Unrooted NJ of SSU (1384 nt region) of all named species, previously barcoded strains, and putative new amicronucleate species. The tree was constructed using the Kimura 2-parameter methods and is drawn to scale. Bootstrap test (1000 replicas) percentages >50% are shown at nodes. Red: species known only from amicronucleate isolates. Black: species known only from micronucleate isolates. Fuchsia: species with both micronucleate and amicronucleate isolates. Genera: T., Tetrahymena; D., Dexiostoma; C., Colpidium; G., Glaucoma.