Flow-through systems for culturing great scallop larvae

Rearing of great scallop (Pecten maximus L.) larvae was tested in static an d flow-through systems in order to improve intensive rearing methods and av oid bacterial problems. The static systems were: standard 300 litre tanks ( STD) and standard tanks supplied with an antibacterial agent (STD+A). The f low-through systems were: 500 l down-welling tanks (FLOW) and a 4700 l up-w elling 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 obtain ed in the SILO system. The type of rearing system did not affect larval gro wth.