WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2013 45 (CONTINUED ON PAGE 46) better in captivity and survive longer (Oliver 2003, Ogavaand Brown 2001). We evaluated the aquaculture of clownfishes and damselfishes in brackishwater (salinity = 23 ppt) to demonstrate the technical feasibility of ornamental aquaculture in coastal areas of India. Clownfish Ten species of clownfish (Amphiprion sebae, A. clarkii, A. ocellaris, A. percula, A. nigripes, A. frenatus, A. akallopisos, A. sandaracinos, A. ephippium, and Premnas biaculeatus) and two species of sea anemone (Heteractics magnifica and Stichodactyla haddoni) were procured from traders and acclimated in 5000-L cement tanks for quarantine. After one month, fish were transferred to separate fiberglass reinforced plastic (FRP) tanks by species, along with a host anemone, and reared for two months. Water quality was maintained at levels suitable for ornamental aquaculture (temperature 27 ± 1 ºC, salinity 23 ± 1 ppt, pH 7.9 ± 0.2 and dissolved oxygen 6.5 ± 0.3 mg/L). Photoperiod was controlled on a 12:12 light-dark cycle and tanks were illuminated at 600 lux. Once pair formation occurred, couples were transferred to individual, 1000-L, gray, rectangular FRP tanks (Fig. 1) with a host anemone. Ceramic tile, dead coral pieces and live rocks were provided as substrate for egg laying. Among the three substrates, ceramic tile was most preferred for egg deposition. Clownfishes started spawning within 2-3 months of rearing, after pair formation. The periodicity of spawning ranged from 9-21 days, varying with species. Spawning mostly occurred in the morning (0900-1200 h) and usually lasted from 45-60 minutes. Capsule-shaped orange eggs were 2.0-2.3 mm long and 1.0-1.2 mm wide. After a female attached eggs to the substrate, the male would subsequently spread milt to fertilize the eggs. Clownfish had an approximate fecundity of 300-2000 eggs per spawning, which is specific to species and size of female. Amphiprion akallopsis deposited 300 eggs and A. sebae and A. clarkii laid a maximum of 2000 eggs. During the incubation period, males played the major role in parental care, which involved fanning and mouthing the eggs. The duration of egg incubation was 7-9 days, depending on water temperature. On the day of hatching, the egg capsule became very thin and transparent and the egg passed through a series of color changes from orange to black and finally to silver. Hatching occurred after sunset (178 h after spawning) and floating, newlyhatched larvae (3.8-4.1 mm) were gently collected with a beaker. Damselfish Ten individuals of three damselfish species (green damselfish Chromis viridis, humbug damselfish Dascyllus aruanus and regal damselfish Neopomacentrus cyanomus) were procured from traders. After quarantine, fish were transferred to individual, white-colored circular fiberglass tanks (1000-L) by species. Earthen pots (Fig. 2) and dead coral boulders were provided as substrate for egg laying. All tanks were provided with individual, locally-made submerged biofilters (Fig. 3). Photoperiod was controlled on a 12:12 light-dark cycle and tanks were illuminated with a fluorescent bulb at 600-900 lux. Damselfish started laying eggs after four months of rearing. Before spawning, broodfish actively cleaned the substrate using their mouths and fins. Spawning occurred in the morning. Females attached eggs to cleaned substrate, which were immediately fertilized by males. Fecundity was 1500-2500 eggs. Oval-shaped, transparent eggs measured 1.2-1.4 mm long and 0.6 mm wide. The substrate with a clutch of eggs was transferred to 500-L larval rearing tanks containing seawater on the evening of the third day after spawning. A gentle air flow was created near the egg clutch by placing an air diffuser beneath the substrate. Eggs hatched at night, after 3-4 days of incubation. Larval Rearing An algal stock culture of Nannochloropsis salina was maintained using F/2 medium under controlled conditions. Photoperiod was controlled on a 12:12 light-dark cycle with a light intensity of 4000 lux. An outdoor mass algal culture (batch culture) was prepared in 1000-L, white, circular, fiberglass tanks FIGURE 1. Spawning tanks for clownfish. FIGURE 2. Earthen pot with damselfish egg deposition.
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