Observations of Paramecium Occupying Arboreal Standing Water in Costa Rica

Some observations on the natural history of the Paramecium—Heliconia system are presented. The pattern of distribution in the wet season seams to be either a random colonization or a colonizing bias toward younger bracts, but ultimately the mosquito larvae in the older bract build up, resulting in the death of the local Paramecium population. The dry season pattern appears to be different at least in that there are very few mosquito larvae. The observation of Maguire and Belk (1967) that Paramecium do get to bromeliads was repeated. Experiments were performed demonstrating that if Paramecium do get to bromeliads, the biological interactions between the Paramecium and the regular microfauna of the bromeliad are such that the Paramecium are driven to extinction.