Balantidium polyvacuolum Li, 1963, an obligatory intestinal symbiont of Xenocyprinae fish, mainly inhabits in the luminal contents of the middle and hindgut. Though the description and some revisions are given at both light and scanning electronic microscopic levels, the morphological data are still incomplete since fine structural data with taxo nomic values are still unavailable. This study examined the ultrastructural anatomy of this Chinese balantidium that inhabits in the intestines ofXenocypris davidi collected from the Jialing River in S...
