Not routinely, however as circumstances arise you should consider whether your membership gives rise to a conflict of interest and whether you should declare it at that point in time.
Nid fel mater o drefn; fodd bynnag, wrth i amgylchiadau godi dylech ystyried a yw eich aelodaeth yn arwain at wrthdaro buddiannau ac a ddylech ei datgan bryd hynny.