本片是一部法国纪录片片，由让·潘勒维导演，由主演。
剧情简介：In mud flats along the coast of Brittany we watch acera, small ball-shaped mollusks that are about two inches in diameter. They rest in mud; then, in water, they dance, their skirt-like hood spreading like a dervish's cassock. They spin and spin. The film adds musical accompaniment. We watch them mate and secrete eggs: acera are both male and female, and can form chains with other acera in which they simultaneously mate as a male and as a female. The eggs hatch, and the cycle begins again.
外文名：Acéra ou Le bal des sorcières
别名：Acera， or the Witches' Dance
类型：纪录片 / 短片
地区：法国
导演：让·潘勒维 / Geneviève Hamon
