Tetraselmis Phytoplankton

Tetraselmis

 is a genus of motile green phytoplankton widely used in marine aquaculture and reef keeping due to its exceptional nutritional density and ease of culture. 

Key Characteristics

• Appearance: Distinctive bright green unicellular algae, typically oval or pear-shaped, measuring 10–14 micrometres in size.

• Motility: Unlike many other phytoplankton, Tetraselmis is motile, using four flagella to swim through the water column, which helps it remain suspended and available to filter feeders.

• Nutritional Profile: It is considered an "all-rounder," boasting high protein levels (40–55% dry weight) and a balanced mix of amino acids, carbohydrates, and lipids.

• Role in Reef Tanks: It serves as a primary food source for corals (especially LPS and SPS), bivalves, and zooplankton like copepods and brine shrimp. 
  

Benefits for Your Marine System

• Nutrient Reduction: Actively consumes inorganic waste, including ammonia, nitrates, and phosphates, as well as CO₂, helping to stabilize water quality.

• Coral Growth & Color: Rich in pigments like chlorophyll and carotenoids (lutein, beta-carotene), which can enhance the natural coloration and vitality of corals.

• Digestibility: Features a robust but digestible cell wall that provides sustained-release nutrition compared to soft-walled species.

• Survival Rates: Often used in hatcheries to significantly improve the growth and survival rates of fish larvae. 
  

Culturing Tips

If you are looking to grow your own, Tetraselmis is relatively hardy:

1. Salinity: Maintain between 25–35 ppt (approx. 1.018–1.026 SG).

2. Light: Requires 12–16 hours of bright light daily.

3. Aeration: Use gentle, continuous aeration to keep cells suspended and prevent clumping.

4. Fertilizer: Utilize standard F/2 culture medium to provide necessary nutrients like nitrogen and trace metals.