Enhanced biological performance of intensive sea bream (Sparus aurata) larviculture in the presence of phytoplankton with long photophase

N. Papandroulakis, P. Divanach, M. Kentouri-2002

Aquaculture, 204(1-2): 45-63
Abstract:

Sea bream larvae were reared under intensive conditions either with (pseudo-green water technique) or without (clear water technique) the addition of phytoplankton in the rearing tanks, under 24- or 18-h photophases. Phytoplankton presence in the rearing medium resulted in 44±17% survival and individuals of 2.0±0.2 mg wet weight after 20 days of rearing. With the clear water method, both survival and growth decreased to 16±6% and 1.1±0.2 mg, respectively. The daily consumption rate (as milligram of carbon consumed per milligram body carbon) at the beginning of exogenous feeding was 0.5/day for all experimental conditions. At later stages, individuals reared with phytoplankton present had a daily consumption rate of about 0.7/day, while those reared with the clear water technique presented consumption rates from 1.0 (for 24-h photophase) to 1.9/day (for 18- photophase). The mean food assimilation efficiency of the larvae, expressed as a Food Conversion Index (FCI), was between 6.3±1.4 (for 18-h photophase) and 8.2±1.2 (for 24-h photophase) for the individuals reared in the presence of phytoplankton. For larvae reared using the clear water technique, FCI was between 12.8±2.4 (for 24-h photophase) and 20.1±5.3 (for 18-h photophase).

(Aquaculture Department, Institute of Marine Biology of Crete, P.O. Box 2214, GR71003, Heraklion, Crete, Greece, Tel.: +30-81-346860; fax: +30-81-241882, e-mail: npap@imbc.gr)

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