Fertilization and male fertility in the rotifer Brachionus plicatilis

The role of males in fertilization in the rotifer Brachionus plicatilis was examined. Neonate mictic females sometimes escaped fertilization even when sperm were present in their pseudocoeloms. Males made a major contribution to this fertilization failure through temporary infertility. As males aged, sperm numbers and motility decreased. Maternal diet was found to play a primary role in determining the fertilizing capacity of the F₁ males. Females from log phase populations produced males with higher sperm counts and motility than females from stationary phase populations. A conditioning factor in the medium may increase sperm number and fertilization rate.