Differential expression of proteins during the development of spionid Pseudopolydora vexillosa larvae. COM: competent larvae, META: newly metamorphosed juveniles. (A) Number of protein spots observed in each stage. (B) Number of protein spots showing a 2-fold increase in spot volume between successive stages, and (C) number of protein spots that showed a 2-fold decrease in spot volume between successive stages. (D) Number of spots that showed a significant difference in both their presence/absence and their spot volumes between successive stages by Student's t test (p < 0.02), n = 2.