FEATURE

Choosing the right algae

The Instant Algae product line offers the range of algae most highly prized for use in aquaculture. Each strain provides particular benefits, depending on such characteristics as nutritional content, cell size, palatability, and digestibility: Nannochloropsis—Provides high EPA, ARA, and cholesterol. Although it lacks DHA, so it cannot impart to rotifers the full nutritional value required by many larvae, it is a nearly ideal feed for mass-production of rotifers. Its small size (1.5-2 µm) and robust cell wall also enable it to persist in suspension for use as “greenwater” to provides beneficial turbidity and prevent depletion of the energy reserves of rotifers in larval tanks. Tetraselmis—Provides high EPA and cholesterol. Tetraselmis is very unusual among microalgae in containing significant taurine (ca. 10% of amino acids). Its relatively large cell size (10-12 µm) makes Tetraselmis an efficient feed for late larval and post-larval bivalves. Isochrysis “T-Iso” (Tisochrysis)—Provides no EPA but very high DHA, making it one of the most widely-used algae in aquaculture. Used as a component of bivalve larviculture and zooplankton grow-out diets, as well as supplemental DHAenrichment protocols for rotifers and Artemia. Pavlova—Provides a balanced EPA : DHA ratio and a variety of sterols, some of which have been shown to stimulate setting of bivalve larvae. Can be difficult for hatcheries to produce reliably. Thalassiosira weissflogii—Provides both EPA and DHA (many diatoms lack DHA), and so is one of the most widely used diatoms in aquaculture. Particularly valuable for shrimp larviculture because the large cell size (long dimension up to 15+ µm) facilitates extension of the algae feeding period until the end of the PL stage. Thalassiosira pseudonana—Similar to T. weissflogii, provides EPA and DHA, but its smaller cell size (long dimension 6-10 µm) is more suitable for earlier larval stages of shrimp and bivalves. Different Instant Algae products are optimized for a variety of different applications. Some single-species products are suitable for use alone for certain specialised purposes, but in general a combination of species provides more balanced nutrition. Users can combine products to create their own custom mixes, or they may prefer to use our combination products to provide optimal nutrition for bivalves (Shellfish Diet) or zooplankton (RotiGrow Plus, RotiGrow OneStep, and N-Rich products). https://reedmariculture.com/product_instant_algae.php 29 | June 2018 - International Aquafeed