牡蛎鳃的发生与研究

ON THE DEVELOPMENT OF GILLS IN THE OYSTER CRASSOSTREA GIGAS

The development of gills in oyster, Crassostrea gigas (Thumberg), is described. At the straight-hinge stage, the mantle wall produces an elevation on either side of the posterior portion of the body, then these original gills project farther outward. Before metamorphosis, the right and left inner demibranches were mixed with each other behind the foot, dividing the mantle cavity into two parts (inhalant and exhalant chambers). Each demibra-nch bears 7 to 8-paired filaments. Then both filaments of a pair grow simultaneously throughout their length. When spat is about 3mm to 4mm in length, the left and the right outer demibranch develop respectively in the same way as their inner demibranch.