The Biology of Free‐Living Heterotrophic Flagellates.

Systematists and taxonomists have tried for decades to find order in the seemingly endless variety of “algae” and “protozoa.” Prominent characters such as pigmentation, mode of reproduction, and general morphology have often provided important clues for predicting evolutionary affinities. In the present volume edited by Drs. Patterson and Larsen the uniting theme is heterotrophic nutrition and flagellation. Included in this group are about 300 genera and 2,000 species (Patterson and Larsen) distributed in 15 phyla, with only the animalia not represented among the six eukaryotic kingdoms (Cavalier-Smith). As the editors point out in their General Introduction, the heterotrophic flagellates are not a natural phylogenetic grouping. Indeed problems arise even in selecting organisms for consideration. In the chytrid-like fungi, which are major contributors to the planktonic biota, the reproductive stage is flagellated but not heterotrophic whereas the vegetative cell is heterotrophic but not flagellated (Moss). Yet these are included as “heterotrophic flagellates. ”