Live Feeds: ArtemiaLive Feeds: Artemia

Developed by the Harbor Branch ACTED staffDeveloped by the Harbor Branch ACTED staff

Live FoodsLive Foods

• Fish larvae must be fed live foods Fish larvae must be fed live foods

which have the nutrition and enzymes which have the nutrition and enzymes

(exogenous) they need, before their (exogenous) they need, before their

own digestive system is formed.own digestive system is formed.

• After the fish has developed its own After the fish has developed its own

digestive system, then weaning to dry digestive system, then weaning to dry

feed can begin.feed can begin.

Live FoodsLive Foods• The two main live feeds commonly used : The two main live feeds commonly used :

– RotifersRotifers– Artemia (brine shrimp)Artemia (brine shrimp)

• Other live feeds include:Other live feeds include:– Mollusc trochophore larvaeMollusc trochophore larvae– CiliatesCiliates– CopepodsCopepods– Wild planktonWild plankton

Live FoodsLive Foods

Most commercial hatcheries rely on Most commercial hatcheries rely on

rotifers and Artemia, for their ease of rotifers and Artemia, for their ease of

production, cost and reliability.production, cost and reliability.

RotifersRotifers• Rotifers can be produced using algae, yeast, Rotifers can be produced using algae, yeast,

or other custom products, or a combination.or other custom products, or a combination.

• Rotifer production range from 100 to 10,000 Rotifer production range from 100 to 10,000 animals per ml.animals per ml.

• Rotifers are usually maintained in larvae Rotifers are usually maintained in larvae tanks at a density of 5 to 30 per ml of larval tanks at a density of 5 to 30 per ml of larval tank water.tank water.

Brine Shrimp, ArtemiaBrine Shrimp, Artemia

Photograph by HBOI

Brine Shrimp (Artemia)Brine Shrimp (Artemia)

• Artemia can be hatched in 17 liter Artemia can be hatched in 17 liter

containers with hatches of 5 to 10 million.containers with hatches of 5 to 10 million.

• Artemia are maintained at less than 1 per ml Artemia are maintained at less than 1 per ml

of of culture water.culture water.

Brine Shrimp (Artemia)Brine Shrimp (Artemia)• Newly hatched brine shrimp have Newly hatched brine shrimp have

maximum nutritional value.maximum nutritional value.• Artemia lose their nutritional value after Artemia lose their nutritional value after

10 - 12 hours.10 - 12 hours.• At this time Artemia begin to feed and At this time Artemia begin to feed and

may be enriched with various products may be enriched with various products including algae.including algae.

• After 24 hours, the enriched Artemia is After 24 hours, the enriched Artemia is fed to larvae.fed to larvae.

Brine Shrimp (Artemia)Brine Shrimp (Artemia)• Most enrichment products increase the fatty Most enrichment products increase the fatty

acid content of the shrimp which is beneficial acid content of the shrimp which is beneficial

to larvae.to larvae.

• Other beneficial products can be Other beneficial products can be

incorporated into Artemia, including:incorporated into Artemia, including:

– ProbioticsProbiotics

– MedicationsMedications

Conventional Hatching for Marine FishConventional Hatching for Marine Fish(No de-capsulating)(No de-capsulating)

1. 8 a.m. Disinfect cysts with chlorine and hydrate cysts for 1 hour in freshwater. 1. 8 a.m. Disinfect cysts with chlorine and hydrate cysts for 1 hour in freshwater.

2. Chlorinate hatching saltwater, de-chlorinate, and check for residual chlorine.2. Chlorinate hatching saltwater, de-chlorinate, and check for residual chlorine.

3. 9 a.m. Drain cysts into net, rinse and add to saltwater. Add de-foamer.3. 9 a.m. Drain cysts into net, rinse and add to saltwater. Add de-foamer.

4. Next day 8 a.m. Turn off air and let settle until shells, nauplii and unhatched 4. Next day 8 a.m. Turn off air and let settle until shells, nauplii and unhatched

cysts are separate, about 15 minutes. Drain unhatched cysts on the floor, cysts are separate, about 15 minutes. Drain unhatched cysts on the floor,

then drain shrimp in net, stopping before the shells begin.then drain shrimp in net, stopping before the shells begin.

5. Rinse shrimp with salt water, and then put in a bucket of saltwater.5. Rinse shrimp with salt water, and then put in a bucket of saltwater.

6. Remove as many floating shells as possible with a baster.6. Remove as many floating shells as possible with a baster.

7. Feed to larvae.7. Feed to larvae.

Hatching for Freshwater FishHatching for Freshwater Fish(No de-capsulating)(No de-capsulating)

1. 8 a.m. Add salt to freshwater.1. 8 a.m. Add salt to freshwater.

2. Add cysts straight from the can.2. Add cysts straight from the can.

3. Next day 8 a.m. Turn off air and let settle until shells, nauplii 3. Next day 8 a.m. Turn off air and let settle until shells, nauplii

and unhatched cysts are separate, about 15 minutes. Drain unhatched and unhatched cysts are separate, about 15 minutes. Drain unhatched

cysts on the floor, then drain shrimp in net, stopping before the shells begin.cysts on the floor, then drain shrimp in net, stopping before the shells begin.

4. Rinse shrimp with freshwater.4. Rinse shrimp with freshwater.

5. Feed to larvae.5. Feed to larvae.

Hatching with De-capsulated cystsHatching with De-capsulated cysts

1.1. 3 p.m. Add de-capsulated cysts to seawater. Add de-3 p.m. Add de-capsulated cysts to seawater. Add de-foamer.foamer.

2. Next day 7 a.m. Turn off air and drain immediately 2. Next day 7 a.m. Turn off air and drain immediately into net and rinse.into net and rinse.

3. Feed to larvae.3. Feed to larvae.

Advantages of De-capsulating Advantages of De-capsulating

1.1. Cysts must be disinfected with chlorine when using Cysts must be disinfected with chlorine when using Artemia for saltwater, to kill bacteria such as Artemia for saltwater, to kill bacteria such as Vibrio. Vibrio.

2. Cysts do not need to be hydrated before hatching, saving 2. Cysts do not need to be hydrated before hatching, saving time.time.

3. With no shells, nauplii can hatch quicker with less 3. With no shells, nauplii can hatch quicker with less expenditure of energy (fat content), increasing their expenditure of energy (fat content), increasing their nutritional value.nutritional value.

Advantages (continued) Advantages (continued)

4. Hatching time is reduced from the normal 24 hours4. Hatching time is reduced from the normal 24 hours

to 16 hours at 30˚C (86˚F). Nauplii lose their nutritional to 16 hours at 30˚C (86˚F). Nauplii lose their nutritional

value over time, so the extra 8 hours saved means a nauplii value over time, so the extra 8 hours saved means a nauplii

with higher fat content.with higher fat content.

5. Quicker hatching time results in smaller, more uniform-sized 5. Quicker hatching time results in smaller, more uniform-sized

nauplii suitable for the smallest sized larvae.nauplii suitable for the smallest sized larvae.

6. There are no shells or unhatched cysts to separate from the 6. There are no shells or unhatched cysts to separate from the

nauplii. Even unhatched cysts can be eaten by larvae. nauplii. Even unhatched cysts can be eaten by larvae.

Advantages of De-capsulating Advantages of De-capsulating 7. There are no shells or unhatched cysts accumulating7. There are no shells or unhatched cysts accumulating

on the surface of larval tanks. Shells or unhatched cysts on the surface of larval tanks. Shells or unhatched cysts

can lodge in the esophagus and gut and kill larvae.can lodge in the esophagus and gut and kill larvae.

8. Hatching percentage increases compared to conventional8. Hatching percentage increases compared to conventional

hatching of unde-capsulated cysts.hatching of unde-capsulated cysts.

9. It is cost efficient as the price of Artemia has doubled.9. It is cost efficient as the price of Artemia has doubled.

10. As Artemia supply can fluctuate, even poorer grades 10. As Artemia supply can fluctuate, even poorer grades

(quality) of cysts (such as Grade A or B) can be used.(quality) of cysts (such as Grade A or B) can be used.

Disadvantages of De-capsulationDisadvantages of De-capsulation

1. De-capsulation requires skilled labor as the window of 1. De-capsulation requires skilled labor as the window of

de-capsulation is only 2 to 4 minutes. Any errors in de-capsulation is only 2 to 4 minutes. Any errors in following procedures result in loss of time and cost of following procedures result in loss of time and cost of Artemia cysts and chemicals.Artemia cysts and chemicals.

2. For large scale hatcheries when several cans must be hatched 2. For large scale hatcheries when several cans must be hatched

every day, following the disinfection / hydration techniques every day, following the disinfection / hydration techniques is more time and cost efficient.is more time and cost efficient.

De-capsulating Brine Shrimp De-capsulating Brine Shrimp

Approximately 275,000 cysts/ gram Approximately 275,000 cysts/ gram

produce produce

200,000 – 250,000 nauplii/ gram200,000 – 250,000 nauplii/ gram

oror

90 – 113 million per 1 pound can (454 grams)90 – 113 million per 1 pound can (454 grams)

Materials For De-capsulatingMaterials For De-capsulating

1. Pre-cool (5ºC) 1 gallon of salt water and 1 gallon of liquid 1. Pre-cool (5ºC) 1 gallon of salt water and 1 gallon of liquid chlorine (10%) in a refrigerator for at least 2 days.chlorine (10%) in a refrigerator for at least 2 days.

2. Dissolve 20 grams (1/16 cup) of sodium hydroxide Na(OH)2. Dissolve 20 grams (1/16 cup) of sodium hydroxide Na(OH)22

beads in 30 ml (1/8 cup) of freshwater. Caution mixture is beads in 30 ml (1/8 cup) of freshwater. Caution mixture is very hot and can burn skin. Do not inhale fumes!very hot and can burn skin. Do not inhale fumes!

3. Dissolve 1/4 cup of sodium thiosulfate in a 1 liter beaker of 3. Dissolve 1/4 cup of sodium thiosulfate in a 1 liter beaker of freshwater.freshwater.

4. Prepare 4 gallons of brine solution (5 lbs. of crystal salt 4. Prepare 4 gallons of brine solution (5 lbs. of crystal salt dissolved in 5 gallon capacity bucket of freshwater).dissolved in 5 gallon capacity bucket of freshwater).

5. 1 pound can of Brine Shrimp cysts.5. 1 pound can of Brine Shrimp cysts.

Photograph by HBOIPhotograph by HBOI

MethodMethod For De-capsulatingFor De-capsulating

1. Aerate cysts for 1 hour in 15 liters of freshwater 1. Aerate cysts for 1 hour in 15 liters of freshwater

in a brine shrimp net suspended in a hatching cone. in a brine shrimp net suspended in a hatching cone.

2. Rinse cysts briefly in freshwater.2. Rinse cysts briefly in freshwater.

3. Add the Na(OH)3. Add the Na(OH)22 solution to 2 liters of chilled salt water. solution to 2 liters of chilled salt water.

Discard remaining salt water.Discard remaining salt water.

Photograph by HBOI

Method Method For De-capsulatingFor De-capsulating

4. Add cysts to empty clean cone.4. Add cysts to empty clean cone.

5. Add the 2 liters of salt water mixture. Aerate vigorously.5. Add the 2 liters of salt water mixture. Aerate vigorously.

6. Add 2 liters of chilled bleach to cone.6. Add 2 liters of chilled bleach to cone.

7. After 2 - 4 minutes, cysts will turn bright orange.7. After 2 - 4 minutes, cysts will turn bright orange.

Photograph by HBOI

Photograph by HBOI

Photograph by HBOI

Photograph by HBOI

Photograph by HBOI Photograph by HBOI

Methods (continued)Methods (continued)

8. Add 1 liter of sodium thiosulfate solution and 15 seconds.8. Add 1 liter of sodium thiosulfate solution and 15 seconds.

9. Turn of the air, drain, rinse with water in a brine shrimp net.9. Turn of the air, drain, rinse with water in a brine shrimp net.

10. Add 2 liters of brine solution to a clean cone. Add cysts and 10. Add 2 liters of brine solution to a clean cone. Add cysts and

rinse net with more brine and fill up to the line for the required rinse net with more brine and fill up to the line for the required

number of cups. For example, the number of cups (18) times 200 mlnumber of cups. For example, the number of cups (18) times 200 ml

= 3.6 liters water and cysts.= 3.6 liters water and cysts.

Photograph by HBOI

MethodMethod (continued)(continued)

12. Aerate slowly for 18 hours.12. Aerate slowly for 18 hours.

13. With continued aeration, drain cysts into 13. With continued aeration, drain cysts into

16 to 24 (average 18) - 200 ml containers 16 to 24 (average 18) - 200 ml containers

14. Refrigerate for up to 2 weeks.14. Refrigerate for up to 2 weeks.

Photograph by HBOI

Photograph by HBOI

Photograph by HBOI

Photograph by HBOI

Photograph by HBOI

De-capsulation costs De-capsulation costs per pound can per pound can

Liquid chlorine Less than $2.00Liquid chlorine Less than $2.00

Sodium hydroxide Less than $0.25Sodium hydroxide Less than $0.25

Sodium thiosufate Less than $0.25Sodium thiosufate Less than $0.25

Labor time Less than 30 minutesLabor time Less than 30 minutes