1. Plankton Culture for Feeding Larval Fish and Shellfish
LaDon Swann
Mississippi-Alabama Sea Grant Consortium
Auburn University

2. Shellfish Larval Culture

3. Larval Rearing Trocophore D-Hinge or Straight Hinge Size 50-60 microns
6-12 hours post-fertilization
D-Hinge or Straight Hinge
Size microns
24-48 hours post-fertilization
Bivalve Shell
Velum - Swimming and Feeding organ

4. Larval Rearing Veliger or Umbo Larvae Pediveliger or “Eyed” Larvae
Size microns
Stage last 8-12 days
Well defined umbo
Pediveliger or “Eyed” Larvae
Size >300 microns
Pigmented eye-spot
Muscular foot

5. Phytoplankton Production
Feeding Larvae
Cell Size 4-8 microns
Species
Isochrysis galbana
Chaetoceros gracilis
Nannochloris sp.
Chlorella sp.
Pavlova lutheri

6. Pavlova lutheri Morphology Salinity Temperature Culture media
Golden brown
Spherical with 2 flagella
3-6 µm
Salinity
8-32 ppt
Temperature
11-26 °C
Culture media
Guillards f/2
Proximate Analysis
52% Protein
24% Carbs
29% Fat

7. Isochrysis galbana Morphology Salinity Temperature Culture media
Tahiti (T-Iso strain)
Golden brown
Cells spherical with 2 flagella
5-6 µm length, 2-4 µm wide
Salinity
8-32 ppt
Temperature °C
Culture media
Guillards f/2
Proximate Analysis
47% Protein
24% Carbs
17% Fat

8. Chaetoceros gracilis Morphology Salinity Temperature Culture media
Golden brown diatom
Medium-size 12 µm wide, 10.5 µm long
Cells united in chains
Salinity
ppt
Temperature °C
Culture media
Guillards f/2 with Si
Proximate Analysis
28% Protein
23% Carbs
9% Fat

9. Plankton for Shellfish
Broodstock and Spat
Cell Size microns
Species
Tetraselmis sp.
Green
Thalassiosra sp.
Diatom

10. Tetraselmis sp. Morphology Salinity Temperature Culture media
Ovoid green cells
14 to 23 µm L X 8 µm W
4 flagella
Salinity
28-36 ppt
Temperature
22-26°C
Culture media
Guillards f/2
Proximate Analysis
55% Protein
18% Carbs
14% Fat

11. Thalassiosra sp. Morphology Salinity Temperature Culture media
Golden brown diatom
Cells united in chains
Barrel-shaped
Non-motile
4 µm
Salinity
26 – 32 ppt
Temperature
22-29 °C
Culture media
Guillards f/2 with Si
Other characteristics

12. Micro Algae Culture Culture Water Sterilization Nutrient Enrichment
Inoculation
Cell Counts
Harvest and Feeding
Stock Culture

13. Culture Water Sources Salinity Seawater Saltwater wells
Prepared seawater
Salinity
26-32 ppt

14. Sterilization Methods Heat Pasteurization Autoclave
80 C and cool naturally
Autoclave
Sodium Hypochlorite (bleach)
0.5 ml/L (10 drops)
Neutralize: ml sodium thiosulfate (248 g/L) per liter
Hydrochloric acid (muriatic)
0.2 ml/L (4 drops)
Neutralize: Na2CO g/L

15. Nutrient Enrichment Nutrients Conc. (mg/l Seawater) Guillard’s f/2
NaNO3 75
NaH2PO4.H2O 5
Na2SiO3.9H2O 30
Na2C10H14O8N2.H2O (Na2EDTA)
4.36
CoCl2.6H2O
0.01
CuSO4.5H2O
FeCl3.6H2O
3.15
MnCl2.4H2O
0.18
Na2MoO4.2H2O
0.006
ZnSO4.7H2O
0.022
Thiamin HCl
0.1
Biotin
0.0005
B12
Guillard’s f/2
Part A and B
0.5 ml/L each part
Na2Si03 for diatoms

16. Inoculation Culture vessels
1,000 ml flask
18.7 L (5 gal.) Carboy (glass)
178 L (47 gal) Transparent Tank
Add enough algae to give a strong tint to the water
100, ,000/ml
Lighting
Types
Sunlight
Fluorescent
VHO fluorescent
Metal halide
Highest Densities: 24/7

17. Cell Counts Peak Algae Density Hemacytometer I. Galbana T. pseudonana
10-12 million cells/ml
10-14 days
2 wk stability
T. pseudonana
4 million cells/ml
3 days
5 day stability
Hemacytometer
Count total in centermost 1 mm
Multiply by 10,000
Product = number/ml
Motile cells should be killed

18. Harvest and Feeding Larvae Density Algae Density Tank cleared in 24hrs
5-10 larvae/ml
Algae Density
Wk 1 = 50,000 cells/ml
Wk 2+ = 100,000 cells/ml
Onset of spatting = 200,000/ml
Tank cleared in 24hrs
Liters to feed = (TD x V)/CD
TD = Target Density (1,000s/ml)
V = Volume of larval tank (thousands of L)
CD = Cell Density (millions/ml)

19. Harvesting and Feeding
Batch
Total harvest occurs once or over several days
Semi-Continuous
Works well with diatoms
Part of the algae remains in the vessel
New media is added to replenish the algae removed

20. Stock Culture Purchase pure strain Avoid contamination Holding
No aeration
Half filed container
Redundancy
Holding
Test tubes
Conical flasks
Transfer
1 drop/wk for T. pseudonana
1 drop/2 wk for I. galbana

21. Marine Fish Larval Culture
Relies on zooplankton

22. Marine Rotifer Brachionus plicatilis
Culture units
40L plastic bags
40L cone-bottomed tanks
Temperature C
Salinity 26 ppt

23. Rotifers Laboratory production 100 to 200+ mm size 2-3 week life span
small size suitable as first food

24. Feeding Marine Fish Rotifers Typical first food in hatchery
Feed algae or yeast
Enrichment needed

25. Artemia
Feeding of older larvae

26. Use of copepods