://www.reefkeeping. needed for rearing cuttings of S. glaucum for targeted com). The advantage of these systems lies in their farming. ability to control abiotic and biotic parameters (Wheeler 1996; Borneman & Lowrie 2001; Abramo- Keywords: soft corals, closed seawater system, vitch-Gottlib, Katoshevski & Vago 2002). Such sys- Sarcophyton glaucum, coral farming, Red-Sea tems have been proposed as a source by which to obtain corals and other invertebrates with commer- cial value (e.g., Wabnitz et al. 2003; Sipkema et al. Introduction 2005), as well as for restoration and conservation A large variety of reef invertebrates, including soft purposes (Becker & Mueller 1999; Petersen, Laterv- corals (Octocorallia), have long been used as a source eer, Van Bergen, Hatta, Hebbinghaus, Janse, Jones, r 2010 The Authors 1748 Aquaculture Research r 2010 Blackwell Publishing Ltd Aquaculture Research, 2010, 41, 1748^1758 Rearing cuttings of the soft coral S. glaucum I Sella & Y Benayahu Richter, Ziegler,Visser & Schuhmacher 2006; Okuza- Experimental closed seawater system wa, Maliao, Quinitio, Buen-ursua, Lebata, Gallardo, We constructed a closed seawater system at Tel Aviv Garcia & Primavera 2008). University (TAU). The system comprised three 1m3 Species of the soft coral genus Sarcophyton (Octo- PVC tanks, each ¢lled with arti¢cial seawater (Red corallia) have a wide Indo-Paci¢c distribution and are Sea saltr) and 200 kg of live rocks obtained from Ei- known for the diverse content of their natural pro- lat (Gulf of Aqaba, northern Red Sea). Each tank was ducts (e.g., Look, Fenical, Matsumoto & Clardy 1986; provided with 40 Trochos dentatus snails for algal Tanaka, Yoshida & Benayahu 2005; Nguyen, Tran, grazing. Every 10 days, their faeces were removed Phan, Chau, Eun & Young 2008). S. glaucum (Quoy & from the bottom of the tanks, together with ca.5% of Gaimard, 1833) is the most common species of the the water volume, which was then replaced. A set of genus, also on the northern Red Sea reefs, where it 24 glass aquaria (30 L each) was connected to the was found to be a dioecious broadcaster with the on- tanks by 26-mm-diameter pipes. The aquaria were il- set of reproduction at the age of 6^10 years (Benaya- luminated by neon bulbs (22 W,400^800 nm, JEBO hu & Loya 1986). S. glaucum is zooxanthellate and daylight,12L:12D,35mEmÀ 2 s À 1 on the colony sur- extremely rich in natural products, which have been face). The water circulated from the aquaria to the studied extensively (e.g., Fridkovsky,Rudi, Benayahu, tanks, which were equipped with protein skimmers Kashman & Schleyer1996; Badria, Guirguis, Perovic, (JEBO 3500), a chiller (JEBO 2000, Zhongshan Zhen- Ste¡en, Muller & Schroder1998;Tanaka et al. 2005). hua Aquarium Accessories, Zhongshan, China) and The aim of the current study was to establish the a 5000 L per hour circulation pump (JEBO). The scienti¢c ground for a protocol suitable for rearing water temperature in each aquarium was controlled miniature cuttings of S. glaucum in a closed seawater using an individual heater (60 W). Salinity, tempera- system. Our objectives were to study the e¡ect of tem- ture and pH were monitored daily, and the nutrient perature, light intensity, salinity and feeding regimes levels weekly (nitrite o0.05 ppm, nitrate o10 p p m, on the survival, average dry weight, percentage of or- ammonia 0 ppm and 8.1^8.3 pH) (see Delbeek 2001). ganic weight and development of the cuttings. In addi- tion, colonies reared in a closed seawater system were compared with those reared in a £ow-through sea- Collection of colonies, preparation of cuttings water system in the sea and with ¢eld-collected ones. and experimental set-up Colonies of S. glaucum with a polypary diameter of 5^ 7 cm (the polyp-bearing part of the colony) were col- Materials and methods lected by SCUBA from three reef sites in Eilat (5^7 m, In a preliminary work, we examined attachment of August 2004^January 2007). For each experiment, the S. glaucum cuttings to stubs made of ceramic and we collected 10^15 colonies, growing at least 5 m plastic materials, using a cyanoacrylate adhesive apart in order to avoid the use of asexually produced (3M) and rubber bands.We also examined the mini- colonies (Benayahu & Loya1986). In order to prevent mal size of cuttings yielding the highest survivorship possible bias in the study, only colonies that did not (10^400 mm 2) (Sella 2007). Consequently,in the cur- contain gonads were used for formation of the cut- rent study, we decided to use cuttings measuring tings (see Okubo, Motokawa & Omori 2007). At the 36 mm 2 (6 Â 6 mm) with an average dry weight of Interuniversity Institute for Marine Science (IUI), 0.0077 Æ 0.0024 g and 8.864 Æ 2.461 average per- the colonies were placed in a £ow-through seawater centage of organic weight (n 5 30 random cuttings system for 3 days and all epibiotic organisms were re- from colonies used in the experiments; see‘Collection moved.The colonies were £own toTAU in plastic con- of colonies, preparation of cuttings and experimental tainers ¢lled with seawater and placed in thermally setup’). The cuttings were glued using a cyanoacry- isolated boxes. They were then maintained in the ex- late adhesive to cylindrical ceramic (Fig. 1a) stubs perimental system for a 1-month quarantine period, that we produced ourselves (clay WBB Fuchfs GmbH under conditions resembling the average ambient Ei- &CoR2502,burntat12001C for 12 h) at a cost of lat ones: salinity 40 ppt, pH 8.2 and 26 1C(IUIData 4 US cents (without labour). The stubs measured Base, http://www.iui-eilat.ac.il/NMP/Default.aspx). 5 cm in length and 1cm in diameter, with a hexago- For preparation of the cuttings, the colonies of nal indentation (ca. 3 mm deep and 7^8 mm wide) at S. glaucum were handled with latex gloves. The peri- one end, into which the cuttings were attached. meter of the polypary was removed using a scalpel r 2010 The Authors Aquaculture Research r 2010 Blackwell Publishing Ltd, Aquaculture Research, 41,1748^1758 1749 Rearing cuttings of the soft coral S. glaucum I Sella & Y Benayahu Aquaculture Research, 2010, 41, 1748–1758 (see section ‘General observations’ ahead), and the http://www.iui-eilat.ac.il) (10^15 cuttings per aquaria: remaining part was then kept for future regeneration March^May 2005). Seawater at 20 1C was circulated (Sella 2007). The perimeter of the polypary was thor- from the tanks to all the aquaria. The 23,26 and 29 1C oughly rinsed with arti¢cial seawater for removal of seawater temperatures were obtained using 60^300 W mucus and cellular debris, and 36 mm2 (6 Â 6mm) heaters with thermostats.