Induction and Ecological Significance of Gigantism in the Rotifer Asplanchna sieboldi

Dietary alpha-tocopherol and cannibalism together induce the giant, campanulate morphotype. Campanulates, unlike the two smaller female morphotypes, do not respond to alpha-tocopherol by forming male-producing offspring. Campanulate production probably is very significant ecologically, allowing a rapid, adaptive response to increased prey size and a rapid reproductive rate uninter-rupted by sexuality and consequent dormancy.