title: Selective retention of chloroplasts by algivorous heliozoa: Fortuitous chloroplast symbiosis?
abstract: The selective retention of functionally intact chloroplasts by the algivorous centroheliozoa (protists) Acanthocystis serrata, Raphidocystis tubifera and Chlamydaster fimbriatus is documented by ultrastructural accounts of individual cells from natural habitats. The plastids are derived from different algae. The 'plastidoplasm' may be bounded by two or three membranes, in the latter case the outer membrane having been provided by the centroheliozoon. Such symbioses only involve certain species of centroheliozoa, and are short-lived. These appear to be examples of fortuitous symbioses and their study may provide clues as to the mechanisms by which stable symbioses are established.
authors.affiliation: Department of Zoology, University of Bristol, Bristol, England.
authors.forename: D J
authors.initials: DJ
authors.lastname: Patterson
authors.forename: M
authors.initials: M
authors.lastname: Dürrschmidt