Artemia – its role and production requirements Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Hatching of Artemia Preparation of the tank – clean with detergent, disinfect and rinse Fill tank with preheated water and add aeration and heating. Disinfect the water. Disinfection of the cysts Add to hatching tank Harvest. Live food aquaculture training course www.aquatrain.org

Artemia hatching characteristics Tank: Any Size/Shape (1-10 m3) Temp: 28-30 °C (Preheated Water/Heat Exchange) Salinity: 30-40 ppt Oxygen: > 4 ppm pH: > 8 (Ph control with NaHCO3 or NaOH) Illumination: 2000 Lux at Water Surface Density: 2-4 kg/m3 Hatch Controller : 100 ppm at T0 Water Treatment: Filtered and Chlorinated/Neutralized Aeration : Very Strong ( Open End ) Artemia are required for sea bass and bream in two development stages. The post hatch stage or instar 1 phase of higher grade AF artemia are used as a transition phase from rotifers. In the case of sea bass and clear water techniques this grade of artemia is the initial feed used and rotifers can in fact be avoided. As the larvae grow however enriched metanaupli are used The hatching characteristics and environmental conditions required for artemia are shown here. Live food aquaculture training course www.aquatrain.org

Strong aeration and bright lighting is essential in hatching phase Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Harvesting of Artemia Disconnect heater, increase oxygen to about 10ppm then stop aeration and oxygen Within 10-15 minutes the nauplii will separate from the empty cyst shells – the empty cyst shells float and the nauplii will crowd above the tip of the conical near a light source.( 100-150W incandescent spot) Drain the nauplii from the tank and rinse well before transferring them to the storage tank or enrichment tank. Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Artemia separation is achieved through their positive photo tactic response Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Careful rinsing at harvest is again essential to ensure as clean a product as possible for the larvae. It is however important to rinse well all live food before storage or feeding to these rather sensitive larvae. Live food aquaculture training course www.aquatrain.org

Decapsulation versus disinfection A complete contamination free and sterile product Separation problems after hatch are avoided Disinfection 50g/l cysts 20 minutes in 200 ppm active chlorine- continuous aeration rinse and add to hatching tank Cysts known to be contaminated fungi and bacteria Improves hatching yields Live food aquaculture training course www.aquatrain.org

Pathogen risk in Artemia Artemia nauplii are heavily contaminated with bacteria, esp. Vibrio sp. Correlation between bacterial flora in the larval intestines and the flora of live food Risk exists that potential pathogens are transferred via the food to the larval tanks Cyst decontamination, hatching and enrichment micro floral controllers are used. Decapsulation or cyst sterilization is used to avoid the transfer of disease from the artemia to the larvae and both at the hatching phase and later during the enrichment phases specialized products are used to reduce and control the microbiological loading and development. Hatch controller and the DC Selco product range are examples of these developments. Live food aquaculture training course www.aquatrain.org

Hatching percentage and efficiency Hatching percentage is the number of Artemia nauplii produced per 100 cysts. A good product will have a hatching percentage of +/-90% The hatching efficiency is the number of nauplii produced per gram of cysts. A good products will yield +/- 230,000 nauplii per gram of cysts Live food aquaculture training course www.aquatrain.org

Enrichment / Harvest and storage of Artemia nauplii Enrichment to meet the nutritional requirements of the fish Enrichment can only take place once the nauplii have started feeding – coincides with the molt into second Instar stage Long term/short term enrichment Live food aquaculture training course www.aquatrain.org

Artemia enrichment characteristics Tank: Any Size/Shape (1-10 m3) Temp: 28-30 °C (Preheated Water/Heat Exchange) Salinity: 30-40 ppt Oxygen: > 4 ppm pH: > 8 (Ph control with NaHCO3 or NaOH) Illumination: Natural light conditions Density: 200-500 million nauplii/m3 depending on method Hatch Controller : 100 ppm at T0 Water Treatment: Filtered and Chlorinated/Neutralized Aeration : Very Strong (Open End ) Artemia are required for sea bass and bream in two development stages. The post hatch stage or instar 1 phase of higher grade AF artemia are used as a transition phase from rotifers. In the case of sea bass and clear water techniques this grade of artemia is the initial feed used and rotifers can in fact be avoided. As the larvae grow however enriched metanaupli are used The hatching characteristics and environmental conditions required for artemia are shown here. Live food aquaculture training course www.aquatrain.org

Harvesting of enriched metanauplii Rinsing into 100 micron net Rinsing has to be done until no emulsion is left in the outflowing water to avoid problems with oil films in larval rearing tanks. Metanauplii are now ready for direct feeding or for cold storage for later use. Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Artemia enrichment enables total HUFA enrichment levels of up to 60mg/g Through emulsion enrichment products the artemia has be turned into a powerful tool for the bioencapsulation of essential fatty acids,and other nutritional and therapeutic substances Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Artemia cold storage at 6°C to maintain optimal nutritional value until feeding Post harvest and prior to feeding artemia may be kept at low temperatures to avoid bacterial development and to ensure undiminished enrichment levels. Conditions such as these can be maintained all day. Live food aquaculture training course www.aquatrain.org

Cold storage of Artemia nauplii Freshly hatched Artemia nauplii e.g. AF and enriched nauplii can be stored at 4-10 C for 24 hours. Cold stored nauplii slow down their metabolism and do not consume their energy reserve and can remain in Instar I (AF) or Instar II or III stage. (enriched artemia nauplii) If left at 25 C the HUFA content and in particular the DHA content can drop by 33% after 6 hours and 67% after 12 hours. Live food aquaculture training course www.aquatrain.org

Ongrowing of Artemia nauplii Advantages Increased biomass ( 30% on dry weight basis) Reduced cyst requirement through more efficient use of artemia metanauplii. Improved nutritional profile, higher digestible energy profile Improved larval growth and stress resistance. Disadvantages Further 24-48 hours after enrichment procedure Increased tank requirement Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Artemia requirements                   Sea bream         General assumptions         1) Artemia hatch rate (millions/kg cysts)   200   2) Max. daily need of AF/m3 larval rearing volume (M nauplii) 2,0   3) Hatching volume (m3/kg cysts)     0,4 (2.5g/l) 4) AF Artemia need per million juveniles 2g (kg cysts) 4,0   5) AF Artemia cost (drs/kg)         6) Max. daily need of EG/m3 larval rearing volume (M nauplii) 10,0   7) EG Artemia need per million juveniles 2g (kg cysts) 95   8) EG Artemia cost (drs/kg)         9) Enrichment stocking density (m3/100 million nauplii) 0,5   10) Selco need per 100 million nauplii (kgs)   0,10   11) Selco/Essential enrichment cost (drs/kg)                   Annual production target (2g juveniles)             No of larval batches 5 5 5 5 Initial larval rearing vol (m3) 62 123 185 308 Daily AF Artemia requirement (kgs cysts) 0,62 1,23 1,85 3,08 AF hatching volume (m3) 0,2 0,5 0,7 1,2 No of 0.25m3 tanks required 2 4 4 6 No of 0.5m3 tanks required 2 2 Total AF Artemia consumption (kgs cysts) 8 16 24 40 Total Cost of AF Artemia (Mdrs) 0,00 0,00 0,00 0,00 Daily EG Artemia requirement (kgs cysts) 3,08 6,15 9,23 15,38 EG hatching volume (m3) 1,2 2,5 3,7 6,2 No of 1m3 tanks required 1 2 4 No of 2.8m3 tanks required 1 1 1 2 Total EG Artemia consumption (kgs cysts) 190 380 570 950 Total Cost of EG Artemia (Mdrs) 0,00 0,00 0,00 0,00 Enrichment tank volume (m3) 3 6 9 15 No of 2.8m3 tanks required 1 2 3 5 No of 4.5m3 tanks required Total tank volume (m3) 5 9 14 23 Total Selco consumption (kgs) 38 76 114 190 Total Cost of Selco enrichment (Mdrs/yr) 0,00 0,00 0,00 0,00 Live food aquaculture training course www.aquatrain.org