Growth of six species of bivalve molluscs (Crassostrea gigas, Tapes japonica, Mercenaria mercenaria, Crassostrea virginica, Mytilus edulis and Ostrea edulis) was compared in a waste recycling-aquaculture system. Tests were conducted at experimental temperatures of 15 and 20° C, over the period November 1975 to May 1976. Experimental animals were fed algae, predominantly Phaeodactylum tricornutum, grown in large outdoor cultures enriched with secondary treated sewage effluent. C. gigas, T. japonica and O. edulis grew well. M. mercenaria, C. virginica and M. edulis exhibited poor growth. C. Gigas exhibited a greater increase in total live weight at 20° C (134 . 8% vs 128 . 4%) but a greater increase in mean dry weight at 15° C (106 . 5% vs 59%). Similarly, at 15° C T. Japonica exhibited consistently higher increments of both live weight (94% vs 52%) and dry weight (481% vs 269%). |
