2.3. Feed production
Artemia nauplii were stocked in 670 l tanks at 5 Artemia ml−1 and
on-grown to approximately 8.0 mm in flow-through tanks receiving
a diet of blended brine shrimp food (consisting of rice pollard,
soyflour and wheat flour; Eyre Peninsula Aquafeeds Pty Ltd, South
Australia) and algae (T. Isochrysis and Chaetoceros muelleri). Prior to feeding to phyllosoma, gut bacteria in Artemia were minimised by
purging in dense cultures of C. muelleri (107 cells ml−1
), as described
by Tolomei et al. (2004), and 400 ppm formalin for 30 min before
rinsing with filtered seawater and feeding to phyllosoma culture
tanks. Artemia feeding rates were based on phyllosoma density and
kept consistent between treatments with the HD treatment receiving
three times more (1.38 g DM) than the LD treatment (0.46 g DM).
The length:mass relationship of Artemia cultured at IMAS was used
to determine DM of ration based on Artemia length. Uneaten Artemia
remaining from the previous meal were flushed from the tanks prior
to the next meal of Artemia.