The influence of light
intensity on the density of different diatoms as feed for juvenile greenlip
abalone (Haliotis laevigata)
D. Watson, S. Daume, J. Prince, L. Beazley, B.
Knott-2004
Aquaculture, 235(1-4): 345-359
Abstract:
The diatoms Cocconeis sp. and Navicula
jeffreyi, were cultured in aquaria under high and low light levels.
Diatom density and juvenile Haliotis laevigata growth, survival and
behaviour were monitored. In contrast to N. jeffreyi, growth of Cocconeis
sp. was not inhibited in low light (<200 lx), however, the density of
both species increased in high light (800 lx). Juvenile H. laevigata
growth rates were strongly correlated to the density of N. jeffreyi
but not to the density of Cocconeis sp. Juvenile growth rates did not
differ between diatom species or shading condition. A reduction in the
photophobic behaviour of juvenile H. laevigata was observed in shaded
aquaria, suggesting that abalone are not strictly nocturnal feeders. Results
demonstrate the importance and effect of light intensity on the growth of
diatom species and the growth, survival and behaviour of juvenile H.
laevigata. Results also show that light intensity for diatom culture and
husbandry of juveniles in a hatchery needs to be considered carefully.