LARVAL REARING 2. Artemia Production

Figure 27 10,000 Litre Parabolic Nursery Tanks, larvae gravity feed from Larval Rearing Area

Figure 28 10,000 Litre Parabolic Nursery Tank

Figure 29 70 Litre Artemia Hatching Vessels

Live Artemia nauplii are the most important food item available to the Hatchery.  The Artemia utilised should be first grade, 90% hatch rate and preferably sourced from the Great Salt Lakes in the United States of America.  The Artemia room houses six, 70 litre hatch vessels and one x 150 litre vessel (Figure 29).  Artemia cysts are vacuum sealed in 425 gram cans and the expected hatch rate is 270,000 nauplii per gram of cysts.  Cysts are added to the vessels as 213 grams per 250 litres of seawater (Figure 30). Hatching requirements are: temperature set at 30⁰C, full and constant aeration and continuous fluorescent lighting.  Nauplii hatch in 14 to 16 hours, and can be harvested from the conical vessels.  Aeration is ceased, the vessels are lidded and a fluorescent light at the clear base concentrates the nauplii to be drained into a 100 micron bag. Cysts float to the surface of the vessels. Nauplii are washed in freshwater and fed to larvae immediately or stored with aeration under refrigeration for later feeding.