Isozyme changes during larval development of Penaeus chinensis

Isozyme changes during early development of Penaeus chinensis are described for six enzymes (EST, AMY MDH, GDH, Gd and LDH) by means of polyacrylamide gel vertical plate electrophoresis. The results show that the number of isozymes varies considerably and the enzyme activity also rises gradually with development. The band number of EST increases from 1 in nauplius stage to 6 in postlarval stage. There are three types of AMY, α-AMY, R-AMY and Q-AMY. The phenotype of LDH changes slightly, showing the same pattern except nauplius in all the stages. The remaining three enzymes (MDH, Gd and GDH) have more bands and their isozyme number also increases with development.