Assessment of the
performance of Pacific oyster (Crassostrea gigas) larvae fed with
fresh and preserved Pavlova lutheri concentrates
E. Ponis, R. Robert, G. Parisi, M. Tredici-2003
Aquaculture International, 11(1-2) : 69-79
Abstract:
The Prymnesiophycea Pavlova lutheri was
produced using a traditional technique (batch mode in carboys) and by an
innovative technique (semi-continuous mode in alveolar photobioreactor). Two
experimental feeding trials were carried out with Pacific oyster (Crassostrea
gigas) larvae with fresh and preserved (4 °C
and 1 °C) P. lutheri concentrates
used in monospecific and bispecific diets, in combination with fresh Chaetoceros
calcitrans forma pumilum. No differences in terms of gross
composition and larval performance were noticed between the fresh algae
biomass produced by the two techniques. The low temperatures allowed
preservation of the nutritional characteristics of the P. lutheri
fresh culture for the time period considered (27 days). The P. lutheri
concentrates preserved at 4 °C or 1 °C
did not differ substantially in terms of nutritional value. Larvae fed a
monospecific diet of P. lutheri, both fresh and preserved,
exhibited a modest growth rate (<2.1 µm
day-1), in some cases not significantly different from that
observed in the unfed larvae (the control), and a low survival rate. In
contrast, when Chaetoceros calcitrans forma pumilum was
used as a monospecific diet, good growth performance (>4.5
µm day-1) and a high survival
rate (>86%) were observed in larvae. A
substitution of 50% (trial 1) or 80% (trial 2) of fresh C. calcitrans
forma pumilum with the preserved P. lutheri concentrates
did not adversely affect growth rate or survival of C. gigas
larvae.
(Dipartimento di
Scienze Zootecniche, University of Florence, Via delle Cascine, 5, 50144
Firenze, Italy, e-mail of R. Robert: Rene.Robert@ifremer.fr)