Flow-through systems for culturing great scallop larvae

Rearing of great scallop (Pecten maximus L.) larvae was tested in static and flow-through systems in order to improve intensive rearing methods and avoid bacterial problems. The static systems were: standard 300 litre tanks (STD) and standard tanks supplied with an antibacterial agent (STD+A). The flow-through systems were: 500 l down-welling tanks (FLOW) and a 4700 l up-welling tank (SILO).Bacteral counts ranked the systems in the following order SILO < FLOW < STD+A < STD. In spite of low bacterial numbers, increased larval survival was not demonstrated in the FLOW system compared to the STD system. The highest survival on day 17 (> 90%) and day 22 (52%) after fertilisation was obtained in the SILO system. The type of rearing system did not affect larval growth.