The effect of ciliate contamination in mass cultures of the rotifer, Brachionus plicatilis O.F. Müller

High levels of ciliates in mass cultures of the rotifer Brachionus plicatilis result in considerably reduced yield. This is caused by the activity of the ciliates which bring about aggregation of food algae and hence reduce their availability to the rotifers. Extracellular products of the ciliates do not seem to be involved. Ciliates thrive in Dunaliella tertiolecta cultures, both living and pasteurized, and with or without antibiotics.The ciliates compete with the rotifers, and their presence can become undesirable. some practical solutions to control or eradicate ciliates from rotifer cultures are suggested.