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ThalaPrime W - Premium pathogen free freeze dried Thalassiosira weissflogii

ThalaPrime W is Provirons' pathogen free freeze dried Thalassiosira weissflogii alga for setting and post-set bivalve larvae and zoea-2 to mysis shrimp larvae.

ThalaPrime W - Premium pathogen free freeze dried Thalassiosira weissflogii

Thalassiosira weissflogii is one of the most extensively used microalgae in aquaculture. It is a rich source of both valuable ω-3 fatty acids EPA and DHA, but also phytosterols. In addition, it contains high levels of carotenoids/antioxidants such as fucoxanthin and beta-carotene.

ThalaPrime W consists of Thalassiosira weissflogii that is produced under the most stringently controlled conditions (HACCP and FCA certified by SGS (FCA certificate BE 01/1522.GF)). Thalassiosira weissflogii produced at Proviron accumulates high levels of the ω-3 poly-unsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid (DHA) present in a readily bioavailable form. It is freeze dried according to a proprietary process to yield a premium grade product with the longest shelf life, no nutrient leakage, maintenance of the correct lipid profiles and an ensured bioavailability of ω-3 poly-unsaturated fatty acids.

ThalaPrime W offers:

  • Optimal nutrient profile: High levels of the ω-3 poly-unsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), phytosterols, vitamins and pigments/antioxidants such as fucoxanthin and beta-carotene.
  • Single Cell dispersion: Excellent for filter feeders and Green Water Technique thanks to the single cell dispersion. ThalaPrime W remains in the water column for very long periods without fouling your tanks.
  • Gut development: Gives the larvae a head start by activating the digestive system.
  • Pathogen free:  No sourcing from natural salt water. No fish, shrimp, shellfish or other aquatic organisms (pathogen vectors) grown in the vicinity of our production. Constant biological monitoring.
  • Long shelf life: ThalaPrime W can be stored for 36 months in normal conditions. It does not need to be frozen or cooled.

Product leaflet

You can download the ThalaPrime W Product Leaflet here


  • ThalaPrime W is the perfect larval feed for sea cucumber, for shrimp or prawn from zoea-2 stages to mysis, and for setting and post-set bivalve larvae (oyster, clam, scallop, ...).
  • ThalaPrime W can also be used for green water treatment. Direct addition to your larval tanks improves larval performance, reduces stress, controls the bacterial environment and maintains the nutritional value of live prey.
  • ThalaPrime W is the easy-to-use back-up alternative for your live algae, available off the shelf at any time.


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Thalassiosira weissflogii has a proven track record for the cultivation of the following species:


  • Black tiger shrimp or giant tiger prawn (Penaeus monodon)
  • Whiteleg shrimp or King prawn (Litopenaeus vannamei)


  • Oyster
  • Clam
  • Scallop


  • Sea cucumber/sandfish (Holothuria scabra)
  • Sea urchin


Cell size (µm): 10-50 (median 15-18)
Cell count (cells/g): 4-6 10^9
Total neutral fat (%): 7-15
Protein content (%): 35-45
Water content (%): < 10
Ash content (%): < 40
Vibrio species (/25g): absent
Salmonella (/25g): absent
Clostridium perfringens (cfu/g): < 10
Mercury (mg/kg): < 0.1
Lead (mg/kg): < 10
Cadmium (mg/kg): < 1

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ThalaPrime W is a feed material belonging to categorie 7.1.2. (microalgae, dried) of the catalogue of feed material (Commission Regulation (EU) No 2017/1017).
ThalaPrime W is compliant with the following feed regulations:
  • EU No 2017/1017 - catalogue of feed material
  • EU No 767/2009 - placing on the market and use of feed and its amendments
  • EU No 183/2005 - requirements for feed hygiene
  • EU No 32/2002 - undesirable substances in animal feed