live food aquaculture training course artemia biology and strains

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Artemia Biology and Strains


It is the ability of the Artemia to form dormant embryos or cysts that makes the Artemia nauplii the most widely used food item for the culture of fish and shellfish larvae.

After harvesting and processing, cysts are packed into cans or buckets and become storable 'on demand' live feed.

Artemia as live food; advantages


Artemia as live food; advantages

Resting cysts can be stored for yearsLive nauplii can be available within 24-36 hSecurity/backup at breakdown of rotifer

cultures Tailor-made bioencapsulation according to the

species nutritional requirementsRobust upon variation in environmental

parameters


Phylum: ArthropodaClass: CrustaceaOrder: AnostracaFamiliy: Artemidae

Systematics


Collection of cysts from the surface

• large amounts of cysts are produced and released when environmental conditions deteriorate• the cysts float to the surface in large concentrations• at this stage, they are harvested and dried for the aquaculture and aquarium industry by commercial companies


Dry resting cysts in diapause

Dry resting eggs (cysts) has an inactive metabolism and the embryo do not develop further as long as the cysts are kept dry or under anoxic conditions

Main techniques for terminating diapause are dehydration, freezing and treatment with hydrogen peroxide

http://www.aquaculture.ugent.be/coursmat/artbiol/arc04.htm


Hydration and activation

Upon immersion in seawater, the cysts hydrate and become spherical

Embryo resumes its reversibly interrupted metabolism at a water content of 60%

http://www.aquaculture.ugent.be/coursmat/artbiol/arc05.htm


Cyst Hatching

Outer membranes of the cyst burst after about 24 hours

Embryo leaves the cyst shelll surrounded by the hatching membrane


Pre-nauplius stage is developing into Instar I before hatching

Emergence of hatching membrane Characheristics:

colored brownish-orange due to the presence of yolk

three pairs of appendages : antennae which have a

locomotory function, sensorial antennulae rudimentary mandible

an unpaired red ocellus is situated in the head region between the antennulae.

Parasol stage and hatching


Stage: Instar II (metanauplius)

Second larvae stage Instar II, functional digestive system, ingest particles of 1-50 µm Is reached about 8 hours after hatching


Further development

Undertakes about 15 molts until it reaches the 10th instar, with the following differention; the body elongates patricles is filtered and ingested by

the setae of the antennae paired lobular appendages which will

differentiate into the thoracopods are budding in the trunk-region


Sex differentiation at 10th Instar

Male

Female

Adult female (1 cm)


Uterus filled with nauplii

Good conditions;ovovivipary

Uterus filled with resting eggs

Extreme conditions;Ovipary

Copulation

Reproduction


Cyst Biology Cyst shell consist of 3 layers; Alveolar layer

Protection against UV and mechanical disruptionCan be removed by hyopoclorite (decapsulation)

Outer cuticular membraneProtects embryo from larger molecules than CO2

Embryonic cuticleTransparent and elastic layer, develops into hatching membrane during incubation


Different strains found all around the world


Variability between strains of Artemia

Nutritional valueSize and energy contentHatching quality (hatching rate; nauplii/100

cysts; hatching efficiency; nauplii/g cysts)Number of cysts/gGrowth rate of naupliiSpecific cysts characteristics


Size and energy content (I)

Selection of strains with regard to mouth size

Example of gape with length in cod (figure)

Prey size to gape ratio varies between 0,4 to 1 in cod

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

4 4,5 5 5,5 6 6,5 7 7,5 8

Standard length (mm)

Gap

e (m

m)

Puvanendran et al. 2004. Can. J. Zool. 821380-1389.


Size and energy content (II)

Size, individual dry weight and energy content of Artemia instar I nauplii from different cyst sources hatched in standard conditions (35g.l-1, 25°C)

cyst source length (mm)

dry weight (µg)

energy content (10-3 Joule)

San Francisco Bay, CA-USA 428 1.63 366

Macau, Brazil 447 1.74 392

Great Salt Lake, UT-USA 486 2.42 541

Shark Bay, Australia 458 2.47 576

Chaplin Lake, Canada 475 2.04 448

Tanggu, Bohai Bay, PR China 515 3.09 681

Aibi Lake, PR China 515 4.55 -

Yuncheng, PR China 460 2.03 -

Lake Urmiah, Iran 497 - -


Growth of nauplii

Growth of Artemia nauplii from different cyst sources under standard culture conditions (7 days, darkness, 10 instar I nauplii/25 ml, 35g.l-1, 25°C, fed with Dunaliella viridis)

cyst source growth expressed as % recorded for reference strain

(SFB, batch 1)

San Francisco Bay, CA-USA, batch 1

96

San Francisco Bay, CA-USA, batch 2

96

Macau, Brazil, batch 1 98

Macau, Brazil, batch 2 103

Great Salt Lake, UT-USA, batch 1 125

Great Salt Lake, UT-USA, batch 2 127

Shark Bay, Australia 95

Chaplin Lake, Canada 130

Tanggu, Bohai Bay, PR China 110

Aibi Lake, PR China 105

Yuncheng, PR China 109


Specific cysts characheristics

Generally three supplies of small cysts: San Fransisco Bay, Great Salt Lake and Vietnam

Type KE (cyster/g)

KP (%)

CD(um) T0 T90 DHA (mg/g)

EPA mg/g)

HUFA

AF Cysts (INVE) 223.000 69 241 - - 0,8 11,2 12,5 Bass Entree Cysts (INVE)

281.000 - 232 - - - - 5,3

ARGENTEMIA Platinum Label (Argent)

330.000 –400.000

90+ <450 9 18 3,5% 8,0% -


Specific cysts characheristics (II) Supplies of large cysts: San Fransisco Bay, Great Salt Lake, Russia

and China

Type KE (cyster/g)

KP (%)

CD(um) T0 T90 DHA (%)

EPA (%)

HUFA

Top grades (Premium, Gold)

260.000 90 450-475 8 15 3,0 5,5 -

Medium Grades (Silver, Grade A)

240.000 80 500-525 9 16 2,0 3,0 -

Low Grade (Bronze, Grade B)

220.000 - - - - - - -


Size of nauplii after 24 h enrichment

Type Length (μm) Width (μm)EG 630 186AF 500 172

AF480 520 182BE480 520 182

live food aquaculture training course artemia biology and strains

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