Genus: Postoral kineties usually to left of oral poykinetids (Illustrated Guide, 1985).
Left edge is more curved than right edge; cytopharynx with numerous strong fibrils; ectoplasm with
numerous fusiform trichocysts; macronucleus oval; one to several micronulei (Kudo, 1966).
Species: Cell body 60-80 μm long; macronucleus short sausage-shaped; a single micronucleus; a single contractile vacuole (Kahl, 1930). |
50 μm
100 μm
150 μm; x 400
31 μm
63 μm
94 μm; x 640
* F. depressa (Stokes, 1886) (F. parvula Penard, 1922): Cell body 60-80 μm long; macronucleus short sausage-shaped; a single micronucleus; a single contractile vacuole (Kahl, 1930).
F. acuminata Ehrenberg, 1833 (F. acuminata var. angustata Kahl, 1931; F. arenaria Kahl, 1933): Ovoid, 60-100 μm long; cytostome ovoid; a single macronucleus and single micronucleus anterior; a single contractile vacuole central; numerous large trichocysts (Carey, 1992).
F. macrostoma Dragesco, 1960: Ovoid, small 125-230 μm long; very large oral aperture, well defined suture; a large macronucleus with single micronucleus; a contractile vacuole posterior; many large trichocysts; pellicle with interkinetal striation (Carey, 1992)
Frontonia elliptica Beardsley, 1902: Cell body 150-200 μm long; macronucleus ovoid, with a single micronucleus large, ovoid in shape; two contractile vacuoles present (Kahl, 1930).
Frontonia fusca (Quennerstedt 1869): Cell body 150-200 μm long; macronucleus ovoid, with a small micronucleu; a single contractile vacuole located at posterior half of the cell body (Kahl, 1930).