The mechanism of the ring trap of the predacious hyphomyceteDactylella brochopaga Drechsler

Summary A mutant ofDactylella brochopaga which produces giant functional ring traps, was isolated and studied. From experiments in which such traps were compressed, punctured and caused to inflate and deflate in environments of varying humidity levels it was concluded that trap cells are inflated by absorbing water or water vapour directly through their cell walls from their surroundings. Water entry occurs by osmosis, is initiated by a sudden increase in plasma membrane permeability and the increased pressure causes the inner of the two cell wall layers either to expand elastically or to unfold from a prepackaged state. In the fully inflated cell this wall layer becomes plastic finally.