develops from OBO_REL:part_of (UNDECLARED) Kupffer's vesicle Small but distinctive epithelial sac containing fluid, located midventrally posterior to the yolk cell or its extension, and transiently present during most of the segmentation period. Kimmel et al, 1995. Kupffer's vesicle has been compared to the mouse embryonic node. Drummond et al, 2005. TAO:0000001 teleost_anatomy forerunner cell group tail bud