Musseling up: The Uptake of Dissolved Amino Acids for Supplying Nutrition in the Nursery Rearing of Juvenile Greenshell Mussels ( Perna canaliculus )

ABSTRACT Land‐based nursery culture for bivalves offers an opportunity to improve the efficiency of bivalve aquaculture because seeding larger and nutritionally healthy juveniles reduces losses during the initial grow‐out stages. However, a major problem in establishing nursery culture for bivalves is the reliance on live microalgal food, which is labour‐intensive and expensive to prepare. In New Zealand, aquaculture is dominated by the Greenshell mussel ( Perna canaliculus ), yet little is known about the ability of these juvenile mussels to utilise dissolved amino acids as an alternative nutrient source. Providing dissolved nutrients as a substitute or supplement to live microalgae may be a viable approach to reducing feeding costs. The aim of this study was to determine whether juvenile Greenshell mussels (2 mm shell length) can absorb dissolved amino acids at rates sufficient to contribute to their nutrition in nursery culture. Uptake of glycine, d ‐asparagine and S ‐methyl‐ l ‐cysteine (1.0 mg mL −1 in seawater) was measured over 4 h. Mussels absorbed each of the three dissolved amino acids at different but constant rates over the 4 h, likely reflecting differences in transporter affinity, that is, glycine and S ‐methyl‐ l ‐cysteine 7.9 mg g −1 AFDW h −1 < d ‐asparagine 2.6 mg g −1 AFDW h −1 . These findings demonstrate that juvenile Greenshell mussels can uptake dissolved amino acids in quantities that are sufficient to provide a useful contribution to their nutrition, confirming their potential as a cost‐effective alternative in land‐based nurseries compared to wholly relying on feeding live microalgae.